Consensus algorithm that combines Proof of Work and Proof of Stake. Ethereum is going to use Casper as a transition to Proof of Stake.

CDN (Content Delivery Network)

Allows for a quick transfer of digital media needed to load internet content (HTML, JavaScript, CSS, etc.) by storing copies in data centers across continents.

Centralized Ledger

A record of transactions which is maintained by the central agency/party/person.

Chain Linking

The process of connecting two blockchains with each other, thus allowing transactions between the chains to take place.


A program that initializes and manages a ledgers state through submitted applications. It is the Hyperledger Fabric equal to Smart Contracts.

Cloud Mining

Classical cryptocurrency mining requires huge investments in hardware and electricity. Cloud mining companies aim to make mining accessible to everybody. People just can log in to a website and invest money in the company which already has mining datacenters.

Cold Storage (Cold Wallet)

The offline safekeeping of private keys which allow for access to cryptocurrency funds. Typically this is done through hardware wallets, USB drives, and paper wallets.

Composer CLI

Hyperledger Fabric command line allowing for administrative tasks.

Composer Rest Server

Generates a rest server and associated API from a deployed blockchain that makes accessing data on blockchain easier by generating REST API service.


When a majority of participants of a network agree on the validity and order of a transaction inside the blockchain ledger.

Consensus Algorithm

The blockchain element that determines how consensus is reached on that blockchain. In other words; it is the part of the blockchain protocol that describes who gets to validate blocks of data (and thus is entitled to the reward) and how others can verify its legitimacy.

Consensus Point

A point – either in time, or defined in terms of a set number or volume of records to be added to the ledger – where peers meet to agree with the state of the ledger.

Consortium Blockchain

A blockchain where a pre-selected set of nodes handles the consensus process. It is also called a permissioned blockchain network that can be a hybrid model built between the trusted entity model of private blockchains and low trust provided by the public blockchain.


Also known as tokens, cryptocurrencies are representations of digital money.

Cryptographic Hash Function

A function that returns a unique big number that is commonly represented as fixed-length string. The returned string is unique for every unique input. Used to create a “digital ID” or “digital thumbprint” of an input data(bits).


The encryption and decryption of data. There are two main cryptographic concepts used in the blockchain – Hashing and Digital Signatures. In general, there are three forms of encryption that are widely used – symmetric cryptography, asymmetric cryptography, and hashing.


An unauthorized use of a device owned by others, to mine cryptocurrency. The first widely known attempt for cryptojacking was the torrent tracker Piratebay. They enabled an in-browser mining software, so when somebody visits the website, his/her computer will start mining cryptocurrency via the browser with no indication of it happening.