Daniel Larimer

His interest in blockchains began in 2009, in the early days of Bitcoin. Larimer developed the blockchain technology Graphene, which powers BitShares and the Steem token cryptocurrency. In 2013, Larimer started BitShares. BitShares were originally named ProtoShares and intended to function as shares of virtual companies. BitShares has since been described as a cryptocurrency platform, a digital currency, or a digital exchange. It is organized as a decentralized autonomous organization (DAO). In 2016 Larimer left BitShares to found Steemit, a social network which uses blockchain technology to reward users. After founding Steemit, Larimer was CTO of the platform until March 2017.

Daniel Harple

Dan Harple
Harple described the new digital framework, written collaboratively by digital currency industry stakeholders, as "an inclusive platform to transform how we, as collective Internet users, can take back our personal data, and share it in a trusted and secure way — not only for Bitcoin and digital currency transactions, but for other data and media types as well". The Windhover principles were subsequently endorsed by 21 of the leading Bitcoin and digital currency companies. In March 2016, R. R. Donnelley & Sons teamed with Harple's Context Labs to pursue blockchain-enabled technology for its global publishing customers.

History of money

monetary historyabandonmentan international currency of the early ages
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 (dependant 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. Other comparable systems had been proposed since the 1980s.

Payment rail

Blockchain is considered a newer type of payment rail, as are centralized electronic payment systems such as PayPal and Venmo. If the transferred funds are available immediately, a payment rail is referred to as a real-time rail.


Segregated Witness
In May 2017 Digital Currency Group (not to be confused with the Digital Currency Initiative of the MIT Media Lab) announced it had offered a proposal, referred to as SegWit2x ("the New York Agreement"), activating Segregated Witness at an 80% threshold of the total bitcoin hash rate, signaling at bit 4; and activating a 2 MB block size limit within six months with support in excess of 80% of the total bitcoin hash rate. As of mid-2017 the SegWit2x proposal had support in excess of 90% of the hashrate, however the SegWit2x proposal has been controversial in that work on the project is limited to an invitation only group of developers.

David A. Marcus

David Marcus
According to the announcement, he was chosen based on his experience with digital payments at both PayPal and Facebook and his knowledge of cryptocurrency. He is also considered an early promoter of cryptocurrency. On May 8, 2018, Marcus revealed that he is stepping down from his current role to lead the experimental blockchain group to explore the possibilities for the use of blockchain for Facebook.


Bitstamp is a bitcoin exchange based in Luxembourg. It allows trading between USD currency and bitcoin cryptocurrency. It allows USD, EUR, bitcoin, litecoin, ethereum, ripple or bitcoin cash deposits and withdrawals. The company was founded as a European-focused alternative to then-dominant bitcoin exchange Mt. Gox. While the company trades in US dollars, it accepts fiat money deposits for free only via the European Union's Single Euro Payments Area, a mechanism for transferring money between European bank accounts. Deposits via credit cards or wires incur a fee. Bitstamp offers an API to allow clients to use custom software to access and control their accounts.


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. When gold and silver are used as money, the money supply can grow only if the supply of these metals is increased by mining.

Trusted timestamping

timestamptimestampedDecentralized timestamping
With the advent of cryptocurrencies like bitcoin, it has become possible to securely timestamp information in a decentralized and tamper-proof manner. Digital data can be hashed and the hash can be incorporated into a transaction stored in the blockchain, which serves as a secure proof of the exact time at which that data existed. The proof is due to a tremendous amount of computational effort performed after the hash was submitted to the blockchain. Tampering with the timestamp would require more computational resources than the rest of the network combined, and cannot be done unnoticed.

Kraken (company)

KrakenKraken cryptocurrency exchangeKraken exchange
In August Kraken listed Bitcoin Cash a hard-fork of Bitcoin with all clients that held bitcoin before the fork receiving an equal amount of Bitcoin Cash. In December it has been reported that Kraken was registering up to 50,000 new users a day. In April 2018, Kraken announced to shut its services in Japan, after operating since October 2014, by the end of June due to the rising costs of doing business there. Main article: Bankruptcy; stolen bitcoin In November 2014, Nobuaki Kobayashi, the court-appointed bankruptcy trustee overseeing the Mt.

Distributed ledger

distributed ledger technologyDistributed Ledger Technology (DLT)
One form of distributed ledger design is the blockchain system, which can be either public or private. The distributed ledger database is spread across several nodes (devices) on a peer-to-peer network, where each replicates and saves an identical copy of the ledger and updates itself independently. The primary advantage is the lack of central authority. When a ledger update happens, each node constructs the new transaction, and then the nodes vote by consensus algorithm on which copy is correct. Once a consensus has been determined, all the other nodes update themselves with the new, correct copy of the ledger. Security is accomplished through cryptographic keys and signatures.

Fork (blockchain)

hard forkforkfork referring to a blockchain
In cryptocurrencies, a fork is defined variously as Forks are related to the fact that different parties need to use common rules to maintain the history of the blockchain. Forks (in the sense of protocol changes) have been used in order to add new features to a blockchain, to reverse the effects of hacking or catastrophic bugs on a blockchain as was the case with the bitcoin fork on 6 August 2010 or the fork between Ethereum and Ethereum Classic. Notably, blockchain forks have been widely discussed in the context of the bitcoin scalability problem. Forks can be classified as accidental or intentional. Accidental fork happens when two or more miners find a block at nearly the same time.

Adam Back

Back, Adam
Today he is CEO of Blockstream, a company that seeks to further the development of bitcoin and blockchain technology. He has a computer science Ph.D. from University of Exeter. Data security. Information privacy.


paper moneybanknotespaper currency
Banknotes have increasingly been displaced by credit and debit cards and electronic money transfers. Some governments, such as Canada, are considering replacing paper notes and coins with digital currency. Sweden has begun implementing digital currency. Banknote collecting, or Notaphily, is a slowly growing area of numismatics. Although generally not as widespread as coin and stamp collecting, the hobby is slowly expanding. Prior to the 1990s, currency collecting was a relatively small adjunct to coin collecting, but currency auctions and greater public awareness of paper money have caused more interest in rare banknotes and consequently their increased value.


Facebook LiveFacebook, Inc.Facebook page
It received its first investment later that month from PayPal co-founder Peter Thiel. In 2005, the company dropped "the" from its name after purchasing the domain name facebook.com for US$200,000. The domain facebook.com belonged to AboutFace Corporation before the purchase. This website last appeared on April 8, 2005; from April 10, 2005, to August 4, 2005, this domain gave a 403 error. In May 2005, Accel Partners invested $12.7 million in Facebook, and Jim Breyer added $1 million of his own money. A high-school version of the site was launched in September 2005, which Zuckerberg called the next logical step. (At the time, high-school networks required an invitation to join.)


SHA-256sha256Secure Hash Algorithm 2
Several cryptocurrencies like Bitcoin use SHA-256 for verifying transactions and calculating proof of work or proof of stake. The rise of ASIC SHA-2 accelerator chips has led to the use of scrypt-based proof-of-work schemes. SHA-1 and SHA-2 are the Secure Hash Algorithms required by law for use in certain U.S. Government applications, including use within other cryptographic algorithms and protocols, for the protection of sensitive unclassified information. FIPS PUB 180-1 also encouraged adoption and use of SHA-1 by private and commercial organizations. SHA-1 is being retired for most government uses; the U.S.

Digital signature

digital signaturesdigitally signeddigitally sign
A scheme by Mihir Bellare and Gregory Neven may be used with Bitcoin. Signatures with efficient protocols - are signature schemes that facilitate efficient cryptographic protocols such as zero-knowledge proofs or secure computation. 21 CFR 11. X.509. Advanced electronic signature. Blind signature. Detached signature. Digital certificate. Digital signature in Estonia. Electronic lab notebook. Electronic signature. Electronic signatures and law. eSign (India). GNU Privacy Guard. Public key infrastructure. Server-based signatures. Probabilistic signature scheme. J. Katz and Y. Lindell, "Introduction to Modern Cryptography" (Chapman & Hall/CRC Press, 2007).

Bitcoin XT

Subsequently, Release H was published, which supported the November 2017 Bitcoin Cash protocol upgrade, followed by Release I, which supported the May 2018 Bitcoin Cash protocol upgrade. * Bitcoin XT on GitHub List of bitcoin forks. List of software forks. Bitcoin scalability problem.

Digital asset

digital assetsart assetassets
In 2015, Forbes and other sources characterized bitcoin as a digital asset. A digital asset management (DAM) system represents an intertwined structure incorporating both software and hardware and/or other services in order to manage, store, ingest, organise and retrieve digital assets. Digital asset management systems allow users to find and use content when they need it. Metadata is data about other data. Any structured information which's purpose is to define a specification of any form of data is referred to as metadata. "An item of metadata is a relationship that someone claims to exist between two entities".