Used to receive and send transactions on the network. An address is a string of alphanumeric characters, but can also be represented as a scannable QR code. They are derived from the public/private ECDSA key pair.
Distributed ledgers used by two or more parties to negotiate and reach and agreement.
An abbreviation of "Bitcoin alternative". Currently, the majority of altcoins are forks of Bitcoin with usually minor changes to the proof of work (POW) algorithm of the Bitcoin blockchain. The most prominent altcoin is Litecoin. Litecoin introduces changes to the original Bitcoin protocol such as decreased block generation time, increased maximum number of coins and different hashing algorithm.
Distributed ledgers that provide a durable record of agreements, commitments or statements, providing evidence (attestation) that these agreements, commitments or statements were made.
An acronym for "Application Specific Integrated Circuit". ASICs are silicon chips specifically designed to do a single task. In the case of bitcoin, they are designed to process SHA-256 hashing problems to mine new bitcoins.
A type of distributed ledger, comprised of unchangable, digitally recorded data in packages called blocks (rather like collating them on to a single sheet of paper). Each block is then ‘chained’ to the next block, using a cryptographic signature. This allows block chains to be used like a ledger, which can be shared and accessed by anyone with the appropriate permissions.
A method of encrypting text (to produce ciphertext) in which a cryptographic key and algorithm are applied to a block of data at once as a group rather than to one bit at a time.
Refers to the number of blocks connected together in the block chain. For example, Height 0, would be the very first block, which is also called the Genesis Block.
Rewards given to a miner which has successfully hashed a transaction block. Block rewards can be a mixture of coins and transaction fees, depending on the policy used by the cryptocurrency in question, and whether all of the coins have already been successfully mined. The current block reward for the Bitcoin network is 25 bitcoins for each block.
Refers to a ledger maintained by a central agency.
The process of connecting two blockchains with each other, thus allowing transactions between the chains to take place. This will allow blockchains like Bitcoin to communicate with other sidechains, allowing the exchange of assets between them
The blockchain transaction has been verified by the network. This happens through a process known as mining, in a proof-of-work system (e.g. Bitcoin). Once a transaction is confirmed, it cannot be reversed or double spent. The more confirmations a transaction has, the harder it becomes to perform a double spend attack.
A blockchain where the consensus process is controlled by a pre-selected set of nodes; for example, one might imagine a consortium of 15 financial institutions, each of which operates a node and of which ten must sign every block for the block to be valid. The right to read the blockchain may be public or restricted to the participants. There are also hybrid routes such as the root hashes of the blocks being public together with an API that allows members of the public to make a limited number of queries and get back cryptographic proofs of some parts of the blockchain state. These blockchains may be considered "partially decentralized".
The study of methods for obtaining the meaning of encrypted information, without access to the secret information that is normally required to do so.
A form of digital currency based on mathematics, where encryption techniques are used to regulate the generation of units of currency and verify the transfer of funds. Furthermore, cryptocurrencies operate independently of a central bank.
Refers to the process of encrypting and decrypting information.
A decentralized application that must be completely open-source, it must operate autonomously, and with no entity controlling the majority of its tokens.
(Decentralized Autonomous Organization) can be thought of as a corporation run without any human involvement under the control of an incorruptible set of business rules.
The process of turning cipher-text back into plaintext
The process of turning a clear-text message (plaintext) into a data stream (cipher-text), which looks like a meaningless and random sequence of bits.
A specfication for tokens on Ethereum.
An open software platform based on blockchain technology that enables developers to write smart contracts and build and deploy decentralized applications.
The Ethereum Virtual Machine.
The programming language in which accounts on the Ethereum blockchain can contain code. The EVM code associated with an account is executed every time a message is sent to that account, and has the ability to read/write storage and itself send messages.
A scarce, electronically transferrable, intangible, with a market value.
An online or networked identity adopted or claimed in cyberspace by an individual, organization, or electronic device.
A type of database that are spread across multiple sites, countries or institutions. Records are stored one after the other in a continuous ledger. Distributed ledger data can be either "permissioned" or "unpermissioned" to control who can view it.
In Proof-of-Work mining, is how hard it is to verify blocks in a blockchain network. In the Bitcoin network, the difficulty of mining adjusts verifying blocks every 2016 blocks. This is to keep block verification time at ten minutes.
Refers to a scenario, in the Bitcoin network, where someone tries to send a bitcoin transaction to two different recipients at the same time. However, once a bitcoin transaction is confirmed, it makes it nearly impossible to double spend it. The more confirmations that a particular transaction has, the harder it becomes to double spend the bitcoins.
is any money declared by a government to be to be valid for meeting a financial obligation, like USD or EUR.
The creation of an ongoing alternative version of the blockchain, by creating two blocks simultaneously on different parts of the network. This creates two parallel blockchains, where one of the two is the winning blockchain.
A measurement roughly equivalent to computational steps (for Ethereum). Every transaction is required to include a gas limit and a fee that it is willing to pay per gas; miners have the choice of including the transaction and collecting the fee or not. Every operation has a gas expenditure; for most operations it is ~3–10, although some expensive operations have expenditures up to 700 and a transaction itself has an expenditure of 21000.
Max number of computational units that the transaction should use up in the smart contrat execution.
The price per computational unit.
Go is a programming language created at Google in 2009 by Robert Griesemer, Rob Pike, and Ken Thompson.
The Go programming language.
Bitcoins have a finite supply, which makes them a scarce digital commodity. The total amount of bitcoins that will ever be issued is 21 million. The number of bitcoins generated per block is decreased 50% every four years. This is called "halving". The final halving will take place in the year 2140.
A change to the blockchain protocol that makes previously invalid blocks/transactions valid, and therefore requires all users to upgrade their clients.
The number of hashes that can be performed by a bitcoin miner in a given period of time (usually a second).
An HD Wallet, or Hierarchical Deterministic wallet, is a new-age digital wallet that automatically generates a hierarchical tree-like structure of private/public addresses (or keys), thereby addressing the problem of the user having to generate them on his own.
Initial Coin Offering
(ICO) is an event in which a new cryptocurrency sells advance tokens from its overall coinbase, in exchange for upfront capital. ICOs are frequently used for developers of a new cryptocurrency to raise capital.
The hashing algorithm used in Ethereum.
An append-only record store, where records are immutable and may hold more general information than financial records.
The process by which transactions are verified and added to a blockchain. This process of solving cryptographic problems using computing hardware also triggers the release of cryptocurrencies.
(multisig) addresses allow multiple parties to require more than one key to authorize a transaction. The needed number of signatures is agreed at the creation of the address. Multi signature addresses have a much greater resistance to theft.
Any computer that connects to the blockchain network.
A number only used once.
P2P stands for Peer to Peer.
Refers to the decentralized interactions that happen between at least two parties in a highly interconnected network. P2P participants deal directly with each other through a single mediation point.
Is a ledger where actors must have permission to access the ledger. Permissioned ledgers may have one or many owners. When a new record is added, the ledger’s integrity is checked by a limited consensus process. This is carried out by trusted actors — government departments or banks, for example — which makes maintaining a shared record much simpler that the consensus process used by unpermissioned ledgers.
A string of data that shows you have access to bitcoins in a specific wallet. Private keys can be thought of as a password; private keys must never be revealed to anyone but you, as they allow you to spend the bitcoins from your bitcoin wallet through a cryptographic signature.
Proof of Authority
A consensus mechanism in a private blockchain which essentially gives one client (or a specific number of clients) with one particular private key the right to make all of the blocks in the blockchain.
Proof of Stake
An alternative to the proof-of-work system, in which your existing stake in a cryptocurrency (the amount of that currency that you hold) is used to calculate the amount of that currency that you can mine.
Proof of Work
A system that ties mining capability to computational power. Blocks must be hashed, which is in itself an easy computational process, but an additional variable is added to the hashing process to make it more difficult. When a block is successfully hashed, the hashing must have taken some time and computational effort. Thus, a hashed block is considered proof of work.
Sets of formal rules describing how to transmit or exchange data, especially across a network.
A digital signature is a mathematical scheme for presenting the authenticity of digital messages or documents.
Contracts whose terms are recorded in a computer language instead of legal language. Smart contracts can be automatically executed by a computing system, such as a suitable distributed ledger system.
A change to the bitcoin protocol wherein only previously valid blocks/transactions are made invalid. Since old nodes will recognize the new blocks as valid, a softfork is backward-compatible. This kind of fork requires only a majority of the miners upgrading to enforce the new rules.
A method of encrypting text (cyphertext) in which a cryptographic key and algorithm are applied to each binary digit in a data stream, one bit at a time.
Decentralized file storage as part of Ethereum.
Is a digital identity for something that can be owned.
Refers to a distributed ledger that doesn’t require a native currency to operate.
Small fees imposed on some transactions sent across the bitcoin network. The transaction fee is awarded to the miner that successfully hashes the block containing the relevant transaction.
Blockchains that do not have a single owner; they cannot be owned. The purpose of an unpermissioned ledger is to allow anyone to contribute data to the ledger and for everyone in possession of the ledger to have identical copies.
A file that contains a collection of private keys.