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Blockchain in Healthcare: Bridging Trust in response to COVID-19

Blockchain in Healthcare: Bridging Trust in response to COVID-19
Link to our article: https://block.co/blockchain-in-healthcare/
There’s never been a better time to provide proof-of-health solutions in the healthcare system globally. While it’s difficult to comprehend the significance of the role that technology may offer in such difficult times, essentially it can be nailed down to its basic concept of simplifying work and coordinating activities, which could have helped avoid the worst crisis people have experienced in their lifetime. If the healthcare system would adopt technological innovations in the early stages, it could have benefited and saved many lives.
Although the healthcare system has traditionally been slow in embracing the latest digital solutions, just like many other industries, we’ve observed in a previous article how the Covid-19 crisis has accelerated the adoption of digital technologies on a global scale in several industries, including healthcare.
The latest webcast brought to the audience by Block.co hosted some high profile experts from the industry. They illustrated how blockchain especially, together with other technologies such as IoT, and AI could in the future help elevate prompt responses, and provide more secure and efficient storage of data, something that has been missed in the recent pandemic.
Ahmed Abdulla from Digipharm, Dr. Alice Loveys from EY, and Dimitrios Neocleous from VeChain were hosted by Georgina Kyriakoudes, one of the first in the world to hold an MSc in Digital Currency, founder of Dcentric.Health and creator of the permissioned blockchain ecosystem app called Aria, which aims to transform the patient healthcare experience by giving individuals full control of their medical records.
Blockchain’s benefits in healthcare are primarily identified by efficiency, specifically on the transfer of data, facilitation of goods transport via the supply chain, prevention of counterfeit medicines sale, secure storage, and exchange of data around ID management. The impressive projects all the webcast guests have developed in the industry enable just these features, from the digitization of patient records to storage and exchange of medical data as well as easier processing of funds.
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Ahmed Abdulla founded Digipharm with the idea of issuing tokens to allow patients to be in control of their medical records at all times. Moreover, tokens are issued to be paid for anonymously sharing personal medical data to help research; pay for healthcare based on how it has improved quality of life.
We have experienced a disparity in Covid-19 tests costs around the world. For instance, getting tested in Cyprus costs around €60 while in the US it may add up to a few thousand dollars. This is due to the way countries arrange payment setups from payers to providers. Blockchain empowers people to take ownership of their records and funds while providing transparency of processes. This is where blockchain can be robust, by increasing transparency and allowing the patient to secure money transfer and hold their own records”, stated Ahmed.
His work as blockchain advisor at the UN Economic Commission for Europe is helping set up standards for the blockchain ecosystem, namely how the system should be used safely, and in a way that benefits all stakeholders.
“I lead the blockchain and healthcare team at the UN center for trade facilitation and e-business where we developed a blockchain and trade facilitation white paper; the second phase will soon provide an advanced technology advisory board to advise private or public stakeholders on what’s the best technology to use. It might not always be blockchain, hence we first understand and then advise if the tech is right for them or not. Blockchain is clunky, expensive, and not always proper for the organization we work with”, continued the blockchain expert.
Most people may prefer public and permissionless blockchain because it has major advantages over a private and permissioned one. Transparency stands out for the way the ledger is shared and for due diligence becoming unnecessary as a result. This means costs are also cheaper, in the range of 100% lower. On the other hand, a public decentralized blockchain has a major disadvantage since no legal framework is laid out. This means uncertainty as there is still a grey area in the legal field that might create confusion.
Dimitrios Neocleous is Ecosystem Manager at VeChain Tech and directly supported digital and technological solutions provider I-DANTE with the creation of the E-NewHealthLife and the E-HCert for the Mediterranean Hospital of Cyprus. Both apps give patients control over their health records, improve medical data sharing, and increase hospital operational efficiencies by simplifying the process of visiting a hospital.
E-NewHealthLife is a complex ecosystem solution that starts from a patient’s visit to an emergency room. A card with the reason for a patient’s visit is issued; it gets time-stamped; the patient is sent to the waiting room; once the patient’s turn comes and the medical check is completed, the card is scanned and the visit is closed. Patients can digitally access all diagnoses that took place anytime at the hospital.
“The platform produces a digital health passport, which is an encrypted non-fungible card that patients can use to identify themselves automatically when registering at the hospital’s emergency room. The passport is stored within a mobile app called E-HCert, which keeps track of each patient’s medical data and can be shared as needed”, announced Dimitrios.
E-HCert App is a Covid-19 lab test electronic wallet and pushes up the results of a patient who’s been tested for COVID. It has been proven to be very successful so far; currently, 2000 people who transited through the Larnaca airport in Cyprus have downloaded the app. With time-stamped records, it’s able to provide data such as the day and time when the sample was collected, it offers immutability, security, and integrity of data.
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“Covid-19 showed a deficiency in healthcare. The spread of the virus could have been prevented if we had digitization of processes and transparency of data through blockchain, and transfer of data through an authorized share of records. An open permissionless decentralized blockchain helps bring ownership of medical records back to the patient, and that is not possible in a centralized system”, continued the VeChain representative.
Dr. Alice Loveys is EY ‘s healthcare blockchain leader in the US and has been at the forefront of emerging healthcare technologies for her entire career including being a pioneer in electronic health record adoption, health information exchange, and privacy and security.
She believes that “blockchain technology is like a plumbing system that brings clean and transparent trusted data that can be used. It’s not proper for a track and trace system as it invades privacy unless there is the consent from patients, in that case, blockchain transparent share of data would be extremely useful for medical research and testing”.
One problem we experienced during the crisis is the confusion that arose with divulged information and the frustration that comes with it. People do not understand anymore which information can be trusted; at first, it looked like COVID-19 symptoms were not dangerous, then it came out that they actually were. Masks were not useful at the beginning, then they suddenly became necessary.
“Blockchain could have prevented lockdown and economic crisis through data management in that a much faster response would have been provided to tackle misinformation because blockchain can help manage data from different sources”, continues Dr. Loveys. “Moreover, it’s a great way to protect the database. Instead of moving any private sensitive medical data through the more traditional digital systems, blockchain simply allows us to send an algorithm, encrypted data that safeguards the information. It’s not a great use as a database as it does not scale, therefore we would not be able to store information for billions of people in it. But for the data that is in the blockchain, using algorithms, makes it very convenient and secure”.
Another topic discussed during the webcast was the GDPR compliance for blockchain. GDPR (General Data Protection Regulation) was created before blockchain therefore it doesn’t account for decentralized technologies. Generally speaking, it all comes down to how the technology is used and what kind of data is incorporated in it. Timestamping data without invading anyone’s privacy, or timestamp of consented data, should determine no issue at all. This is what privacy by design stands for, taking human values into account in a well-defined manner throughout the whole process.
Block.co, powered by the University of Nicosia, is establishing itself as a global leader in the issuance of digital immutable and secure certificates timestamped on the Bitcoin blockchain. In the field of healthcare, it could include medical records, prescription issuance, insurance disputes, supply chain documentation, and any type of verifiable certificate that requires authenticity at its core.
For more info, contact Block.co directly or email at [[email protected]](mailto:[email protected]).
Tel +357 70007828
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Blockchain in Healthcare – Webcast Q&A

Blockchain in Healthcare – Webcast Q&A
On our website, you can find the original article: https://block.co/webcastqa-blockchain-in-healthcare/
Block.co third webcast ” Blockchain in Healthcare: Bridging Trust in response to COVID-19“ received amazing feedback! We gathered some of the best experts in the field, Georgina Kyriakoudes, Ahmed Abdulla, Dimitri Neocleous, Dr. Alice Loveys to share their experience in the industry and discuss with us the latest updates in the sphere of Healthcare! In its third series of webcasts, Block.co gathered 253 people watching the event from 59 different countries, for a 90-minute webcast where guests answered participants’ questions.
Below is a list of the questions that were made and were not answered due to time constraints during the Blockchain in Healthcare webcast. Please note that the below information is only for educational purposes!
Question 1: I like what Dimitrios was saying regarding ownership and transfer. Health and social care have invested much in Information Management systems and processes. Transfer between NHS and social care is a typical block. Can you elaborate on how the blockchain sits across that – leapfrogs yet goes with the grain of what is already there in terms of shared records protocols, the exponentially growing types of professionals, pharmacists, careers, etc. that need early access to these records for better decision making.
Block.co Team Answer: Blockchain technology has the potential to improve healthcare, placing the patient at the center of the health care ecosystem, while providing security, privacy, and interoperability of health data. Blockchain could provide a new model for health information exchanges and transform electronic medical records to be more efficient, disintermediated, and secure. While it is not a cure, this new, Blockchain in Healthcare rapidly evolving field provides a sandbox for experimentation, investment, and proof-of-concept testing.
Healthcare systems around the world are preparing road maps that define critical policy and technical components needed for nationwide interoperability, including:
  • Ubiquitous, secure network infrastructure
  • Verifiable identity and authentication of all participants
  • Consistent illustration of authorization to access electronic health data, and several other requirements.
However, current technologies don’t totally address these necessities, and as a result, they face limitations associated with security, privacy, and full ecosystem interoperability.
Blockchain technology creates distinctive opportunities to scale back complexity, improve trustless collaboration, and create secure and immutable data. National Healthcare Systems need to track this rapidly evolving field to identify trends and sense the areas where government support may be needed for the technology to realize its full potential in health care. To form blockchain’s future, they ought to take into account mapping and gathering the blockchain ecosystem, establishing a blockchain framework to coordinate early-adopters, and supporting a pool for dialogue and discovery.
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Question 2: What about the “compatibility” of blockchain solutions in healthcare with GDPR and/or other regulations about personal data protection.
Block.co Team Answer: The General Data Protection Regulation (GDPR), Europe’s new framework for data protection laws, has a vital impact on healthcare organizations. During this more and more patient-centric world where global healthcare organizations collect a large set of data on patients to produce improved health outcomes, this increased regulation has an even larger impact.
GDPR presents challenges across all industries and includes language that has a special impact on healthcare. The regulation defines “personal” data as “any information relating to an identified or identifiable natural person (data subject); an identifiable natural person is one who can be identified, directly or indirectly, in particular by reference to an identifier such as a name, an identification number, location data, an online identifier or to one or more factors specific to the physical, physiological, genetic, mental, economic, cultural or social identity of that natural person.” On top of this definition, GDPR contains three extra, important definitions that pertain to health data:
  1. “Data concerning health” is defined by the GDPR as “personal data related to the physical or mental health of a natural person, including the provision of health care services, which reveal information about his or her health status.”
  2. “Genetic data” is outlined by the GDPR as “personal data relating to inherited or acquired genetic characteristics of a natural person which give unique information about the physiology or the health of that natural person and which result, in particular, from an analysis of a biological sample from the natural person in question.”
  3. “Biometric data” is “personal data resulting from specific technical processing relating to the physical, physiological, or behavioral characteristics of a natural person, which allows or confirms the unique identification of that natural person, such as facial images or dactyloscopic data.”
As described in Article 6 of GDPR, processing of personal data is considered lawful if: (1) the data subject has given consent; (2) it is necessary for the performance of a contract to which the data subject is a party; (3) it is necessary for compliance with a legal obligation; (4) it is necessary to protect the vital interest of the data subject or another natural person; (5) it is necessary for the performance of a task carried out in the public interest; (6) it is necessary for the purposes of the legitimate interests pursued by the controller or third party.
However, healthcare organizations that usually manage health data, have an added responsibility to take care of “data concerning health,” “genetic data,” and “biometric data” to a higher standard of protection than personal data, in general. GDPR prohibits the processing of these forms of health data unless one of the three conditions below would apply as per Article 9.
a. The data subject must have given “explicit consent.”
b. “Processing is necessary for the purposes of preventive or occupational medicine, for the assessment of the working capacity of the employee, medical diagnosis, the provision of health or social care or treatment or the management of health or social care systems and services …”
c. “Processing is necessary for reasons of public interest in the area of public health, such as protecting against serious cross-border threats to health or ensuring high standards of quality and safety of health care and of medicinal products or medical devices …”
Consent VS Explicit Consent – If one pays attention, there’s a difference in the GDPR’s health data use conditions (calls for “explicit consent”) and the general definition (calls for “consent”). Thus, there’s an ongoing debate as to what constitutes the difference between “unambiguous” and “explicit” consent. Despite the debate and the final legal clarifications, there is no doubt that in the purposes of the healthcare the “explicit consent” must have the strongest agreement form listing in detail the use(s) of data and covering the cases of data transfers and storage.
Question 3: How can we use blockchain technology by the government in Africanflavored government, say by Ministry of health to have patient autonomy of medical records that can be accessed by any government hospital irrespective of the ailment and record printed by the previous hospital and doctor, such as referral cases without having to open a new file in the referred hospital.
Block.co Team Answer: Perhaps that would be an ideal implementation of the Block.co solution issuing a digital certificate of medical examination on an Open Public Blockchain such as the Bitcoin blockchain, that would be decentralized in nature, easy to validate online without any special wallets, and would be provided by the patient on-demand, to refer to treatments received in other hospitals or areas. But this would require that the practitioner is aware and can use the open-source code or use Block.co services to issue these certificates. Alternatively, there could be the use of a wallet to store these medical credentials to be submitted on demand to health practitioners. Moreover, there would need to be an alignment of regulation in the matter as decentralized repositories are not recognized at the moment.

Question 4: Is there any data breach threat in the blockchain using a poorly protected private key at communication?
Block.co Team Answer: Millions of health care records have already been breached, and in attempts to combat this issue, solutions often result in the inaccessibility of health records. Health providers often send information to other providers, and this often ends up in mishandling of data, losing records, or passing on inaccurate and old data. In some cases, only one copy of an updated health record exists, and this may result in the loss of information. Health records often contain personal information such as names, social security numbers, and home addresses. When it comes to Blockchain in Healthcare, a poorly protected private key is always a factor to consider. A private key allows us to sign a transaction and spend funds residing in an address (public key) by providing ownership with the signature. It is a unique string of information that represents proof of identification inside the blockchain, which includes the right to access and control the participant’s wallet. It must be kept secret, as it is effectively a personal password. In the case that that private key is poorly protected, there is always a data breach threat.
Question 5: The medical record of a patient is owned by the patient. What happens if a doctor accesses the record without the consent of the patient? Using the smart contract, could there be a governing body, say a legal system that can call the doctor to order?
Block.co Team Answer: Rather than having each physical and electronic copies of records, blockchains may enable the shift to electronic health records (EHR). When looking at Blockchain in Healthcare, medical records on the blockchain would be within the management of the patient rather than a third party, through the patients’ private and public keys. Patients may then control access to their health records, making transferring information less cumbersome. Because blockchain ledgers are immutable, health information may not be deleted or tampered with. Blockchain transactions would be accompanied by a timestamp, permitting those with access to maintain updated information. The doctor would not be able to access the record without the consent of the patient. A patient would need to sign the transaction in a smart contract in order to transfer patient details to the doctor.
Question 6: So, how are private data protected when the patient is simply notified that unauthorized access just took place on her medical record? and, how are the negative results of this breach rectified towards the patient?
Block.co Team Answer: The patient would be notified to sign a transaction enabling access to the party requesting access to the specific medical record. In other cases, there could be a multi-signature wallet requiring multiple transactions in the cases where the patient may need assistance, for example, when underage or when not in a healthy state of mind, or being non-responsive or in critical condition. The patient needs to be responsible for his own data and be empowered through awareness and know-how of this technology. With great power, comes also great responsibility, although it is yet a challenge to enable computer illiterate people to interact with this technology.
Question 7: Can the same record of a patient still be shared with private hospitals and say another government/private hospital abroad on the same blockchain?
Block.co Team Answer: Depending on whether the information is on a public blockchain or a private blockchain. When on a private blockchain, they will need to be granted permission to access the blockchain accordingly.
Question 8: No one has directly spoken about ownership where a large research institution/ consortium is working with the data – it is not solely the person who has said so…
Block.co Team Answer: Indeed, it is solely not the person who has a say so. Technology may be used in both evil and good ways and it is still the obligation and responsibility of people within governments to ensure human liberties and rights are preserved when utilizing such powerful technologies such as blockchain and sometimes the combination of blockchain with AI, IoT, and biometrics. Blockchain in Healthcare, in the same way, that it can empower individuals and increase their standard of living and prosperity, at the same time, it can also empower corrupt governments with alternative agendas and totalitarian states. Block.co believes it is most important for people to be educated around the matter and be able to form a voice and movement to safeguard their human liberties and rights, hence our continuous effort on discussing these matters with our community and providing education, powered by the pioneers in the space, the University of Nicosia.
We would like to thank everyone for attending our webcast and hoping to interact with you in future webinars. If you would like to watch the webinar again, then click here!
For more info, contact Block.co directly or email at [email protected].
Tel +357 70007828
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DEDIQATED 2020 - Full Livestream Download

DEDIQATED 2020 | 20 Years of Q-dance Livestream The full liveset can be downloaded via a torrent client. Here is a link to the spreadsheet with the magnet / torrent link: https://docs.google.com/spreadsheets/d/13q7B9Fqfg1ZN8EiPSX1yrv7Wa21W_vtdN65V0eR4oQU/
I am not gonna explain how to download with torrents, since I expect this is common knowledge. If you use BitTorrent or μTorrent, shame on you. Get a good torrent client like qBittorrent or Deluge, they dont include advertisements and work as well, if not better.
Note: If you have issues with the download not strarting, you can add my seedbox as a peer manually: 185.45.195.189:20117
Timestamps of the full stream: 00:08:25 | Early Rave Rebels (Buzz Fuzz, Franky Jones, Gizmo & The Dark Raver) 00:32:26 | The Qlubtempo Parade (Luna, Pavo, Dana, Pila & A*S*Y*S) 01:02:10 | Fusion Records (Zany, Donkey Rollers, The Pitcher & MC DV8) 01:19:23 | Bella Hardstyle Italia (T'N'T, Zatox & Tatanka) 01:48:24 | Qlimax 01:52:35 | Masters of Melody Pt.1 (Frontliner, Bass Modulators & Max Enforcer) 02:14:49 | In Qontrol 02:17:27 | Praise the Reverse Bass (DJ Isaac, Technoboy & Tuneboy) 02:40:59 | Happy Birthday Q-dance 02:42:30 | Viva Hollandia (Ruthless, Outsiders, Deepack, Dr. Rude & The Viper) (03:05:39 - 03:10:49 | Rest in peace audio) 03:17:32 | Defqon.1 /w World of Madness (Headhunterz, Wildstylez & Noisecontrollers) 04:04:13 | Millenium Hardcore Mayhem (Endymion, Evil Activities, Promo & Art of Fighters) 04:35:22 | Scantraxx Recordz (The Prophet, D-Block & S-te-Fan & Devin Wild) 04:56:52 | The Land Down Under (Code Black, Audiofreq & Outbreak) 05:12:38 | The Best of Power Hour (05:32:19 - 05:36:30 | Villain takes off in a giant hamster ball on a journey to explore the crowd, which refuses to bring him back to stage) 06:13:26 | Dirty Workz (Coone, Da Tweekaz, Hard Driver & Psyko Punkz (incl. Sven (KELTEK)) 06:40:27 | Q-BASE: The Legacy 06:43:56 | Birth of Raw (Ran-D, Adaro, B-Front & Crypsis) 07:23:40 | Masters of Melody Pt.2 (Atmozfears, Audiotricz, KELTEK & Sound Rush) 07:55:27 | Future Heroes (Frequencerz, Sub Zero Project, Phuture Noize, Warface, D-Sturb, Sefa) 08:41:50 | Hardcore 2.0 (Korsakoff, Mad Dag, Partyraiser & Dr. Peacock) 09:16:16 | Hardstyle Top 25 10:13:40 | Closing + Endshow
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Bitcoin (BTC)A Peer-to-Peer Electronic Cash System.

Bitcoin (BTC)A Peer-to-Peer Electronic Cash System.
  • Bitcoin (BTC) is a peer-to-peer cryptocurrency that aims to function as a means of exchange that is independent of any central authority. BTC can be transferred electronically in a secure, verifiable, and immutable way.
  • Launched in 2009, BTC is the first virtual currency to solve the double-spending issue by timestamping transactions before broadcasting them to all of the nodes in the Bitcoin network. The Bitcoin Protocol offered a solution to the Byzantine Generals’ Problem with a blockchain network structure, a notion first created by Stuart Haber and W. Scott Stornetta in 1991.
  • Bitcoin’s whitepaper was published pseudonymously in 2008 by an individual, or a group, with the pseudonym “Satoshi Nakamoto”, whose underlying identity has still not been verified.
  • The Bitcoin protocol uses an SHA-256d-based Proof-of-Work (PoW) algorithm to reach network consensus. Its network has a target block time of 10 minutes and a maximum supply of 21 million tokens, with a decaying token emission rate. To prevent fluctuation of the block time, the network’s block difficulty is re-adjusted through an algorithm based on the past 2016 block times.
  • With a block size limit capped at 1 megabyte, the Bitcoin Protocol has supported both the Lightning Network, a second-layer infrastructure for payment channels, and Segregated Witness, a soft-fork to increase the number of transactions on a block, as solutions to network scalability.

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1. What is Bitcoin (BTC)?

  • Bitcoin is a peer-to-peer cryptocurrency that aims to function as a means of exchange and is independent of any central authority. Bitcoins are transferred electronically in a secure, verifiable, and immutable way.
  • Network validators, whom are often referred to as miners, participate in the SHA-256d-based Proof-of-Work consensus mechanism to determine the next global state of the blockchain.
  • The Bitcoin protocol has a target block time of 10 minutes, and a maximum supply of 21 million tokens. The only way new bitcoins can be produced is when a block producer generates a new valid block.
  • The protocol has a token emission rate that halves every 210,000 blocks, or approximately every 4 years.
  • Unlike public blockchain infrastructures supporting the development of decentralized applications (Ethereum), the Bitcoin protocol is primarily used only for payments, and has only very limited support for smart contract-like functionalities (Bitcoin “Script” is mostly used to create certain conditions before bitcoins are used to be spent).

2. Bitcoin’s core features

For a more beginner’s introduction to Bitcoin, please visit Binance Academy’s guide to Bitcoin.

Unspent Transaction Output (UTXO) model

A UTXO transaction works like cash payment between two parties: Alice gives money to Bob and receives change (i.e., unspent amount). In comparison, blockchains like Ethereum rely on the account model.
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Nakamoto consensus

In the Bitcoin network, anyone can join the network and become a bookkeeping service provider i.e., a validator. All validators are allowed in the race to become the block producer for the next block, yet only the first to complete a computationally heavy task will win. This feature is called Proof of Work (PoW).
The probability of any single validator to finish the task first is equal to the percentage of the total network computation power, or hash power, the validator has. For instance, a validator with 5% of the total network computation power will have a 5% chance of completing the task first, and therefore becoming the next block producer.
Since anyone can join the race, competition is prone to increase. In the early days, Bitcoin mining was mostly done by personal computer CPUs.
As of today, Bitcoin validators, or miners, have opted for dedicated and more powerful devices such as machines based on Application-Specific Integrated Circuit (“ASIC”).
Proof of Work secures the network as block producers must have spent resources external to the network (i.e., money to pay electricity), and can provide proof to other participants that they did so.
With various miners competing for block rewards, it becomes difficult for one single malicious party to gain network majority (defined as more than 51% of the network’s hash power in the Nakamoto consensus mechanism). The ability to rearrange transactions via 51% attacks indicates another feature of the Nakamoto consensus: the finality of transactions is only probabilistic.
Once a block is produced, it is then propagated by the block producer to all other validators to check on the validity of all transactions in that block. The block producer will receive rewards in the network’s native currency (i.e., bitcoin) as all validators approve the block and update their ledgers.

The blockchain

Block production

The Bitcoin protocol utilizes the Merkle tree data structure in order to organize hashes of numerous individual transactions into each block. This concept is named after Ralph Merkle, who patented it in 1979.
With the use of a Merkle tree, though each block might contain thousands of transactions, it will have the ability to combine all of their hashes and condense them into one, allowing efficient and secure verification of this group of transactions. This single hash called is a Merkle root, which is stored in the Block Header of a block. The Block Header also stores other meta information of a block, such as a hash of the previous Block Header, which enables blocks to be associated in a chain-like structure (hence the name “blockchain”).
An illustration of block production in the Bitcoin Protocol is demonstrated below.

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Block time and mining difficulty

Block time is the period required to create the next block in a network. As mentioned above, the node who solves the computationally intensive task will be allowed to produce the next block. Therefore, block time is directly correlated to the amount of time it takes for a node to find a solution to the task. The Bitcoin protocol sets a target block time of 10 minutes, and attempts to achieve this by introducing a variable named mining difficulty.
Mining difficulty refers to how difficult it is for the node to solve the computationally intensive task. If the network sets a high difficulty for the task, while miners have low computational power, which is often referred to as “hashrate”, it would statistically take longer for the nodes to get an answer for the task. If the difficulty is low, but miners have rather strong computational power, statistically, some nodes will be able to solve the task quickly.
Therefore, the 10 minute target block time is achieved by constantly and automatically adjusting the mining difficulty according to how much computational power there is amongst the nodes. The average block time of the network is evaluated after a certain number of blocks, and if it is greater than the expected block time, the difficulty level will decrease; if it is less than the expected block time, the difficulty level will increase.

What are orphan blocks?

In a PoW blockchain network, if the block time is too low, it would increase the likelihood of nodes producingorphan blocks, for which they would receive no reward. Orphan blocks are produced by nodes who solved the task but did not broadcast their results to the whole network the quickest due to network latency.
It takes time for a message to travel through a network, and it is entirely possible for 2 nodes to complete the task and start to broadcast their results to the network at roughly the same time, while one’s messages are received by all other nodes earlier as the node has low latency.
Imagine there is a network latency of 1 minute and a target block time of 2 minutes. A node could solve the task in around 1 minute but his message would take 1 minute to reach the rest of the nodes that are still working on the solution. While his message travels through the network, all the work done by all other nodes during that 1 minute, even if these nodes also complete the task, would go to waste. In this case, 50% of the computational power contributed to the network is wasted.
The percentage of wasted computational power would proportionally decrease if the mining difficulty were higher, as it would statistically take longer for miners to complete the task. In other words, if the mining difficulty, and therefore targeted block time is low, miners with powerful and often centralized mining facilities would get a higher chance of becoming the block producer, while the participation of weaker miners would become in vain. This introduces possible centralization and weakens the overall security of the network.
However, given a limited amount of transactions that can be stored in a block, making the block time too longwould decrease the number of transactions the network can process per second, negatively affecting network scalability.

3. Bitcoin’s additional features

Segregated Witness (SegWit)

Segregated Witness, often abbreviated as SegWit, is a protocol upgrade proposal that went live in August 2017.
SegWit separates witness signatures from transaction-related data. Witness signatures in legacy Bitcoin blocks often take more than 50% of the block size. By removing witness signatures from the transaction block, this protocol upgrade effectively increases the number of transactions that can be stored in a single block, enabling the network to handle more transactions per second. As a result, SegWit increases the scalability of Nakamoto consensus-based blockchain networks like Bitcoin and Litecoin.
SegWit also makes transactions cheaper. Since transaction fees are derived from how much data is being processed by the block producer, the more transactions that can be stored in a 1MB block, the cheaper individual transactions become.
https://preview.redd.it/depya70mf3151.png?width=1601&format=png&auto=webp&s=a6499aa2131fbf347f8ffd812930b2f7d66be48e
The legacy Bitcoin block has a block size limit of 1 megabyte, and any change on the block size would require a network hard-fork. On August 1st 2017, the first hard-fork occurred, leading to the creation of Bitcoin Cash (“BCH”), which introduced an 8 megabyte block size limit.
Conversely, Segregated Witness was a soft-fork: it never changed the transaction block size limit of the network. Instead, it added an extended block with an upper limit of 3 megabytes, which contains solely witness signatures, to the 1 megabyte block that contains only transaction data. This new block type can be processed even by nodes that have not completed the SegWit protocol upgrade.
Furthermore, the separation of witness signatures from transaction data solves the malleability issue with the original Bitcoin protocol. Without Segregated Witness, these signatures could be altered before the block is validated by miners. Indeed, alterations can be done in such a way that if the system does a mathematical check, the signature would still be valid. However, since the values in the signature are changed, the two signatures would create vastly different hash values.
For instance, if a witness signature states “6,” it has a mathematical value of 6, and would create a hash value of 12345. However, if the witness signature were changed to “06”, it would maintain a mathematical value of 6 while creating a (faulty) hash value of 67890.
Since the mathematical values are the same, the altered signature remains a valid signature. This would create a bookkeeping issue, as transactions in Nakamoto consensus-based blockchain networks are documented with these hash values, or transaction IDs. Effectively, one can alter a transaction ID to a new one, and the new ID can still be valid.
This can create many issues, as illustrated in the below example:
  1. Alice sends Bob 1 BTC, and Bob sends Merchant Carol this 1 BTC for some goods.
  2. Bob sends Carols this 1 BTC, while the transaction from Alice to Bob is not yet validated. Carol sees this incoming transaction of 1 BTC to him, and immediately ships goods to B.
  3. At the moment, the transaction from Alice to Bob is still not confirmed by the network, and Bob can change the witness signature, therefore changing this transaction ID from 12345 to 67890.
  4. Now Carol will not receive his 1 BTC, as the network looks for transaction 12345 to ensure that Bob’s wallet balance is valid.
  5. As this particular transaction ID changed from 12345 to 67890, the transaction from Bob to Carol will fail, and Bob will get his goods while still holding his BTC.
With the Segregated Witness upgrade, such instances can not happen again. This is because the witness signatures are moved outside of the transaction block into an extended block, and altering the witness signature won’t affect the transaction ID.
Since the transaction malleability issue is fixed, Segregated Witness also enables the proper functioning of second-layer scalability solutions on the Bitcoin protocol, such as the Lightning Network.

Lightning Network

Lightning Network is a second-layer micropayment solution for scalability.
Specifically, Lightning Network aims to enable near-instant and low-cost payments between merchants and customers that wish to use bitcoins.
Lightning Network was conceptualized in a whitepaper by Joseph Poon and Thaddeus Dryja in 2015. Since then, it has been implemented by multiple companies. The most prominent of them include Blockstream, Lightning Labs, and ACINQ.
A list of curated resources relevant to Lightning Network can be found here.
In the Lightning Network, if a customer wishes to transact with a merchant, both of them need to open a payment channel, which operates off the Bitcoin blockchain (i.e., off-chain vs. on-chain). None of the transaction details from this payment channel are recorded on the blockchain, and only when the channel is closed will the end result of both party’s wallet balances be updated to the blockchain. The blockchain only serves as a settlement layer for Lightning transactions.
Since all transactions done via the payment channel are conducted independently of the Nakamoto consensus, both parties involved in transactions do not need to wait for network confirmation on transactions. Instead, transacting parties would pay transaction fees to Bitcoin miners only when they decide to close the channel.
https://preview.redd.it/cy56icarf3151.png?width=1601&format=png&auto=webp&s=b239a63c6a87ec6cc1b18ce2cbd0355f8831c3a8
One limitation to the Lightning Network is that it requires a person to be online to receive transactions attributing towards him. Another limitation in user experience could be that one needs to lock up some funds every time he wishes to open a payment channel, and is only able to use that fund within the channel.
However, this does not mean he needs to create new channels every time he wishes to transact with a different person on the Lightning Network. If Alice wants to send money to Carol, but they do not have a payment channel open, they can ask Bob, who has payment channels open to both Alice and Carol, to help make that transaction. Alice will be able to send funds to Bob, and Bob to Carol. Hence, the number of “payment hubs” (i.e., Bob in the previous example) correlates with both the convenience and the usability of the Lightning Network for real-world applications.

Schnorr Signature upgrade proposal

Elliptic Curve Digital Signature Algorithm (“ECDSA”) signatures are used to sign transactions on the Bitcoin blockchain.
https://preview.redd.it/hjeqe4l7g3151.png?width=1601&format=png&auto=webp&s=8014fb08fe62ac4d91645499bc0c7e1c04c5d7c4
However, many developers now advocate for replacing ECDSA with Schnorr Signature. Once Schnorr Signatures are implemented, multiple parties can collaborate in producing a signature that is valid for the sum of their public keys.
This would primarily be beneficial for network scalability. When multiple addresses were to conduct transactions to a single address, each transaction would require their own signature. With Schnorr Signature, all these signatures would be combined into one. As a result, the network would be able to store more transactions in a single block.
https://preview.redd.it/axg3wayag3151.png?width=1601&format=png&auto=webp&s=93d958fa6b0e623caa82ca71fe457b4daa88c71e
The reduced size in signatures implies a reduced cost on transaction fees. The group of senders can split the transaction fees for that one group signature, instead of paying for one personal signature individually.
Schnorr Signature also improves network privacy and token fungibility. A third-party observer will not be able to detect if a user is sending a multi-signature transaction, since the signature will be in the same format as a single-signature transaction.

4. Economics and supply distribution

The Bitcoin protocol utilizes the Nakamoto consensus, and nodes validate blocks via Proof-of-Work mining. The bitcoin token was not pre-mined, and has a maximum supply of 21 million. The initial reward for a block was 50 BTC per block. Block mining rewards halve every 210,000 blocks. Since the average time for block production on the blockchain is 10 minutes, it implies that the block reward halving events will approximately take place every 4 years.
As of May 12th 2020, the block mining rewards are 6.25 BTC per block. Transaction fees also represent a minor revenue stream for miners.
submitted by D-platform to u/D-platform [link] [comments]

How to Create Your Own Cryptocurrency Using Python 2020

A blockchain is a public database that irreversibly documents and authenticates the possession and transmission of digital assets. Digital currencies, like Bitcoin and Ethereum, are based on this concept. Blockchain is an exciting technology that you can use to transform the capabilities of your applications.
Of late, we’ve been seeing governments, organizations, and individuals using the blockchain technology to create their own cryptocurrencies—and avoid being left behind. Notably, when Facebook proposed its own cryptocurrency, called Libra, the announcement stirred many waters across the world.

What if you could also follow suit and create your own version of a cryptocurrency?

I thought about this and decided to develop an algorithm that creates a crypto.
I decided to call the cryptocurrency fccCoin.
In this tutorial, I’m going to illustrate the step-by-step process I used to build the digital currency (I used the object-oriented concepts of the Python programming language).
Here is the basic blueprint of the blockchain algorithm for creating the fccCoin:
class Block: def __init__(): #first block class pass def calculate_hash(): #calculates the cryptographic hash of every block class BlockChain: def __init__(self): # constructor method pass def construct_genesis(self): # constructs the initial block pass def construct_block(self, proof_no, prev_hash): # constructs a new block and adds it to the chain pass u/staticmethod def check_validity(): # checks whether the blockchain is valid pass def new_data(self, sender, recipient, quantity): # adds a new transaction to the data of the transactions pass u/staticmethod def construct_proof_of_work(prev_proof): # protects the blockchain from attack pass u/property def last_block(self): # returns the last block in the chain return self.chain[-1]
Now, let me explain what is taking place…
1. Building the first Block class A blockchain comprises of several blocks that are joined to each other (that sounds familiar, right?).
The chaining of blocks takes place such that if one block is tampered with, the rest of the chain becomes invalid.
In applying the above concept, I created the following initial block class
import hashlib import time class Block: def __init__(self, index, proof_no, prev_hash, data, timestamp=None): self.index = index self.proof_no = proof_no self.prev_hash = prev_hash self.data = data self.timestamp = timestamp or time.time() u/property def calculate_hash(self): block_of_string = “{}{}{}{}{}”.format(self.index, self.proof_no, self.prev_hash, self.data, self.timestamp) return hashlib.sha256(block_of_string.encode()).hexdigest() def __repr__(self): return “{} – {} – {} – {} – {}”.format(self.index, self.proof_no, self.prev_hash, self.data, self.timestamp)
As you can see from the code above, I defined the __init__() function, which will be executed when the Block class is being initiated, just like in any other Python class.
I provided the following parameters to the initiation function:
self—this refers to the instance of the Block class, making it possible to access the methods and attributes associated with the class; index—this keeps track of the position of the block within the blockchain; proof_no—this is the number produced during the creation of a new block (called mining); prev_hash—this refers to the hash of the previous block within the chain; data—this gives a record of all transactions completed, such as the quantity bought; timestamp—this places a timestamp for the transactions. The second method in the class, calculate_hash, will generate the hash of the blocks using the above values. The SHA-256 module is imported into the project to assist in obtaining the hashes of the blocks.
After the values have been inputted into the cryptographic hash algorithm, the function will return a 256-bit string representing the contents of the block.
This is how security is achieved in blockchains—every block will have a hash and that hash will rely on the hash of the previous block.
As such, if someone tries to compromise any block in the chain, the other blocks will have invalid hashes, leading to disruption of the entire blockchain network.
Ultimately, a block will look like this:
{ “index”: 2, “proof”: 21, “prev_hash”: “6e27587e8a27d6fe376d4fd9b4edc96c8890346579e5cbf558252b24a8257823”, “transactions”: [ {‘sender’: ‘0’, ‘recipient’: ‘Quincy Larson’, ‘quantity’: 1} ], “timestamp”: 1521646442.4096143 }
2. Building the Blockchain class The main idea of a blockchain, just as the name implies, involves “chaining” several blocks to one another.
Therefore, I’m going to construct a Blockchain class that will be useful in managing the workings of the whole chain. This is where most of the action is going to take place.
The Blockchain class will have various helper methods for completing various tasks in the blockchain.
Let me explain the role of each of the methods in the class.
a. Constructor method This method ensures the blockchain is instantiated.
class BlockChain: def __init__(self): self.chain = [] self.current_data = [] self.nodes = set() self.construct_genesis()
Here are the roles of its attributes:
b. Constructing the genesis block The blockchain requires a construct_genesis method to build the initial block in the chain. In the blockchain convention, this block is special because it symbolizes the start of the blockchain.
In this case, let’s construct it by simply passing some default values to the construct_block method.
I gave both proof_no and prev_hash a value of zero, although you can provide any value you want.
def construct_genesis(self): self.construct_block(proof_no=0, prev_hash=0) def construct_block(self, proof_no, prev_hash): block = Block( index=len(self.chain), proof_no=proof_no, prev_hash=prev_hash, data=self.current_data) self.current_data = [] self.chain.append(block) return block
c. Constructing new blocks
The construct_block method is used for creating new blocks in the blockchain.
Here is what is taking place with the various attributes of this method:
d. Checking validity
The check_validity method is important in assessing the integrity of the blockchain and ensuring anomalies are absent.
As mentioned earlier, hashes are essential for the security of the blockchain as even the slightest change in the object will lead to the generation of a completely new hash.
Therefore, this check_validity method uses if statements to check whether the hash of every block is correct.
It also verifies if every block points to the right previous block, through comparing the value of their hashes. If everything is correct, it returns true; otherwise, it returns false.
u/staticmethod def check_validity(block, prev_block): if prev_block.index + 1 != block.index: return False elif prev_block.calculate_hash != block.prev_hash: return False elif not BlockChain.verifying_proof(block.proof_no, prev_block.proof_no): return False elif block.timestamp <= prev_block.timestamp: return False return True
e. Adding data of transactions
The new_data method is used for adding the data of transactions to a block. It’s a very simple method: it accepts three parameters (sender’s details, receiver’s details, and quantity) and append the transaction data to self.current_data list.
Anytime a new block is created, this list is allocated to that block and reset once more as explained in the construct_block method.
Once the transaction data has been added to the list, the index of the next block to be created is returned.
This index is calculated by adding 1 to the index of the current block (which is the last in the blockchain). The data will assist a user in submitting the transaction in future.
def new_data(self, sender, recipient, quantity): self.current_data.append({ ‘sender’: sender, ‘recipient’: recipient, ‘quantity’: quantity }) return True
f. Adding proof of work
Proof of work is a concept that prevents the blockchain from abuse. Simply, its objective is to identify a number that solves a problem after a certain amount of computing work is done.
If the difficulty level of identifying the number is high, it discourages spamming and tampering with the blockchain.
In this case, we’ll use a simple algorithm that discourages people from mining blocks or creating blocks easily.
u/staticmethod def proof_of_work(last_proof): ”’this simple algorithm identifies a number f’ such that hash(ff’) contain 4 leading zeroes f is the previous f’ f’ is the new proof ”’ proof_no = 0 while BlockChain.verifying_proof(proof_no, last_proof) is False: proof_no += 1 return proof_no u/staticmethod def verifying_proof(last_proof, proof): #verifying the proof: does hash(last_proof, proof) contain 4 leading zeroes? guess = f'{last_proof}{proof}’.encode() guess_hash = hashlib.sha256(guess).hexdigest() return guess_hash[:4] == “0000”
g. Getting the last block
Lastly, the latest_block method is a helper method that assists in obtaining the last block in the blockchain. Remember that the last block is actually the current block in the chain.
u/property def latest_block(self): return self.chain[-1]
Let’s sum everything together
Here is the entire code for creating the fccCoin cryptocurrency.
You can also get the code on this GitHub repository.
import hashlib import time class Block: def __init__(self, index, proof_no, prev_hash, data, timestamp=None): self.index = index self.proof_no = proof_no self.prev_hash = prev_hash self.data = data self.timestamp = timestamp or time.time() u/property def calculate_hash(self): block_of_string = “{}{}{}{}{}”.format(self.index, self.proof_no, self.prev_hash, self.data, self.timestamp) return hashlib.sha256(block_of_string.encode()).hexdigest() def __repr__(self): return “{} – {} – {} – {} – {}”.format(self.index, self.proof_no, self.prev_hash, self.data, self.timestamp) class BlockChain: def __init__(self): self.chain = [] self.current_data = [] self.nodes = set() self.construct_genesis() def construct_genesis(self): self.construct_block(proof_no=0, prev_hash=0) def construct_block(self, proof_no, prev_hash): block = Block( index=len(self.chain), proof_no=proof_no, prev_hash=prev_hash, data=self.current_data) self.current_data = [] self.chain.append(block) return block u/staticmethod def check_validity(block, prev_block): if prev_block.index + 1 != block.index: return False elif prev_block.calculate_hash != block.prev_hash: return False elif not BlockChain.verifying_proof(block.proof_no, prev_block.proof_no): return False elif block.timestamp <= prev_block.timestamp: return False return True def new_data(self, sender, recipient, quantity): self.current_data.append({ ‘sender’: sender, ‘recipient’: recipient, ‘quantity’: quantity }) return True u/staticmethod def proof_of_work(last_proof): ”’this simple algorithm identifies a number f’ such that hash(ff’) contain 4 leading zeroes f is the previous f’ f’ is the new proof ”’ proof_no = 0 while BlockChain.verifying_proof(proof_no, last_proof) is False: proof_no += 1 return proof_no u/staticmethod def verifying_proof(last_proof, proof): #verifying the proof: does hash(last_proof, proof) contain 4 leading zeroes? guess = f'{last_proof}{proof}’.encode() guess_hash = hashlib.sha256(guess).hexdigest() return guess_hash[:4] == “0000” u/property def latest_block(self): return self.chain[-1] def block_mining(self, details_miner): self.new_data( sender=”0″, #it implies that this node has created a new block receiver=details_miner, quantity= 1, #creating a new block (or identifying the proof number) is awarded with 1 ) last_block = self.latest_block last_proof_no = last_block.proof_no proof_no = self.proof_of_work(last_proof_no) last_hash = last_block.calculate_hash block = self.construct_block(proof_no, last_hash) return vars(block) def create_node(self, address): self.nodes.add(address) return True u/staticmethod def obtain_block_object(block_data): #obtains block object from the block data return Block( block_data[‘index’], block_data[‘proof_no’], block_data[‘prev_hash’], block_data[‘data’], timestamp=block_data[‘timestamp’])
Now, let’s test our code to see if it works.
blockchain = BlockChain() print(“***Mining fccCoin about to start***”) print(blockchain.chain) last_block = blockchain.latest_block last_proof_no = last_block.proof_no proof_no = blockchain.proof_of_work(last_proof_no) blockchain.new_data( sender=”0″, #it implies that this node has created a new block recipient=”Quincy Larson”, #let’s send Quincy some coins! quantity= 1, #creating a new block (or identifying the proof number) is awarded with 1 ) last_hash = last_block.calculate_hash block = blockchain.construct_block(proof_no, last_hash) print(“***Mining fccCoin has been successful***”) print(blockchain.chain)
It worked!
Here is the output of the mining process:
***Mining fccCoin about to start*** [0 – 0 – 0 – [] – 1566930640.2707076] ***Mining fccCoin has been successful*** [0 – 0 – 0 – [] – 1566930640.2707076, 1 – 88914 – a8d45cb77cddeac750a9439d629f394da442672e56edfe05827b5e41f4ba0138 – [{‘sender’: ‘0’, ‘recipient’: ‘Quincy Larson’, ‘quantity’: 1}] – 1566930640.5363243]
Conclusion
There you have it!
That’s how you could create your own blockchain using Python.
Let me say that this tutorial just demonstrates the basic concepts for getting your feet wet in the innovative blockchain technology.
If this coin were deployed as-is, it could not meet the present market demands for a stable, secure, and easy-to-use cryptocurrency.
Therefore, it can still be improved by adding additional features to enhance its capabilities for mining and sending financial transactions.
Nonetheless, it’s a good starting point if you decide to make your name known in the amazing world of cryptos.
If you have any comments or questions, please post them below.
Happy (crypto) coding!
Source: Cryptoors
submitted by djkloud to CryptoTechnology [link] [comments]

Comprehensive List of Information Proton Technologies AG Can Send to Law Enforcement

Does Proton Technologies AG (or associated companies in order to provide service) have a comprehensive list of data that they could send to law enforcement in cases were a request is legitimate? Can a rep of Proton Technologies AG please respond? If anybody else has access to this list, can you please post the information? I am not looking for "guesses" on what they could send, thank you.
I have also put in a support request for this information. It will be interesting to see how they respond. :-)
Edit: So I guess I will curate a preliminary list myself. I will attempt to add to it over time, and may make a new post later on. If there are errors here, please let me know and I can make adjustments. Looks like mods at ProtonVPN removed a copy of this post in that subreddit. Only conclusion one can draw from this is that they dont want informed VPN users. I also posted a link to this in privacy as well, to demonstrate censorship by Proton Technologies AG. Stay frosty people!
submitted by CleverRubrik to ProtonMail [link] [comments]

Bitcoin Witness: use the worlds most secure, immutable, and decentralised public database to attest to the integrity of your files

About me

I have only ever done basic web development before but over the last 4-6 months i have been spending my time learning javascript, vuejs and a few blockchain technologies. I have finally finished the first release of Bitcoin Witness. I am aware that similar services already exist but my focus has been on simplifying the user experience and also making it scalable and free for anyone to use. Below provides more info on the app. I would love your feedback on the app and ideas / suggestions for me to take into the roadmap.

About Bitcoin Witness

https://bitcoinwitness.com is a free service that allows you to take any file and have its fingerprint witnessed in a bitcoin transaction. The service then allows you to download a proof file that can be used as verifiable evidence that your files fingerprint matches the fingerprint witnessed in the bitcoin transaction. The verification can be done using open source software even if our website does not exist in the future.

Protecting your data

We do not store your files data, in fact your files data is never even sent to our servers. Instead, your file is analysed locally in the browser to generate a SHA256 hash which is your files fingerprint.
The only data we do store is the file name, the fingerprint (hash), and the proof file generated by the app. This is so you can access and download proofs in the future. Anyone can retrieve the proof by presenting the original file at any time.
As you witness files, their fingerprint is also stored in your local cache so that you can easily retrieve the proof files when you load bitcoin witness on that device. It is recommend you download the proof once they are available to remove any reliance on our service.

How it works

Bitcoin Witness uses the Chainpoint protocol for many of its operations. Chainpoint is a layer two decentralised network that runs atop of (and supports the scaling of) bitcoin. Currently there are ~6500 community run Chainpoint nodes. Chainpoint nodes receive hashes and aggregate them together in a Merkle tree. The root of this tree is then included in a bitcoin transaction.
Your files fingerprint becomes part of a tree that is initially secured and witnessed in a Chainpoint calendar block (a decentralised database maintained by Chainpoint nodes) before being witnessed in a bitcoin transaction (the most secure decentralised database in the world).

Steps performed to witness your file

The end to end process for witnessing your file and retrieving a downloadable proof takes around ~90 minutes. This is because we wait for 6 bitcoin block confirmations before the proof file is made available.
The steps to witness files is as follows:
1. Generate the files fingerprint
When you select a file it is processed locally in the browser using the SHA256 algorithm to generate its fingerprint. We call it a fingerprint because if the same file is processed using this algorithm in the future, it will always result in the same hash value (fingerprint). If any modifications are made to your file it will result in a completely different hash value.
2. Combine the files fingerprint with entropy from NIST
The National Institute of Standards and Technology (NIST) randomness beacon generates full entropy bit strings and posts them in blocks every minute. The published values include a cryptographic link to all previous values to prevent retroactive changes.
Your files fingerprint is hashed with this random value to prove that the file was witnessed after that random value was generated.
3. Witness the file in the Chainpoint calendar
Chainpoint nodes aggregate your hash with other hashes in the network to create a Merkle tree and generate partial proof.
After ~ 12 seconds we retrieve a proof which includes the NIST value, timestamp information and the other hashes in the tree required to verify your files fingerprint in the anchor hash of a Chainpoint Calendar Block.
4. Witness the file in the bitcoin blockchain
The anchoring hash of the calendar block is then sent in the OP_RETURN of a Bitcoin transaction. As a result, this value is included in the raw transaction body, allowing the transaction ID and the Merkle path from that transaction to the Bitcoin block’s Merkle root to be calculated.
After 6 confirmations (~60 minutes) the final proof file is made available which contains all the Merkle path information required to verify your proof.

Steps to verify a file was witnessed by Bitcoin

The easiest way to verify a file has been witnessed is to visit https://bitcoinwitness.com and upload the proof file or the original file. Bitcoin Witness performs the verification processes and returns the relevant information about when the file was witnessed.
With that said, the benefit of the service is that even if the bitcoin witness app does not exist in the future. People must still be able to verify the files integrity (don’t trust us, trust bitcoin).
There are 2 steps to verify that your file was witnessed. The steps seek to verify that both your original file, and the downloaded proof file, have not been modified since the time of the bitcoin transaction / block. These steps are outlined below and can be performed using open source software.
1. Verify your file has not been modified
Generate a Sha256 hash of your file and check that the hash value generated matches the “hash” value in the proof file you are about to verify.
There are plenty of free online tools available that allow you to generate a hash of your file. And you can check the “hash” value in the proof file by opening it in a text editor.
2. Verify the proof file has not been modified
Re-run the operations set out in the proof file and then validate that the hash value produced at the end of the operations matches the Merkle root value in the bitcoin block.
The Chainpoint Parse library is open source software that can be used to re-run the operations in the proof file. The result can be verified to match the bitcoin Merkle root using any block explorer.

Future Vision and Roadmap

Today marks the release of the first version of the bitcoin witness app which can be found at https://bitcoinwitness.com. The immediate focus is on some additional features some users have already suggested
The broader vision and road map for bitcoin witness is to remove the need to trust organisations and each other with our data and instead trust bitcoin. We want to enable a world where people can make claims about data and that bitcoin’s immutable ledger can be used to verify that claim. The current version allows people to claim “This data has not been modified since that point in time”. An example of a future claim might be; “I was in possession of this data at that point in time”

Support us and get involved

This has been a fun learning experience. Would love it if you could all test out the app and give me feedback on the app, the user experience, any roadmap items I should think about. I welcome any comments here or join our telegram
For regular updates you can follow our twitter.
submitted by gaskills to Bitcoin [link] [comments]

Blockchain In Food Industry – A Quick Look At The Innovative Idea

Blockchain In Food Industry – A Quick Look At The Innovative Idea

https://preview.redd.it/xmg3j3sd62d41.jpg?width=1021&format=pjpg&auto=webp&s=fa8b110fff92cb4401a54433498a569bda1d4a61
Blockchain is a term heard by most of us – thanks to the cryptocurrency, particularly, Bitcoin. However, the general perception about the blockchain is that of a technology related to fintech only. Nonetheless, little do we know that blockchain isn’t applicable only to fintech, but also bears great potential for improvising other niches as well. For instance, the use of blockchain in food industry can significantly help manufacturers in enhancing food safety and quality.
In this article, we take a quick look at how applying blockchain can improvise in food manufacturing and packaging.

What Is Blockchain Technology?

Blockchain is distributed immutable ledger that stores data in various ‘blocks’ that cryptographically link together. The chain or the network includes multiple nodes that validate the database since each of them has a copy of complete data. The chain grows when the nodes verify a transaction in the new block. This eventually prevents ‘double-spending’ (with regard to fintech), or, any deliberate change or alteration to the data. If a change is necessary, then it is only possible after altering all other blocks. After verification, the new block gets linked with the growing and seemingly never-ending chain.
Despite being somewhat complex, blockchain technology allows noteworthy accountability. Since the entire data ever written exists on the chain, it becomes quite easy for anyone to trace back any changes.
https://preview.redd.it/b1a3yc4h62d41.png?width=982&format=png&auto=webp&s=1b186132079145ab1e8eac25b2e47b17d0166797
In simple words, the technology involves numerous computers linked on a network, where each computer plays its role to verify a transaction. This offers transparency of data to every user on the network, and hence, better traceability with improved data security.

Benefits Of Using Blockchain In Food Industry

Though, blockchain seems quite unrelated to the food industry. However, the thing that makes it most relevant to this niche is its tremendous accountability.
One of the biggest problems the food industries are tackling is food wastage. From the production through the entire supply chain, numerous factors contribute to increasing food waste. Though, the industrialists are employing various means to reduce food waste. Yet, they have not been entirely successful yet owing to poor traceability.
This is where the blockchain can play its role. If the industries begin leveraging blockchain to improve food supply chain traceability, they can eventually identify the areas that cause wastage.
For better understanding, here we list some ways through which applying blockchain in food industry can help improve processes.

Blockchain And Food Security

Using blockchain in food industries can help prevent food recalls. Using this technology, not only the industries can identify food spoilage spots, but can also detect how an incident happened.
Since blockchain technology keeps a good record of processes with timestamps, one can easily trace back the exact events, from production to packaging, transportation, and delivery, with all related details such as the equipment involved, the vehicle, as well as the drivers’ details.
Likewise, food makers can also create separate blocks for food ingredients as well as for the storage at the warehouse.
Some of the companies employing food blockchain solutions include Nestle, Walmart, and Unilever.
Related: 5 Ways Food Processing Industries Can Reduce Food Waste

Fraud Prevention

Better traceability is the key to prevent frauds and fraudulent activities. The same applies to the food industry as well.
Whether it is about any adulteration, illegal activity, or fraud, blockchain can detect it all. Any food that does not meet the originality criteria will face ejection by the blockchain, even when the product is in the supply chain.
This will not only help the industries in identifying problem areas. Rather, it also saves the firms’ reputation by preventing recalls or minimizing the chances of complaints from the consumers’ end.

Transparency For The Consumers

The consumers of this era are much more health-conscious than ever before. They have better awareness about the health problems, ethical and moral issues arising from consuming wrong foods. That is why they demand transparency and availability of comprehensive details about the product they consume.
With blockchain, companies get a chance to establish themselves as credible brands among consumers. With the instant availability of precise details, such as ingredients, accurate dates of manufacturing and expiry, GMO/non-GMO labelling, the consumers can make better decisions about the choice of food.
Moreover, it also lets them realise the transparency of the manufacturers, which eventually builds their trust in the brand.

Wrapping It All

Using blockchain in food industry is an innovative idea that allows streamlining operations with better traceability. Through blockchain, not only the industries can reduce food waste, but can also win consumers’ trust. Though, the key players of the food industry have already adopted this technology for improving processes. Still, the technology awaits full exploitation of its potential. Perhaps, spreading awareness about blockchain among the industrialists can contribute to an increased adaptation of this technology for food safety.
Related: Breakthrough Technologies In Food Processing That We Look Up To In 2020
This article first appeared at: https://samuel-lison.blog/blockchain-in-food-industry-a-quick-look-at-the-innovative-idea/
submitted by SamuelMLLison to u/SamuelMLLison [link] [comments]

The fungibility of Nano - is it an issue?

In a recent video (link includes timestamp) by Andreas M. Antonopoulos he gets asked to play "devils advocate", and expose some of the vulnerabilities of BitCoin that can be exploited by banks and governments to throw the system out of balance.
Antonopoulos mentions that the base-layer blockchain of BitCoin does not have sufficient privacy/anonymity functionality. He then goes on to explain how this effects the coins fungibility, and thus how "dirty BitCoins" becomes less valuable than "fresh BitCoins" straight from a new block. This is bad, because it affects the coins fungibility, which is an essential function for money.My question/concern, what is Nano doing to combat an issue like the one described in the video? Is this cause for concern, or are crypto-currencies redefining the way money works in such a way that this issue is irrelevant somehow? I'm not an economist, so I have quite a limited understanding of these things thus why I'm asking you all for opinions/knowledge/insight :-)
EDIT: Wow, lots of response in here, thanks a lot everyone for sharing your opinions/knowledge/insight!
submitted by BloodaxeNOR to nanocurrency [link] [comments]

AMA: Ask Mike Anything

Hello again. It's been a while.
People have been emailing me about once a week or so for the last year to ask if I'm coming back to Bitcoin now that Bitcoin Cash exists. And a couple of weeks ago I was summoned on a thread called "Ask Mike Hearn Anything", but that was nothing to do with me and I was on holiday in Japan at the time. So I figured I should just answer all the different questions and answers in one place rather than keep doing it individually over email.
Firstly, thanks for the kind words on this sub. I don't take part anymore but I still visit occasionally to see what people are talking about, and the people posting nice messages is a pleasant change from three years ago.
Secondly, who am I? Some new Bitcoiners might not know.
I am Satoshi.
Just kidding. I'm not Satoshi. I was a Bitcoin developer for about five years, from 2010-2015. I was also one of the first Bitcoin users, sending my first coins in April 2009 (to SN), about 4 months after the genesis block. I worked on various things:
You can see a trend here - I was always interested in developing peer to peer decentralised applications that used Bitcoin.
But what I'm best known for is my role in the block size debate/civil war, documented by Nathaniel Popper in the New York Times. I spent most of 2015 writing extensively about why various proposals from the small-block/Blockstream faction weren't going to work (e.g. on replace by fee, lightning network, what would occur if no hard fork happened, soft forks, scaling conferences etc). After Blockstream successfully took over Bitcoin Core and expelled anyone who opposed them, Gavin and I forked Bitcoin Core to create Bitcoin XT, the first alternative node implementation to gain any serious usage. The creation of XT led to the imposition of censorship across all Bitcoin discussion forums and news outlets, resulted in the creation of this sub, and Core supporters paid a botnet operator to force XT nodes offline with DDoS attacks. They also convinced the miners and wider community to do nothing for years, resulting in the eventual overload of the main network.
I left the project at the start of 2016, documenting my reasons and what I expected to happen in my final essay on Bitcoin in which I said I considered it a failed experiment. Along with the article in the New York Times this pierced the censorship, made the wider world aware of what was going on, and thus my last gift to the community was a 20% drop in price (it soon recovered).

The last two years

Left Bitcoin ... but not decentralisation. After all that went down I started a new project called Corda. You can think of Corda as Bitcoin++, but modified for industrial use cases where a decentralised p2p database is more immediately useful than a new coin.
Corda incorporates many ideas I had back when I was working on Bitcoin but couldn't implement due to lack of time, resources, because of ideological wars or because they were too technically radical for the community. So even though it's doesn't provide a new cryptocurrency out of the box, it might be interesting for the Bitcoin Cash community to study anyway. By resigning myself to Bitcoin's fate and joining R3 I could go back to the drawing board and design with a lot more freedom, creating something inspired by Bitcoin's protocol but incorporating all the experience we gained writing Bitcoin apps over the years.
The most common question I'm asked is whether I'd come back and work on Bitcoin again. The obvious followup question is - come back and work on what? If you want to see some of the ideas I'd have been exploring if things had worked out differently, go read the Corda tech white paper. Here's a few of the things it might be worth asking about:
I don't plan on returning to Bitcoin but if you'd like to know what sort of things I'd have been researching or doing, ask about these things.
edit: Richard pointed out some essays he wrote that might be useful, Enterprise blockchains for cryptocurrency experts and New to Corda? Start here!
submitted by mike_hearn to btc [link] [comments]

An in-depth look at what happens when you undermine utility.

I want to fully analyze the talking point that "Bitcoin is a store of value," because it's one that I see very frequently and people have different views on how the value of an asset is generated.
This one is also fun because I get to put on my Economist hat instead of my Computer Engineering hat which has always been a strong secondary interest of mine.
Please buckle in, because this is a longer read, but if you have any doubts about how value is generated, I really think it's a worthwhile one.
Other Assets that Bitcoin is Frequently Compared To
I'm going to (mostly) skip some of the more common comparisons of cryptocurrency to (Beanie Babies, Tulips, Pets.com, etc.).
I'll only briefly address it here in saying: Beanie Babies are a poor comparison because they had only had perceived scarcity in the way they were distributed so they were heavily undermined from the supply side. Tulips have a debatable history in general as far as the magnitude of purchase, and even if that history is fully accurate, their utility was only really derived from a brief social fad... not a continuing stable utility. Lastly, Pets.com is closer to being apt, except that they arguably had no major utility from the start in that it was (almost) always more expensive and slower to order through their service as opposed to going to the local pet store.
The Basis of the "Store of Value Argument
So the main argument of "Bitcoin [being] a store of value" is rooted in Bitcoin being scarce... with utility not playing a major role. The counterpoint against this view is that it takes both scarcity and utility to give a premium value to a good or service.
So let's try to separate out the two factors.
We'll first look at a good that has premium value due to both utility and scarcity where neither factor has been undermined.
Utility Plus Scarcity
We'll start by taking a look at a good that has both utility and scarcity. I think the one thing in the world that best exemplifies this status, (and my friends over at /magicTCG can attest,) is the Black Lotus. This is the mack-daddy of all Magic cards and as of this year, a mint condition version from the earliest set can fetch a six digit price point.
First, let's talk about the Lotus' scarcity: Wizards of the Coast has a strict reprint policy where no card functionally identical to the Black Lotus may be reprinted. That means with the rare exception of an undetected fake, the pool of Black Lotuses will never get larger, and in the case of damage or destruction, will certainly get smaller.
Next we'll talk about the Lotus' utility: As arguably the most impactful card in the game, anyone wanting to play Vintage format on a competitive level absolutely needs to have a Black Lotus as well as (almost) every other power-nine card. If you want to see people still playing with pieces of cardboard worth over $10,000+ each, you absolutely can. Even though these cards have utility for only a select few and the price outpaces their direct value-earning potential, the fact that they also have maintained utility means that someone will very likely be willing to purchase this card down the road at the same or higher price than the person that owns it now. Because utility is maintained, the value will continually increase.
I'm not saying this price rise will continue forever though; Something could happen to undermine the utility or scarcity of MTG cards. The pool of people playing Vintage, or MTG at all could shrink, Undetectable counterfeits could surface, WotC could suddenly change the reprint policy. Etc.
In fact, if you would like further information about the Black Lotus from an economic standpoint, I recommend listening to the Planet Money episode: The Curse of the Black Lotus
Scarcity with Shrinking Utility
What about a good that is still just as scarce as it ever was, but has experienced a reduction in utility?
The best example of this phenomenon is probably the New York Taxi Medallion. Taxi Medallions were first introduced around the great depression where less than 12,000 were made. That number has increased to somewhere in the mid 13,000 range today. Regardless, this is clearly a scarce commodity - especially with the extreme growth of NYC itself and thus, the increased demand for cabs. NYC enforced the medallion law relatively strictly for many years, but the introduction of Uber and Lyft also came with less enforcement of the Medallion law. That has caused the value to plummet. I strongly recommend two podcasts that deal with this exact topic:
The first is another Planet Money episode: "The Taxi King"
The second is a New York Times Daily titled "The Taxi Driver's Plight"
If you don't want to listen to the entirety of each episode, I think the most poignant take-away is in the Planet Money episode at timestamp 13:40:
"You can understand where the banks are coming from, they were lending Friedman money based on the rarity of the Taxi Medallions. Those precious taxi medallions. But now, if you can operate something that works pretty much exactly like a taxi without a medallion, the banks are figuring that these medallions are not worth as much as they used to be."
The banks absolutely understand that even though the rarity has not changed at all, their value is based quite heavily on their utility. With less utility comes less demand, and the price has, in response, suffered greatly.
In fact, in the update to that podcast, they note that the price of a taxi medallion is now below $200,000 and they not it doesn't look like things will be better anytime soon.
Value Requires Both Utility and Scarcity
It is pretty clear that value is not based upon scarcity alone.
I hope that users entering this space take a long look at what each cryptocurrency they are buying is useful for.
Cryptocurrencies that do the best job of maximizing their utility while remaining relatively scarce will do quite well. Cryptocurrencies that don't increase or expand their utility will certainly have their value proposition undermined.
TL;DR: Value clearly comes from both utility and scarcity. Invest responsibly.
Edit - ty for the gold, it's much appreciated. From here on out I would prefer tips as I am attempting to spur crypto adoption in my community. Now that BCH has good PoS solutions, it's great to have demo / tiny giveaway balances.
submitted by CaptainPatent to btc [link] [comments]

It's finally here! Tautulli v2 [beta] (formerly PlexPy v2)

It's finally here! Tautulli v2 [beta] (formerly PlexPy v2).

The long awaited for PlexPy v2 is finally here with a new name Tautulli! Also check us out on the new Plex Labs!
I'm looking for some brave people to help me test some new feature before I fully release them. It's a very big update so I want to make sure everything is working.
Warning: This may mess up your PlexPy install and/or your database. You have been warned. Only join the beta if you are serious about testing and reporting bugs, otherwise I strongly recommend you wait until the final release.

Changelog

v2.0.0-beta (2017-12-18)

v2.0.1-beta (2017-12-19)

v2.0.2-beta (2017-12-24)

v2.0.3-beta (2017-12-25)

v2.0.4-beta (2017-12-29)

v2.0.5-beta (2017-12-31)

v2.0.6-beta (2017-12-31)

v2.0.7-beta (2018-01-01)

v2.0.8-beta (2018-01-03)

v2.0.9-beta (2018-01-03)

v2.0.10-beta (2018-01-04)

v2.0.11-beta (2018-01-05)

v2.0.12-beta (2018-01-07)

v2.0.13-beta (2018-01-13)

v2.0.14-beta (2018-01-20)

v2.0.15-beta (2018-01-27)

v2.0.16-beta (2018-01-30)

v2.0.17-beta (2018-02-03)

v2.0.18-beta (2018-02-12)

v2.0.19-beta (2018-02-16)

v2.0.20-beta (2018-02-24)

v2.0.21-beta (2018-03-04)

v2.0.22-beta (2018-03-09)

"I'm interested! Where do I sign up?"

Assuming you already have PlexPy installed using git, all you need to do is follow these steps:
  1. Backup your database! Go to the PlexPy Settings > General tab > Backup Database. You will need to restore this if something messes up. I'm not helping you if you mess up your database and you didn't create a backup.
  2. Shut down PlexPy by going to Settings > Shutdown.
  3. Using your shell/command line, run the following from the PlexPy folder:
    git fetch git checkout beta 
  4. Start Tautulli as normal.
  5. Post below if you find any bugs (include logs). Please don't post on GitHub issues or the Plex forum thread with bugs/issues from the beta test. If you do, I will laugh at you and delete your post.
    • Please read the issues guidelines before report any problems, and refer to the FAQ for common issues.
    • New features can be submitted on FeatHub (use the search to see if it has already been requested). Please read the feature request guidelines before requesting new features.
    • Join the Discord Server chat for faster help and general chit chat. (Note: the Gitter chat is no longer being used.)
If you want to revert back to the version of PlexPy before beta testing:
Warning: You will not be able to use your v2 database with v1!
  1. Shut down Tautulli by going to Settings > Shutdown.
  2. Restore your backed up plexpy.db file (it can be found in the backup folder).
  3. Using your shell/command line, run the following from the PlexPy folder:
    git checkout master 
  4. Start PlexPy as normal.
Buy me a coffee if you want to support the project! - PayPal | Bitcoin: 3FdfJAyNWU15Sf11U9FTgPHuP1hPz32eEN

Answers to your questions:

  • Why did you call it Tautulli?
    • Because it sounds cool and means "to watch or monitor" in Inuktitut.
  • I don't like the new name!
    • That's too bad. Also, that is not a question.
  • When will v2 be out of beta?
    • When I feel like there are no more major bugs with it. SoonTM.
  • Is there an iOS app?
    • No, there isn't. It costs money to be an iOS developer.
submitted by SwiftPanda16 to PleX [link] [comments]

Ethereum's future is bright, the DApps are coming!

The DApps are coming, the DApps are coming!

Chin up boys and girls – the DApps (Decentralized Apps) are finally coming. Utility, not speculation/manipulation/shilling etc., is what, in the end, will give/justify the value of blockchains.
 
Of the top 100 tokens, 91 of them are on the Ethereum blockchain (ERC-20). The most valuable non-Ethereum tokens by market cap are USDT (4) and GAS (25). Eventually, ICX (6), VeChain (3) and EOS (1) and several others will be migrating to their own blockchains. Still, this leaves Ethereum with an overwhelming market dominance for tokens (aka DApps) and Ethereum has been clearly recognized as the blockchain to launch ICOs/DApps.
 
We have already seen several DApps successfully launch on mainnet including CrytptoKitties, Crypto Sportz, Edgeless, Etherbots, Ethercraft, Etheremon, Etheroll, ETHLend, Forkdelta (RIP Etherdelta), 0xBitcoin and Ethlance among others. Check out a whole list on DappRadar and track the progress of some lesser known, smaller projects on StateoftheDApps (Note: I cannot vouch for all of these DApps. There have been and always will be scammers in the crypto space. Please, always do your own research!)
 
For the rest of March + Q2 (April - June) we are going see the biggest implementation of DApps on the Ethereum mainnet to date. Below I’ve laid out, in alphabetical order and in varying detail, what’s happening between now and the end of Q2 of this year. (I’ve also added some info, where especially relevant, of big stuff coming after Q2). I hope any biases I may have do not come through too much in the writing.
 
To hammer home on utility once more: One year ago today, the daily transaction count was at 57,000. Yesterday, the network confirmed over 752,000 transactions (a 13x increase) (And remember, ATH in January was 1.349 million txns!) [Source]
 

On to the DApps:

 
Airswap
Subreddit
 
Aragon
Subreddit
 
Augur
Subreddit
 
BlockCAT
Subreddit
 
Digix
Subreddit
 
Ethorse
Subreddit
 
FunFair
Subreddit
 
FundRequest
Subreddit
 
Giveth
Wiki
 
Golem
Subreddit
 
iExec
Subreddit
 
Kyber
Subreddit
 
MakerDAO
Subreddit
This project can take a little time to understand, so here's a thorough ELIM5 walkthrough.
 
Melonport
Subreddit
 
OmiseGO
Subreddit
 
Request
Subreddit
 
Spankchain
Subreddit
 
status.im
Subreddit
 
Streamr
Subreddit
 
The 0x Protocol
Subreddit
 
Also, an informative article about some of the differences between the various decentralized exchange protocols here.
 
Some general Ethereum news to be excited about:
 
  • Vitalik recently hinted, in a since deleted tweet, that the sharding testnet will be coming online in the near future (I think Q2 isn’t too early a guess).
    • What is sharding? Sharding is where the entire state of the network is split into a bunch of partitions called shards that contain their own independent piece of state and transaction history. In this system, certain nodes would process transactions only for certain shards, allowing the throughput of transactions processed in total across all shards to be much higher than having a single shard do all the work as the mainchain does now. [Source]
 
  • Alpha Casper FFG testnet has been successfully running since Dec. 31, 2017.
    • What is Casper? Casper FFG aka Vitalik’s Casper is a hybrid POW/POS consensus mechanism. This is the version of Casper that is going to be implemented first. In a Proof of Stake system, validators stake a portion of their Ethers and start validating blocks. Meaning, when they discover a block which they think can be added to the chain, they will validate it by placing a bet on it. [Source]
 
(To stay up-to-date on Ethereum research development, check out Ethresear.ch)
 
  • The Ethereum Community Conference (EthCC) is March 8-10 in Paris. Talks will focus around “scalability, anonymity, development tools, governance compliance” among other topics.
    • Speakers include representatives from the Ethereum Foundation, Ledger, Metamask, Shapeshift, Oraclize, Uport, Web3Foundation, Melonport, ConsenSys, JP Morgan, Coinbase – Toshi, Parity, SpankChain, FunFair, Aragon, AirSwap, EEA, IExec, Cosmos, OmiseGO, Circle, Gnosis, among others.
    • UPDATE: EthCC was a resounding success! If you missed it or want to re-watch any of the talks, check out this handy thread of videos, painstakingly culled and timestamped by u/alsomahler.
  • The Ethereum Developer Conference (EDCON) is May 3-5 in Toronto. This will be the biggest ETH dev conference since DEVCON 3 last November. The agenda is still being worked out, but speakers include representatives from the Ethereum Foundation, Polkadot, Parity, Plasma, OmiseGO, Cosmos, Tendermint, Giveth, Maker, Gnosis, and many others.
  • The Enterprise Ethereum Foundation (EEF) just keeps growing and growing and growing.
 

More, because I just can’t stop:

  • MetaMask recently passed 1 million installs!
  • 5.6 billion requests per day for Infura.io (Decentralized web3 infrastructure)
  • 280,000 downloads of TruffleSuit (ETH development framework)
    [Source]
 
  • ConsenSys has grown to over 600 employees in six major offices located around the world. I personally think ConsenSys is important (and awesome) because they are huge Ethereum evangelists and provide (in)valuable resources to help bring DApps come to life!
    • From their website: “The ConsenSys “hub” coordinates, incubates, accelerates and spawns “spoke” ventures through development, resource sharing, acquisitions, investments and the formation of joint ventures. These spokes benefit from foundational components built by ConsenSys that enable new services and business models to be built on the blockchain.”
    • Several of the projects I listed above are ConSensys formations including AirSwap and MetaMask.
 
Thanks for reading this far! Hopefully it wasn’t too exhausting of a read.
 
I am certain I have forgotten some DApps, so please feel free to comment/PM any and all suggestions/corrections to make this list more informative/inclusive/accurate and I will update it.
TL;DR
submitted by GetYourAssToPluto to ethtrader [link] [comments]

Part 6. (Last part) I'm writing a series about blockchain tech and possible future security risks. Failing shortcuts in an attempt to accomplish Quantum Resistance

The previous parts will give you usefull basic blockchain knowledge and insights on quantum resistance vs blockchain that are not explained in this part.
Part 1, what makes blockchain reliable?
Part 2, The mathematical concepts Hashing and Public key cryptography.
Part 3, Quantum resistant blockchain vs Quantum computing.
Part 4A, The advantages of quantum resistance from genesis block, A
Part 4B, The advantages of quantum resistance from genesis block, A
Part 5, Why BTC is vulnerable for quantum attacks sooner than you would think.

Failing shortcuts in an attempt to accomplish Quantum Resistance
Content:
Hashing public keys
“Instant” transactions
FIFO
Standardized fees
Multicast
Timestamped transactions
Change my mind: If a project doesn't use a Quantum Resistant signature scheme, it is not 100% Quantum Resistant.
Here are some of the claims regarding Quantum Resistance without the use of a quantum resistant signature scheme that I have come across so far. For every claim, I give arguments to substantiate why these claims are incorrect.
“We only have public keys in hashed form published. Even quantum computers can't reverse the Hash, so no one can use those public keys to derive the private key. That's why we are quantum resistant.” This is incorrect.
This example has been explained in the previous article. To summarize: Hashed public keys can be used as an address for deposits. Deposits do not need signature authentication. Alternatively, withdrawals do need signature authentication. To authenticate a signature, the public key will always need to be made public in full, original form. As a necessary requirement, the full public key would be needed to spend coins. Therefore the public key will be included in the transaction.
The most famous blockchain to use hashed public keys is Bitcoin. Transactions can be hijacked during the period a user sends a transaction from his or her device to the blockchain and the moment a transaction is confirmed. For example: during Bitcoins 10 minute blockchain, the full public keys can be obtained to find private keys and forge transactions. Page 8, point 3 Hashing public keys does have advantages: they are smaller than the original public keys. So it does save space on the blockchain. It doesn't give you Quantum Resistance however. That is a misconception.
“Besides having only hashed public keys on the blockchain, we also have instant transactions. So there is no time to hijack a transaction and to obtain the public key fast enough to forge a transaction. That's why we are quantum resistant.” This is incorrect and impossible.
There is no such thing as instant transactions. A zero second blocktime for example is a claim that can’t be made. Period. Furthermore, transactions are collected in pools before they are added to a block that is going to be processed. The time it takes for miners to add them to a new block before processing that block depends on the amount of transactions a blockchain needs to process at a certain moment. When a blockchain operates within its maximum capacity (the maximum amount of transactions that a blockchain can process per second), the adding of transactions from the pool will go quite swiftly, but still not instantaneously.
However, when there is high transaction density, transactions can be stuck in the pool for a while. During this period the transactions are published and the full public keys can be obtained. Just as with the previous hijacking example, a transaction can be forged in that period of time. It can be done when the blockchain functions normally, and whenever the maximum capacity is exceeded, the window of opportunity grows for hackers.
Besides the risk that rush hours would bring by extending the time to work with the public key and forge transactions, there are network based attacks that could serve the same purpose: slow the confirmation time and create a bigger window to forge transactions. These types are attacks where the attacker targets the network instead of the sender of the transaction: Performing a DDoS attack or BGP routing attack or NSA Quantum Insert attack on a peer-to-peer network would be hard. But when provided with an opportunity to earn billions, hackers would find a way.
For example: https://bitcoinmagazine.com/articles/researchers-explore-eclipse-attacks-ethereum-blockchain/
For BTC: https://eprint.iacr.org/2015/263.pdf
An eclipse attack is a network-level attack on a blockchain, where an attacker essentially takes control of the peer-to-peer network, obscuring a node’s view of the blockchain.
That is exactly the recipe for what you would need to create extra time to find public keys and derive private keys from them. Then you could sign transactions of your own and confirm them before the originals do.
This specific example seems to be fixed now, but it most definitely shows there is a risk of other variations to be created. Keep in mind, before this variation of attack was known, the common opinion was that it was impossible. With little incentive to create such an attack, it might take a while until another one is developed. But when the possession of full public keys equals the possibility to forge transactions, all of a sudden billions are at stake.
“Besides only using hashed public keys as addresses, we use the First In First Out (FIFO) mechanism. This solves the forged transaction issue, as they will not be confirmed before the original transactions. That's why we are quantum resistant.” This is incorrect.
There is another period where the public key is openly available: the moment where a transaction is sent from the users device to the nodes on the blockchain network. The sent transaction can be delayed or totally blocked from arriving to the blockchain network. While this happens the attacker can obtain the public key. This is a man-in-the-middle (MITM) attack. A MITM is an attack where the attacker secretly relays and possibly alters the communication between two parties who believe they are directly communicating with each other. No transaction is 100% safe from a MITM attack. This type of attack isn’t commonly known amongst average usergroups due to the fact communication is done either encrypted or by the use of private- public key cryptography. Therefore, at this point of time MITM attacks are not an issue, because the information in transactions is useless for hackers. To emphasize the point made: a MITM attack can be done at this point of time to your transactions. But the information obtained by a hacker is useless because he can not break the cryptography. The encryption and private- public key cryptography is safe at this point of time. ECDSA and RSA can not be broken yet. But in the era of quantum computers the problem is clear: an attacker can obtain the public key and create enough time to forge a transaction which will be sent to the blockchain and arrive there first without the network having any way of knowing the transaction is forged. By doing this before the transaction reaches the blockchain, FIFO will be useless. The original transaction will be delayed or blocked from reaching the blockchain. The forged transaction will be admitted to the network first. And First In First Out will actually help the forged transaction to be confirmed before the original.
“Besides having only hashed public keys, we use small standardized fees. Forged transactions will not be able to use higher fees to get prioritized and confirmed before the original transactions, thus when the forged transaction will try to confirm the address is already empty. This is why we are quantum resistant.” This is incorrect.
The same arguments apply as with the FIFO system. The attack can be done before the original transaction reaches the network. Thus the forged transaction will still be handled first no matter the fee hight.
“Besides the above, we use multicast so all nodes receive the transaction at the same time. That's why we are quantum resistant.” This is incorrect.
Multicast is useless against a MITM attack when the attacker is close enough to the source.
“Besides the above, we number all our transactions and authenticate nodes so the user always knows who he's talking to. That's why we are quantum resistant.” This is incorrect.
Besides the fact that you’re working towards a centralized system if only verified people can become nodes. And besides the fact that also verified nodes can go bad and work with hackers. (Which would be useless if quantum resistant signature schemes would be implemented because a node or a hacker would have no use for quantum resistant public keys and signatures.) There are various ways of impersonating either side of a communication channel. IP-spoofing, ARP-spoofing, DSN-spoofing etc. All a hacker needs is time and position. Time can be created in several ways as explained above. All the information in the transaction an original user sends is valid. When a transaction is hijacked and the communication between the user and the rest of the network is blocked, a hacker can copy that information to his own transaction while using a forged signature. The only real effective defense against MITM attacks can be done on router or server-side by a strong encryption between the client and the server (Which in this case would be quantum resistant encryption, but then again you could just as well use a quantum resistant signature scheme.), or you use server authentication but then you would need that to be quantum resistant too. There is no serious protection against MITM attacks when the encryption of the data and the authentication of a server can be broken by quantum computers.
Only quantum resistant signature schemes will secure blockchain to quantum hacks. Every blockchain will need their users to communicate their public key to the blockchain to authenticate signatures and make transactions. There will always be ways to obtain those keys while being communicated and to stretch the period where these keys can be used to forge transactions. Once you have, you can move funds to your own address, a bitcoin mixer, Monero, or some other privacy coin.
Conclusion
There is only one way to currently achieve Quantum Resistance: by making sure the public key can be made public without any risks, as is done now in the pre-quantum period and as Satoshi has designed blockchain. Thus by the use of quantum resistant signature schemes. The rest is all a patchwork of risk mitigation and delaying strategies; they make it slightly harder to obtain a public key and forge a transaction but not impossible.
Addition
And then there is quite often this strategy of postponing quantum resistant signature schemes
“Instead of ECDSA with 256 bit keys we will just use 384 bit keys. And after that 521 bit keys, and then RSA 4096 keys, so we will ride it out for a while. No worries we don’t need to think about quantum resistant signature schemes for a long time.” This is highly inefficient, and creates more problems than it solves.
Besides the fact that this doesn’t make a project quantum resistant, it is nothing but postponing the switch to quantum resistant signatures, it is not a solution. Going from 256 bit keys to 384 bit keys would mean a quantum computer with ~ 3484 qubits instead of ~ 2330 qubits could break the signature scheme. That is not even double and postpones the problem either half a year or one year, depending which estimate you take. (Doubling of qubits every year, or every two years). It does however have the same problems as a real solution and is just as much work. (Changing the code, upgrading the blockchain, finding consensus amongst the nodes, upgrading all supporting systems, hoping the exchanges all go along with the new upgrade and migrate their coins, heaving all users migrate their coins.) And then quite soon after that, they'll have to go at it again. What they will do next? Go for 512 bit curves? Same issues. It's just patchworks and just as much hassle, but then over and over again for every “upgrade” from 384 to 521 etc.
And every upgrade the signatures get bigger, and closer to the quantum resistant signature sizes and thus the advantage you have over blockchains with quantum resistant signature schemes gets smaller. While the quantum resistant blockchains are just steady going and their users aren’t bothered with all the hassle. At the same time the users of the blockchain that is constantly upgrading to a bigger key size, keep on needing to migrate their coins to the new and upgraded addresses to stay safe.
submitted by QRCollector to CryptoTechnology [link] [comments]

Bitcoin Protocol Explained - Timestamp Server / Global Ledger Blockchain 101 Ep 47 - What is a Timestamp? Linked timestamping - Video Learning - WizScience.com Bitcoin DROPS to Key Level... What Now? How to Timestamp a File with Bitcoin

Timestamp . Although the average time between Bitcoin blocks is 10 minutes, the timestamp of the next block is a full 6 days after the genesis block. One interpretation is that Satoshi was working on bitcoin for some time beforehand and the The Times front page prompted him to release it to the public. He then mined the genesis block with a A timestamp is accepted as valid if it is greater than the median timestamp of previous 11 blocks, and less than the network-adjusted time + 2 hours. "Network-adjusted time" is the median of the timestamps returned by all nodes connected to you. As a result, block timestamps are not exactly accurate, and they do not need to be. From Bitcoin Wiki. Jump to: navigation, search. Each block contains a Unix time timestamp. In addition to serving as a source of variation for the block hash, they also make it more difficult for an adversary to manipulate the block chain. A timestamp is accepted as valid if it is greater than the median timestamp of previous 11 blocks, and The timestamp would be returned in blocks[0].time. Note: Transactions technically can have an individual timestamp. When they do, it is the locktime property, see Bitcoin Wiki - Transaction. However, the locktime is most likely not going to be the time that it was created, rather, the time it is available for spending: A timestamp is accepted as valid if it is greater than the median timestamp of previous 11 blocks, and less than the network-adjusted time + 2 hours. "Network-adjusted time" is the median of the timestamps returned by all nodes connected to you.

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Bitcoin Protocol Explained - Timestamp Server / Global Ledger

Bitcoin drops to a key level on the charts - what could this mean? What are the next key support levels on the charts. We examine the facts. #Bitcoin #BTCUSD #AlessioRastani For membership: https ... Bitcoin Protocol Explained - Timestamp Server / Global Ledger - Duration: 2:57. sentdex 9,334 views. 2:57. Blockchain 101 Ep 47 - What is a Timestamp? - Duration: 0:59. In this short video, the Bitcoin timestamp server / global ledger is discussed. As usual, however, we present ourselves with an ending challenge which is to be covered in the, you guessed it, next ... Simply put, the timestamp proves when and what has happened on the blockchain, and it’s tamper-proof. Timestamp plays to role of a notary, and it’s more credible than a traditional one. Time-stamping, also called notarization, anchoring, 'proof-of-ownership' or 'proof-of-existence', with Bitcoin is fast, cheap and 100% reliable. The fee is currently around 4 cents (goes to ...

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