Cryptocurrency

cryptocurrenciescryptocrypto-currency
Cryptocurrencies use decentralized control as opposed to centralized digital currency and central banking systems. The decentralized control of each cryptocurrency works through distributed ledger technology, typically a blockchain, that serves as a public financial transaction database. Bitcoin, first released as open-source software in 2009, is generally considered the first decentralized cryptocurrency. Since the release of bitcoin, over 6,000 altcoins (alternative variants of bitcoin, or other cryptocurrencies) have been created. In 1983, the American cryptographer David Chaum conceived an anonymous cryptographic electronic money called ecash.

Peer-to-peer

P2Ppeer to peerpeer-to-peer network
Bitcoin and alternatives such as Ether, Nxt and Peercoin are peer-to-peer-based digital cryptocurrencies. Dalesa, a peer-to-peer web cache for LANs (based on IP multicasting). FAROO, a peer-to-peer web search engine. Filecoin is an open source, public, cryptocurrency and digital payment system intended to be a blockchain-based cooperative digital storage and data retrieval method. I2P, an overlay network used to browse the Internet anonymously. Infinit is an unlimited and encrypted peer to peer file sharing application for digital artists written in C++.

Ethereum

EtherERC-20Ethereum Virtual Machine
The basic idea of putting executable smart contracts in the blockchain needed to be specified before the software could be implemented; this work was done by Gavin Wood, then chief technology officer, in the Ethereum Yellow Paper that specified the Ethereum Virtual Machine. Subsequently, a Swiss non-profit foundation, the Ethereum Foundation (Stiftung Ethereum), was created as well. Development was funded by an online public crowdsale during July–August 2014, with the participants buying the Ethereum value token (ether) with another digital currency, bitcoin.

Proof of work

proof-of-workproof-of-work systemreusable proof of work
In 2009, the Bitcoin network went online. Bitcoin is a proof-of-work cryptocurrency that, like Finney's RPoW, is also based on the Hashcash PoW. But in Bitcoin double-spend protection is provided by a decentralized P2P protocol for tracking transfers of coins, rather than the hardware trusted computing function used by RPoW. Bitcoin has better trustworthiness because it is protected by computation. Bitcoins are "mined" using the Hashcash proof-of-work function by individual miners and verified by the decentralized nodes in the P2P bitcoin network. The difficulty is periodically adjusted to keep the block time around a target time.

Cryptography

cryptographiccryptographercryptology
Applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synonymous with encryption, the conversion of information from a readable state to apparent nonsense. The originator of an encrypted message shares the decoding technique only with intended recipients to preclude access from adversaries. The cryptography literature often uses the names Alice ("A") for the sender, Bob ("B") for the intended recipient, and Eve ("eavesdropper") for the adversary.

Coinbase

Brian ArmstrongBrian Armstrong (CEO)GDAX
Coinbase is a digital currency exchange headquartered in San Francisco, California. They broker exchanges of Bitcoin, Bitcoin Cash, Ethereum, Ethereum Classic, and Litecoin with fiat currencies in approximately 32 countries, and bitcoin transactions and storage in 190 countries worldwide. Coinbase was founded in June 2012 by Brian Armstrong and Fred Ehrsam. Blockchain.info co-founder Ben Reeves was part of the original founding team but later parted ways with Armstrong due to a difference in how the Coinbase wallet should operate. The remaining founding team enrolled in the Summer 2012 Y Combinator startup incubator program.

Economics of bitcoin

Bitcoin is a digital asset designed by its inventor, Satoshi Nakamoto, to work as a currency. Bitcoin is a digital asset designed by its inventor, Satoshi Nakamoto, to work as a currency. It is commonly referred to with terms like: digital currency, digital cash, virtual currency, electronic currency, digital gold, or cryptocurrency. The question whether bitcoin is a currency or not is disputed. Bitcoins have three useful qualities in a currency, according to The Economist in January 2015: they are "hard to earn, limited in supply and easy to verify".

List of pioneers in computer science

computer pioneerfather of the computerList of prominent pioneers in computer science
This article presents a list of individuals who made transformative breakthroughs in the creation, development and imagining of what computers and electronics could do.

Double-spending

51% attackdouble spending51% attacks
Decentralized currencies that rely on blockchain are vulnerable to the 51% attack, in which a malicious actor can rewrite the ledger if they control enough of the computational work being done.

History of money

monetary historyabandonmentan international currency of the early ages
By 1990, in the United States all money transferred between its central bank and commercial banks was in electronic form. By the 2000s most money existed as digital currency in banks databases. In 2012, by number of transaction, 20 to 58 percent of transactions were electronic (dependent on country). In 2008, Bitcoin was proposed by an unknown author/s under the pseudonym of Satoshi Nakamoto, it was implemented the same year. Its use of cryptography allowed the currency to have a trustless, fungible and tamper resistant distributed ledger called a blockchain. It became the first widely used decentralized, peer-to-peer, cryptocurrency.

Banknote

paper moneybanknotespaper currency
Meanwhile, it rates digital currency a pretty complicated decision and is analyzing the pros and cons and working to determine under which conditions it may make sense to, one day, issue a digital currency. As a threat, a central bank digital currency could increase the risk of a run on the banking system. Also in 2012, Sveriges Riksbank, the central bank of Sweden, was reported to analyze technological advances with regard to electronic money and payment methods for digital currency as an alternative to cash.

Bitcoin Core

Bitcoin Improvement ProposalCheckLockTimeVerifyCheckSequenceVerify
Bitcoin Core uses OpenTimestamps to timestamp merge commits. Bitcoin 0.1 was released on 9 January 2009 by Satoshi Nakamoto with only Windows supported. This was followed by some minor bug fixing versions. On 16 December 2009 Bitcoin 0.2 was released. It included a Linux version for the first time and made use of multi-core processors for mining. In version 0.3.2 Nakamoto included checkpoints as a safeguard. After the release of version 0.3.9 Satoshi Nakamoto left the project and shortly after stopped communicating on online forums. Between 2011 and 2013 new versions of the software were released at Bitcoin.org.

List of cryptocurrencies

List of scrypt crypto currenciesSHA-256 crypto currencies
By market capitalization, Bitcoin is currently (December 15, 2018) the largest blockchain network, followed by Ripple, Ethereum and Tether. As of 15 December 2018, total cryptocurrencies market capitalization is $100bn and larger than GDP of 127 countries. Below are some notable cryptocurrencies: *List of digital currencies

Litecoin

LTC
Litecoin is different in some ways from Bitcoin. Due to Litecoin's use of the scrypt algorithm, FPGA and ASIC devices made for mining Litecoin are more complicated to create and more expensive to produce than they are for Bitcoin, which uses SHA-256. * List of scrypt crypto currencies * The Litecoin Network aims to process a block every 2.5 minutes, rather than Bitcoin's 10 minutes. This allows Litecoin to confirm transactions much faster than Bitcoin. Litecoin uses scrypt in its proof-of-work algorithm, a sequential memory-hard function requiring asymptotically more memory than an algorithm which is not memory-hard.

Money

monetaryspeciecash
By 1990, in the United States all money transferred between its central bank and commercial banks was in electronic form. By the 2000s most money existed as digital currency in bank databases. In 2012, by number of transaction, 20 to 58 percent of transactions were electronic (dependant on country). Non-national digital currencies were developed in the early 2000s. In particular, Flooz and Beenz had gained momentum before the Dot-com bubble. Not much innovation occurred until the conception of Bitcoin in 2009, which introduced the concept of a cryptocurrency – a decentralised trustless currency.

Internet

onlinethe Internetweb
Compared to printed media, books, encyclopedias and traditional libraries, the World Wide Web has enabled the decentralization of information on a large scale. The Web has enabled individuals and organizations to publish ideas and information to a potentially large audience online at greatly reduced expense and time delay. Publishing a web page, a blog, or building a website involves little initial cost and many cost-free services are available. However, publishing and maintaining large, professional web sites with attractive, diverse and up-to-date information is still a difficult and expensive proposition.

E-gold

Douglas Jackson (businessman)eGoldDouglas Jackson
While PayPal has done a better job of addressing abuse than e-gold did, they now contend with the same kind of Internet fraud that took down e-gold. Financial cryptographers have observed that Bitcoin has repeated the same fundamental errors that e-gold made, and that despite its decentralized nature the cyber crime-wave might bring Bitcoin to a similar ending. According to GoldMoney's website, BitGold announced the acquisition of GoldMoney on May 22, 2015. * Bitcoin. Digital currency. Digital currency exchanger. Gold as an investment. Liberty Reserve. PayPal. Private currency. WebMoney.

Mining pool

miners pool resourcespoolpooled
Digital currency exchanger. Electronic money. Pooled mining in Bitcoin Wiki. An estimation of hashrate distribution amongst the largest mining pools.

Payment system

payment systemspayment networkpayments system
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 it exchange possible. A common type of payment system is called an operational network that 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.

Libra (cryptocurrency)

LibraCalibraCalibra (company)
Beenz – an earlier attempt at an internet-wide digital currency. Facebook Credits. Flooz – an earlier attempt at an internet-wide digital currency. List of online payment service providers.

Financial transaction

transactiontransactionsfinancial transactions
As fixed currencies were gradually replaced by floating currencies during the 20th century, and as the recent development of computer networks made electronic money possible, financial transactions have rapidly increased in speed and complexity. In 1997, 1.3 billion US dollars were exchanged per day on the foreign exchange market, roughly 475 billion US dollars annually. The world financial transactions have jumped from 1.1 quadrillion US dollars in 2002 to 2.2 quadrillion US dollars in 2008. 95% of this is speculation. A financial transaction always involves one or more financial asset.

Privacy and blockchain

Private keys are used to access funds and personal wallets on the blockchain; they add a layer of identity authentication. When individuals wish to send money to other users, they must provide a digital signature that is produced when provided with the private key. This process protects against theft of funds. Blockchain technology arose from the creation of Bitcoin. In 2008, Satoshi Nakamoto released a paper describing the technology behind blockchains. In his paper, he explained a decentralized network that was characterized by peer-to-peer transactions involving cryptocurrencies or electronic money.

Namecoin

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Namecoin (Symbol: ℕ or NMC) is a cryptocurrency originally forked from bitcoin software. It is based on the code of bitcoin and uses the same proof-of-work algorithm. Like bitcoin, it is limited to 21 million coins. Namecoin can store data within its own blockchain transaction database. The original proposal for Namecoin called for Namecoin to insert data into bitcoin's blockchain directly. Anticipating scaling difficulties with this approach, a shared proof-of-work (POW) system was proposed to secure new cryptocurrencies with different use cases.

History of bitcoin

History of Virtual Cryptobanking with BitCoin
"Satoshi Nakamoto" is presumed to be a pseudonym for the person or people who designed the original bitcoin protocol in 2008 and launched the network in 2009. Nakamoto was responsible for creating the majority of the official bitcoin software and was active in making modifications and posting technical information on the bitcoin forum. There has been much speculation as to the identity of Satoshi Nakamoto with suspects including Dai, Szabo, and Finney – and accompanying denials. The possibility that Satoshi Nakamoto was a computer collective in the European financial sector has also been discussed.

List of highest-funded crowdfunding projects

List of highest funded crowdfunding projectshighest funded film campaign on Indiegogohighest-funded crowdfunding projects
This is an incomplete list of the highest-funded crowdfunding projects (including projects which failed to achieve funding).