Double Spending
   HOME
*





Double Spending
Double-spending is a fundamental flaw in a Digital currency, digital cash protocol in which the same single digital token can be spent more than once. Due to the nature of information space, in comparison to physical space (as in: valuable physical resources), a digital token (like a file) is inherently almost infinitely duplicable or falsifiable, leading to ownership of said token itself being undefinable unless declared so by a chosen authority. 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 (currency), 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 ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Digital Currency
Digital currency (digital money, electronic money or electronic currency) is any currency, money, or money-like asset that is primarily managed, stored or exchanged on digital computer systems, especially over the internet. Types of digital currencies include cryptocurrency, virtual currency and central bank digital currency. Digital currency may be recorded on a distributed database on the internet, a centralized electronic computer database owned by a company or bank, within digital files or even on a stored-value card. Digital currencies exhibit properties similar to traditional currencies, but generally do not have a classical physical form of fiat currency historically that you can directly hold in your hand, like currencies with printed banknotes or minted coins - however they do have a physical form in an unclassical sense coming from the computer to computer and computer to human interactions and the information and processing power of the servers that store and keep ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Bitcoin
Bitcoin ( abbreviation: BTC; sign: ₿) is a decentralized digital currency that can be transferred on the peer-to-peer bitcoin network. Bitcoin transactions are verified by network nodes through cryptography and recorded in a public distributed ledger called a blockchain. The cryptocurrency was invented in 2008 by an unknown person or group of people using the name Satoshi Nakamoto. The currency began use in 2009, when its implementation was released as open-source software. The word "''bitcoin''" was defined in a white paper published on October 31, 2008. It is a compound of the words ''bit'' and ''coin''. The legality of bitcoin varies by region. Nine countries have fully banned bitcoin use, while a further fifteen have implicitly banned it. A few governments have used bitcoin in some capacity. El Salvador has adopted Bitcoin as legal tender, although use by merchants remains low. Ukraine has accepted cryptocurrency donations to fund the resistance to the 2022 Russ ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Internet Fraud
Internet fraud is a type of cybercrime fraud or deception which makes use of the Internet and could involve hiding of information or providing incorrect information for the purpose of tricking victims out of money, property, and inheritance. Internet fraud is not considered a single, distinctive crime but covers a range of illegal and illicit actions that are committed in cyberspace. It is, however, differentiated from theft since, in this case, the victim voluntarily and knowingly provides the information, money or property to the perpetrator. It is also distinguished by the way it involves temporally and spatially separated offenders. According to the FBI's 2017 Internet Crime Report, the Internet Crime Complaint Center (IC3) received about 300,000 complaints. Victims lost over $1.4 billion in online fraud in 2017. According to a study conducted by the Center for Strategic and International Studies (CSIS) and McAfee, cybercrime costs the global economy as much as $600 billion, w ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Payment Systems
A payment system is any system used to settle financial transactions through the transfer of monetary value. This includes the institutions, instruments, people, rules, procedures, standards, and technologies that make its exchange possible.Biago Bossone and Massimo Cirasino, "The Oversight of the Payment Systems: A Framework for the Development and Governance of Payment Systems in Emerging Economies"The World Bank, July 2001, p.7 A common type of payment system, called an operational network, links bank accounts and provides for monetary exchange using bank deposits. Some payment systems also include credit mechanisms, which are essentially a different aspect of payment. Payment systems are used in lieu of tendering cash in domestic and international transactions. This consists of a major service provided by banks and other financial institutions. Traditional payment systems include negotiable instruments such as drafts (e.g., cheques) and documentary credits such as letters of ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Financial Cryptography
Financial cryptography is the use of cryptography in applications in which financial loss could result from subversion of the message system. Financial cryptography is distinguished from traditional cryptography in that for most of recorded history, cryptography has been used almost entirely for military and diplomatic purposes. Financial cryptography includes the mechanisms and algorithms necessary for the protection of financial transfers, in addition to the creation of new forms of money. Proof of work and various auction protocols fall under the umbrella of Financial cryptography. Hashcash is being used to limit spam. Financial cryptography has been seen to have a very broad scope of application. Ian Grigg sees financial cryptography in seven layers, being the combination of seven distinct disciplines: cryptography, software engineering, rights, accounting, governance, value, and financial applications. Business failures can often be traced to the absence of one or more of thes ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  




Digital Currencies
Digital currency (digital money, electronic money or electronic currency) is any currency, money, or money-like asset that is primarily managed, stored or exchanged on digital computer systems, especially over the internet. Types of digital currencies include cryptocurrency, virtual currency and central bank digital currency. Digital currency may be recorded on a distributed database on the internet, a centralized electronic Database, computer database owned by a company or bank, within Computer file, digital files or even on a stored-value card. Digital currencies exhibit properties similar to traditional currencies, but generally do not have a classical physical form of fiat currency historically that you can directly hold in your hand, like currencies with printed banknotes or minted coins - however they do have a physical form in an unclassical sense coming from the computer to computer and computer to human interactions and the information and processing power of the serve ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Ghash
In cryptography, Galois/Counter Mode (GCM) is a mode of operation for symmetric-key cryptographic block ciphers which is widely adopted for its performance. GCM throughput rates for state-of-the-art, high-speed communication channels can be achieved with inexpensive hardware resources. The operation is an authenticated encryption algorithm designed to provide both data authenticity (integrity) and confidentiality. GCM is defined for block ciphers with a block size of 128 bits. Galois Message Authentication Code (GMAC) is an authentication-only variant of the GCM which can form an incremental message authentication code. Both GCM and GMAC can accept initialization vectors of arbitrary length. Different block cipher modes of operation can have significantly different performance and efficiency characteristics, even when used with the same block cipher. GCM can take full advantage of parallel processing and implementing GCM can make efficient use of an instruction pipeline or a hard ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Bitcoin Gold
Bitcoin Gold (BTG) is a cryptocurrency. It is a hard fork of Bitcoin, the open source cryptocurrency. It is an open source, decentralized digital currency without a central bank or intermediary that can be sent from user to user on the peer-to-peer Bitcoin Gold network. The stated purpose of the hard fork is to change the proof of work algorithm so that ASICs (Application-Specific Integrated Circuits) which are used to mine Bitcoin cannot be used to mine the Bitcoin Gold blockchain in the hopes that enabling mining on commonly available graphics cards will democratize and decentralize the mining and distribution of the cryptocurrency. The project began as a community-driven effort with six co-founders, half of whom continue to serve on the project's Board (including Lead Developer, Hang Yin.) History Bitcoin Gold hard forked from the Bitcoin blockchain on October 24, 2017, at block height 491407. In July 2018, Bitcoin Gold implemented a new mining algorithm. The actual alg ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


Mining Pool
In the context of cryptocurrency mining, a mining pool is the pooling of resources by miners, who share their processing power over a network, to split the reward equally, according to the amount of work they contributed to the probability of finding a block. A "share" is awarded to members of the mining pool who present a valid partial proof-of-work. Mining in pools began when the difficulty for mining increased to the point where it could take centuries for slower miners to generate a block. The solution to this problem was for miners to pool their resources so they could generate blocks more quickly and therefore receive a portion of the block reward on a consistent basis, rather than randomly once every few years. History * November 2010: Slush launched in 2010 and is the first mining pool. * 2011–2013: The era of deepbit, which at its peak held up to 45% of the network hashrate. * 2013–2014: Since the introduction of ASIC, and when deepbit failed to support the newer ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Bitcoin Mining
The bitcoin network is a peer-to-peer payment network that operates on a cryptographic protocol. Users send and receive bitcoins, the units of currency, by broadcasting digitally-signed messages to the network using bitcoin cryptocurrency wallet software. Transactions are recorded into a distributed, replicated, public database known as the blockchain, with consensus achieved by a proof-of-work system called ''mining''. Satoshi Nakamoto, the anonymous designer of the protocol, stated that design and coding of bitcoin began in 2007. The project was released in 2009 as open source software. The network requires minimal structure to share transactions. An ad hoc decentralized network of volunteers is sufficient. Messages are broadcast on a best-effort basis, and nodes can leave and rejoin the network at will. Upon reconnection, a node downloads and verifies new blocks from other nodes to complete its local copy of the blockchain. Transactions A bitcoin is defined by a seq ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Hash Collision
In computer science, a hash collision or hash clash is when two pieces of data in a hash table share the same hash value. The hash value in this case is derived from a hash function which takes a data input and returns a fixed length of bits. Although hash algorithms have been created with the intent of being collision resistant, they can still sometimes map different data to the same hash (by virtue of the pigeonhole principle). Malicious users can take advantage of this to mimic, access, or alter data. Due to the possible negative applications of hash collisions in data management and computer security (in particular, cryptographic hash functions), collision avoidance has become an important topic in computer security. Background Hash collisions can be unavoidable depending on the number of objects in a set and whether or not the bit string they are mapped to is long enough in length. When there is a set of ''n'' objects, if ''n'' is greater than , ''R'', , which in this ca ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Blockchain
A blockchain is a type of distributed ledger technology (DLT) that consists of growing lists of records, called ''blocks'', that are securely linked together using cryptography. Each block contains a cryptographic hash of the previous block, a timestamp, and transaction data (generally represented as a Merkle tree, where data nodes are represented by leaves). The timestamp proves that the transaction data existed when the block was created. 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 irreversible in that, once they are recorded, the data in any given block cannot be altered retroactively without altering all subsequent blocks. Blockchains are typically managed by a peer-to-peer, peer-to-peer (P2P) computer network for use as a public distributed ledger, where nodes collectively adhere to ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]