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Proof-of-space
Proof of space (PoS) is a type of consensus algorithm achieved by demonstrating one's legitimate interest in a service (such as sending an email) by allocating a non-trivial amount of memory or disk space to solve a challenge presented by the service provider. The concept was formulated in 2013 by Dziembowski ''et al.'' and (with a different formulation) by Ateniese ''et al.''. Proofs of space are very similar to proofs of work (PoW), except that instead of computation, storage is used to earn cryptocurrency. Proof-of-space is different from memory-hard functions in that the bottleneck is not in the number of memory access events, but in the amount of memory required. After the release of Bitcoin, alternatives to its PoW mining mechanism were researched, and PoS was studied in the context of cryptocurrencies. Proofs of space are seen as fairer and greener alternatives by blockchain enthusiasts due to the general-purpose nature of storage and the lower energy cost required by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proof Of Space
Proof of space (PoS) is a type of consensus algorithm achieved by demonstrating one's legitimate interest in a service (such as sending an email) by allocating a non-trivial amount of Computer memory, memory or disk space to solve a challenge presented by the service provider. The concept was formulated in 2013 by Dziembowski ''et al.'' and (with a different formulation) by Ateniese ''et al.''. Proofs of space are very similar to proof-of-work system, proofs of work (PoW), except that instead of computation, storage is used to earn cryptocurrency. Proof-of-space is different from memory-hard functions in that the Bottleneck (software), bottleneck is not in the number of memory access events, but in the amount of memory required. After the release of Bitcoin, alternatives to its PoW Cryptocurrency mining, mining mechanism were researched, and PoS was studied in the context of cryptocurrencies. Proofs of space are seen as fairer and Green computing, greener alternatives by blockch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Consensus Algorithm
A fundamental problem in distributed computing and multi-agent systems is to achieve overall system reliability in the presence of a number of faulty processes. This often requires coordinating processes to reach consensus, or agree on some data value that is needed during computation. Example applications of consensus include agreeing on what transactions to commit to a database in which order, state machine replication, and atomic broadcasts. Real-world applications often requiring consensus include cloud computing, clock synchronization, PageRank, opinion formation, Smart grid, smart power grids, state estimation, Unmanned aerial vehicle, control of UAVs (and multiple robots/agents in general), Load balancing (computing), load balancing, blockchain, and others. Problem description The consensus problem requires agreement among a number of processes (or agents) on a single data value. Some of the processes (agents) may fail or be unreliable in other ways, so consensus protocols mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptocurrencies
A cryptocurrency (colloquially crypto) is a digital currency designed to work through a computer network that is not reliant on any central authority, such as a government or bank, to uphold or maintain it. Individual coin ownership records are stored in a digital ledger or blockchain, which is a computerized database that uses a consensus mechanism to secure E-commerce, transaction records, control the creation of additional coins, and verify the transfer of coin ownership. The two most common consensus mechanisms are proof of work and proof of stake. Despite the name, which has come to describe many of the fungibility, fungible blockchain tokens that have been created, cryptocurrencies are not considered to be Currency, currencies in the traditional sense, and varying legal treatments have been applied to them in various jurisdictions, including classification as Commodity, commodities, Security (finance), securities, and currencies. Cryptocurrencies are generally viewed as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proof Of Personhood
Proof of personhood (PoP) is a means of resisting malicious attacks on peer to peer networks, particularly, attacks that utilize multiple fake identities, otherwise known as a Sybil attack. Decentralized online platforms are particularly vulnerable to such attacks by their very nature, as notionally democratic and responsive to large voting blocks. In PoP, each unique human participant obtains one equal unit of voting power, and any associated rewards. The term is used in for cryptocurrency and blockchains as a parallel to proof of work, proof of stake, and other consensus mechanisms which attempt to distribute voting power and rewards to participants proportionately to an investment of resources. Background The problem of Sybil attacks using many virtual identities has been recognized for decades as a fundamental challenge for distributed systems that expect each human user to have only one account or identity. CAPTCHAs attempt to rate-limit automated Sybil attacks by using ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proof Of Authority
Proof of authority (PoA) is an algorithm used with blockchains that delivers comparatively fast transactions through a consensus mechanism based on identity as a stake. The most notable platforms using PoA are VeChain, Bitgert, Palm Network and Xodex. Proof-of-authority In PoA-based networks, transactions and blocks are validated by approved accounts, known as validators. Validators run software allowing them to put transactions in blocks. The process is automated and does not require validators to be constantly monitoring their computers. It, however, does require maintaining the computer (the authority node) uncompromised. The term was coined by Gavin Wood, co-founder of Ethereum Ethereum is a decentralized blockchain with smart contract functionality. Ether (abbreviation: ETH) is the native cryptocurrency of the platform. Among cryptocurrencies, ether is second only to bitcoin in market capitalization. It is open-s ... and Parity Technologies. With PoA, individuals ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proof Of Stake
Proof-of-stake (PoS) protocols are a class of consensus mechanisms for blockchains that work by selecting validators in proportion to their quantity of holdings in the associated cryptocurrency. This is done to avoid the computational cost of proof-of-work (POW) schemes. The first functioning use of PoS for cryptocurrency was Peercoin in 2012, although its scheme, on the surface, still resembled a POW. Description For a blockchain transaction to be recognized, it must be appended to the blockchain. In the proof of stake blockchain, the appending entities are named ''minters'' or (in the proof of work blockchains this task is carried out by the miners); in most protocols, the validators receive a reward for doing so. For the blockchain to remain secure, it must have a mechanism to prevent a malicious user or group from taking over a majority of validation. PoS accomplishes this by requiring that validators have some quantity of blockchain tokens, requiring potential attack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proof Of Work
Proof of work (also written as proof-of-work, an abbreviated PoW) is a form of cryptographic proof in which one party (the ''prover'') proves to others (the ''verifiers'') that a certain amount of a specific computational effort has been expended. Verifiers can subsequently confirm this expenditure with minimal effort on their part. The concept was first implemented in Hashcash by Moni Naor and Cynthia Dwork in 1993 as a way to deter denial-of-service attacks and other service abuses such as spam on a network by requiring some work from a service requester, usually meaning processing time by a computer. The term "proof of work" was first coined and formalized in a 1999 paper by Markus Jakobsson and Ari Juels. The concept was adapted to digital tokens by Hal Finney in 2004 through the idea of "reusable proof of work" using the 160-bit secure hash algorithm 1 (SHA-1). Proof of work was later popularized by Bitcoin as a foundation for consensus in a permissionless decentralized n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard Disk Drive
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating hard disk drive platter, platters coated with magnetic material. The platters are paired with disk read-and-write head, magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual Block (data storage), blocks of data can be stored and retrieved in any order. HDDs are a type of non-volatile storage, retaining stored data when powered off. Modern HDDs are typically in the form of a small disk enclosure, rectangular box. Hard disk drives were introduced by IBM in 1956, and were the dominant secondary storage device for History of general-purpose CPUs, general-purpose computers beginning in the early 1960s. HDDs maintained this position into the modern er ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid-state Drives
A solid-state drive (SSD) is a type of solid-state storage device that uses integrated circuits to store data persistently. It is sometimes called semiconductor storage device, solid-state device, or solid-state disk. SSDs rely on non-volatile memory, typically NAND flash, to store data in memory cells. The performance and endurance of SSDs vary depending on the number of bits stored per cell, ranging from high-performing single-level cells (SLC) to more affordable but slower quad-level cells (QLC). In addition to flash-based SSDs, other technologies such as 3D XPoint offer faster speeds and higher endurance through different data storage mechanisms. Unlike traditional hard disk drives (HDDs), SSDs have no moving parts, allowing them to deliver faster data access speeds, reduced latency, increased resistance to physical shock, lower power consumption, and silent operation. Often interfaced to a system in the same way as HDDs, SSDs are used in a variety of devices, incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shabal
Shabal is a cryptographic hash function submitted by the France-funded research project Saphir to NIST's international competition on hash functions. Saphir partners The research partners of Saphir (with the exception of LIENS) initiated the conception of Shabal and were later joined by partners of the research project Saphir2 who actively contributed to the final design of Shabal. Saphir (Security and Analysis of Hash Primitives) is an ANR funded project on hash functions. Saphir has started in March 2006 for a duration of three years and brought five partners together: Cryptolog International, DCSSI, France Telecom (leader), Gemalto and LIENS. Partners of Saphir2 come from both industry and academia; in addition to partners of Saphir, 4 new partners: EADS SN, INRIA, Sagem Sécurité and UVSQ joined and contributed to the project. History Shabal was an entry in the NIST hash function competition, where it passed to the second round, but failed to enter the final round. Shabal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Client Puzzle Protocol
Client Puzzle Protocol (CPP) is a computer algorithm for use in Internet communication, whose goal is to make abuse of server resources infeasible. It is an implementation of a proof-of-work system (PoW). The idea of the CPP is to require all clients connecting to a server to correctly solve a mathematical puzzle before establishing a connection, if the server is under attack. After solving the puzzle, the client would return the solution to the server, which the server would quickly verify, or reject and drop the connection. The puzzle is made simple and easily solvable but requires at least a minimal amount of computation on the client side. Legitimate users would experience just a negligible computational cost, but abuse would be deterred: those clients that try to simultaneously establish a large number of connections would be unable to do so because of the computational cost (time delay). This method holds promise in fighting some types of spam as well as other attacks lik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chia (cryptocurrency)
Chia Network is a proof of space and proof of time-based blockchain. It issues the digital currency Chia (XCH). It was founded in 2017 by Bram Cohen, the creator of BitTorrent, and Ryan Singer. Its headquarters are in South San Francisco, California. History Chia Network was co-founded by Bram Cohen, the creator of BitTorrent, and Ryan Singer in 2017. Cohen said he was inspired by Bitcoin and the rise of cryptocurrency, and that he believed digital currencies would be safer, faster, and create more financial autonomy. He also had reservations about the various issues surrounding cryptocurrencies, such as the energy consumed in bitcoin mining. He created the Chia Network in an effort to design and launch the Chia blockchain, which used unused hard drive space, which would consume less energy than the proof of work protocol commonly used by blockchain networks. Chia blockchain runs on the company's programming language Chialisp. In 2018, Cohen raised $3.4 million in seed f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
