|
Blockchain
The blockchain is a distributed ledger with growing lists of Record (computer science), records (''blocks'') that are securely linked together via Cryptographic hash function, cryptographic hashes. Each block contains a cryptographic hash of the previous block, a Trusted timestamping, timestamp, and transaction data (generally represented as a Merkle tree, where Node (computer science), data nodes are represented by leaves). Since each block contains information about the previous block, they effectively form a ''chain'' (compare linked list data structure), with each additional block linking to the ones before it. Consequently, blockchain transactions are resistant to alteration because, once recorded, the data in any given block cannot be changed retroactively without altering all subsequent blocks and obtaining network consensus to accept these changes. Blockchains are typically managed by a peer-to-peer, peer-to-peer (P2P) computer network for use as a public distributed led ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptocurrency
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 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 fungible blockchain tokens that have been created, cryptocurrencies are not considered to be currencies in the traditional sense, and varying legal treatments have been applied to them in various jurisdictions, including classification as commodities, securities, and currencies. Cryptocurrencies are generally viewed as a distinct asset class in practice. The first cryptocu ... [...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] |
Bitcoin
Bitcoin (abbreviation: BTC; Currency symbol, sign: ₿) is the first Decentralized application, decentralized cryptocurrency. Based on a free-market ideology, bitcoin was invented in 2008 when an unknown entity published a white paper under the pseudonym of Satoshi Nakamoto. Use of bitcoin as a currency began in 2009, with the release of its open-source software, open-source implementation. In 2021, Bitcoin in El Salvador, El Salvador adopted it as legal tender. It is mostly seen as an investment and has been described by some scholars as an economic bubble. As bitcoin is pseudonymous, Cryptocurrency and crime, its use by criminals has attracted the attention of regulators, leading to Legality of cryptocurrency by country or territory, its ban by several countries . Bitcoin works through the collaboration of computers, each of which acts as a Node (networking), node in the peer-to-peer bitcoin network. Each node maintains an independent copy of a public distributed ledger of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fork (blockchain)
In blockchain, a fork is defined variously as: * "What happens when a blockchain diverges into two potential paths forward", * "A change in protocol", or * A situation that "occurs when two or more blocks have the same block height". Forks are related to the fact that different parties need to use common rules to maintain the history of the blockchain. When parties are not in agreement, alternative chains may emerge. While most forks are short-lived some are permanent. Short-lived forks are due to the difficulty of reaching fast consensus in a distributed system. Whereas permanent forks (in the sense of protocol changes) have been used to add new features to a blockchain, they can also be used to reverse the effects of hacking such as the case with Ethereum and Ethereum Classic, or avert catastrophic bugs on a blockchain as was the case with the bitcoin fork on 6 August 2010. The concept of blockchain technology was first introduced in 2008 by an unknown person or group of pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed Ledger
A distributed ledger (also called a shared ledger or distributed ledger technology or DLT) is a system whereby replicated, shared, and synchronized digital data is geographically spread (distributed) across many sites, countries, or institutions. Its fundamental rationale is Argumentum ad populum whereby its veracity relies on a popular or majority of nodes to force the system to agree. In contrast to a centralized database, a distributed ledger does not require a central administrator, and consequently does not have a Single point of failure, single (central) point-of-failure. In general, a distributed ledger requires a peer-to-peer, peer-to-peer (P2P) computer network and Consensus (computer science), consensus algorithms so that the ledger is reliably replicated across distributed computer nodes (servers, clients, etc.). The most common form of distributed ledger technology is the blockchain (commonly associated with the bitcoin cryptocurrency), which can either be on a public or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Byzantine Fault Tolerance
A Byzantine fault is a condition of a system, particularly a distributed computing system, where a fault occurs such that different symptoms are presented to different observers, including imperfect information on whether a system component has failed. The term takes its name from an allegory, the "Byzantine generals problem", developed to describe a situation in which, to avoid catastrophic failure of a system, the system's actors must agree on a strategy, but some of these actors are unreliable in such a way as to cause other (good) actors to disagree on the strategy and they may be unaware of the disagreement. A Byzantine fault is also known as a Byzantine generals problem, a Byzantine agreement problem, or a Byzantine failure. Byzantine fault tolerance (BFT) is the resilience of a fault-tolerant computer system or similar system to such conditions. Definition A Byzantine fault is any fault presenting different symptoms to different observers. A Byzantine failure is the los ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stuart Haber
Stuart Haber is an American cryptographer and computer scientist, known for his contributions in cryptography and privacy-preserving technologies and widely recognized as the co-inventor of the blockchain. His 1991 paper "How to Time-Stamp a Digital Document”, co-authored with W. Scott Stornetta, won the 1992 Discover Award for Computer Software and is considered to be one of the most important papers in the development of cryptocurrencies. Education Haber studied at Harvard University, graduating magna cum laude in 1978 with a B.A. in mathematics. Haber earned his PhD at Columbia University in 1987 under the advisement of Zvi Galil with a thesis titled ''Provably Secure Multi-party Cryptographic Computation: Techniques and Applications''. Career In 1987, Haber joined Bell Communications Research (Bellcore) as a research scientist. In 1989, Haber met W. Scott Stornetta, his future scientific partner and collaborator, when Stornetta joined Bellcore. In 1994, Haber and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trusted Timestamping
Trusted timestamping is the process of computer security, securely keeping track of the creation and modification time of a document. Security here means that no one—not even the owner of the document—should be able to change it once it has been recorded provided that the timestamper's integrity is never compromised. The administrative aspect involves setting up a publicly available, trusted timestamp management infrastructure to collect, process and renew timestamps. History The idea of timestamping information is centuries old. For example, when Robert Hooke discovered Hooke's law in 1660, he did not want to publish it yet, but wanted to be able to claim priority. So he published the anagram ''ceiiinosssttuv'' and later published the translation ''ut tensio sic vis'' (Latin for "as is the extension, so is the force"). Similarly, Galileo Galilei, Galileo first published his discovery of the phases of Venus in the anagram form. Sir Isaac Newton, in responding to questions f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satoshi Nakamoto
Satoshi Nakamoto ( – 26 April 2011) is the name used by the presumed pseudonymous person or persons who developed bitcoin, authored the bitcoin white paper, and created and deployed bitcoin's original reference implementation. As part of the implementation, Nakamoto also devised the first blockchain database. Nakamoto was active in the development of bitcoin until December 2010. There has been widespread speculation about Nakamoto's true identity, with various people posited as the person or persons behind the name. Though Nakamoto's name is Japanese, and inscribed as a man living in Japan, most of the speculation has involved software and cryptography experts in the United States or Europe. Development of bitcoin Nakamoto said that the work of writing bitcoin's code began in the second quarter of 2007. On 18 August 2008, he or a colleague registered the domain name bitcoin.org, and created a web site at that address. On 31 October, Nakamoto published a white paper on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Chaum
David Lee Chaum (born 1955) is an American computer scientist, List of cryptographers, cryptographer, and inventor. He is known as a pioneer in cryptography and privacy-preserving technologies, and widely recognized as the inventor of Digital currency, digital cash. His 1982 dissertation "Computer Systems Established, Maintained, and Trusted by Mutually Suspicious Groups" is the first known proposal for a blockchain protocol. Complete with the code to implement the protocol, Chaum's dissertation proposed all but one element of the blockchain later detailed in the Bitcoin White paper, whitepaper. He has been referred to as "the father of online anonymity", and "the godfather of cryptocurrency". He is also known for developing ecash, an electronic cash application that aims to preserve a user's anonymity, and inventing many cryptography, cryptographic protocols like the blind signature, mix networks and the Dining cryptographers protocol. In 1995 his company DigiCash created the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double-spending
Double-spending is the unauthorized production and spending of money, either digital or conventional. It represents a monetary design problem: a good money is verifiably scarce, and where a unit of value can be spent more than once, the monetary property of scarcity is challenged. As with counterfeit money, such double-spending leads to inflation by creating a new amount of copied currency that did not previously exist. Like all increasingly abundant resources, this devalues the currency relative to other monetary units or goods and diminishes user trust as well as the circulation and retention of the currency. Fundamental cryptographic techniques to prevent double-spending, while preserving anonymity in a transaction, are the introduction of an authority (and hence centralization) for blind signatures and, particularly in offline systems, secret splitting. Centralized digital currencies Prevention of double-spending is usually implemented using an online central trusted thi ... [...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] |
