A cypherpunk is any individual advocating widespread use of strong cryptography and privacy-enhancing technologies as a route to social and political change. Originally communicating through the Cypherpunks electronic mailing list, informal groups aimed to achieve privacy and security through proactive use of cryptography. Cypherpunks have been engaged in an active movement since at least the late 1980s.
Leonard Harris Sassaman was an American technologist, information privacy advocate, and the maintainer of the Mixmaster anonymous remailer code and operator of the randseed remailer. Much of his career gravitated towards cryptography and protocol development.
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.
David Lee Chaum is an American computer scientist, cryptographer, and inventor. He is known as a pioneer in cryptography and privacy-preserving technologies, and widely recognized as the inventor of 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 whitepaper. He has been referred to as "the father of online anonymity", and "the godfather of cryptocurrency".
Hashcash is a proof-of-work system used to limit email spam and denial-of-service attacks. Hashcash was proposed in 1997 by Adam Back and described more formally in Back's 2002 paper "Hashcash - A Denial of Service Counter-Measure". In Hashcash the client has to concatenate a random number with a string several times and hash this new string. It then has to do so over and over until a hash beginning with a certain amount of zeros is found.
Proof of work (PoW) is a form of cryptographic proof in which one party proves to others 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 invented 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).
Dave Kleiman was an American computer forensics expert, an author or co-author of multiple books and a frequent speaker at security related events.
Harold Thomas Finney II was an American software developer. In his early career, he was credited as lead developer on several console games. He later worked for PGP Corporation. He was an early Bitcoin contributor, and received the first Bitcoin transaction from the currency's creator Satoshi Nakamoto.
Bitcoin is the first decentralized cryptocurrency. Nodes in the peer-to-peer bitcoin network verify transactions through cryptography and record them in a public distributed ledger, called a blockchain, without central oversight. Consensus between nodes is achieved using a computationally intensive process based on proof of work, called mining, that requires increasing quantities of electricity and guarantees the security of the bitcoin blockchain.
Satoshi Nakamoto 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.
A cryptocurrency, crypto-currency, or crypto is a digital currency designed to work as a medium of exchange through a computer network that is not reliant on any central authority, such as a government or bank, to uphold or maintain it.
The Bitcoin protocol is the set of rules that govern the functioning of Bitcoin. Its key components and principles are: a peer-to-peer decentralized network with no central oversight; the blockchain technology, a public ledger that records all Bitcoin transactions; mining and proof of work, the process to create new bitcoins and verify transactions; and cryptographic security.
Bitcoin is a cryptocurrency, a digital asset that uses cryptography to control its creation and management rather than relying on central authorities. Originally designed as a medium of exchange, Bitcoin is now primarily regarded as a store of value. The history of bitcoin started with its invention and implementation by Satoshi Nakamoto, who integrated many existing ideas from the cryptography community. Over the course of bitcoin's history, it has undergone rapid growth to become a significant store of value both on- and offline. From the mid-2010s, some businesses began accepting bitcoin in addition to traditional currencies.
Nicholas Szabo is a computer scientist, legal scholar, and cryptographer known for his research in digital contracts and digital currency. He graduated from the University of Washington in 1989 with a degree in computer science and received a Juris Doctor degree from George Washington University Law School. He holds an honorary professorship at the Universidad Francisco Marroquín.
Blockstream is a blockchain technology company led by co-founder Adam Back, headquartered in Victoria, Canada, with offices and staff worldwide. The company develops a range of products and services for the storage and transfer of Bitcoin and other digital assets.
Wei Dai is a computer engineer known for contributions to cryptography and cryptocurrencies. He developed the Crypto++ cryptographic library, created the b-money cryptocurrency system, and co-proposed the VMAC message authentication algorithm.
Craig Steven Wright is an Australian computer scientist and businessman. He has publicly claimed to be the main part of the team that created bitcoin, and the identity behind the pseudonym Satoshi Nakamoto. These claims are generally regarded as false by the media and the cryptocurrency community. In March 2024, Mr Justice James Mellor in the British High Court ruled that Wright is not Nakamoto. As of 2019, Wright lives in the United Kingdom.
In cryptocurrencies, an unspent transaction output (UTXO) is a distinctive element in a subset of digital currency models. A UTXO represents a certain amount of cryptocurrency that has been authorized by a sender and is available to be spent by a recipient. The utilization of UTXOs in transaction processes is a key feature of many cryptocurrencies, but it primarily characterizes those implementing the UTXO model.
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.
