glossary.

Much like a URL, a blockchain address is the location to or from which transactions occur on the blockchain.

Any coin or token other than Bitcoin.

A register or account book created for the purpose of providing support/evidence of individual transactions. Normally, an attestation ledger is used to verify that a transaction has been carried out, or to verify the authenticity of products or transactions.

The first and most popular cryptocurrency based on DLT technology developed from a whitepaper written by Satoshi Nakamoto in 2008.

A group of transactions entered into a blockchain; analogous to a page of a ledger or record book.

A mathematical structure for storing digital transactions or data in an immutable, distributed, decentralized digital ledger consisting of blocks that are linked via cryptographic signature that is nearly impossible to fake, hack or disrupt.

A blockchain that resides on a private network of computers that is only accessible to those with permission.

A blockchain that resides on a network of computers around the world that is accessible to everyone.

A property of a distributed, decentralized system to resist complete failure even when some of the nodes fail or act maliciously.

A system or process for which there is a singular (i.e., central) source of authority, control and/or truth.

The entire chain of documentation of ownership of a product during its lifecycle from raw materials to the final end user.

Another name for a smart contract.

PoA is an alternative form to the PoS algorithm. Instead of staking cryptocurrency (wealth), in PoA you stake your identity. This means voluntarily disclosing who you are in exchange for the right to validate blocks. Any malicious actions you undertake as a validator will reflect back on your identity. PoA blockchains require a thorough form of KYC (Know Your Customer - a verification process that determines you actually are who you claim to be).

PoB allows the miners to “burn” or destroy cryptocurrency which grants them the right to add blocks in proportion to the coins destroyed. Essentially, miners burn coins/tokens to buy virtual mining rigs that give them the power to mine blocks. The more currency burned by the miner, the bigger the ensuing virtual mining rig. To burn, miners send currency to a verifiably un-spendable address. This process does not consume many resources, thus PoB is often called PoW without energy waste.

Depending upon the implementation, miners are allowed to burn the native currency or the currency of an alternative chain, and in exchange, they receive a reward in the native currency of the blockchain.

PoC allows the mining devices in the network to use their available hard drive space to decide the mining rights, instead of using the mining device’s computing power (as in PoW) or the miner’s stake in the cryptocurrency (as in PoS).

In PoS, miners put up(i.e., “stake”) some of the blockchain’s cryptocurrency (e.g., ether for the Ethereum blockchain) in order to increase their chances of being selected to validate a block. The stake is locked up as a deposit to ensure the miner validates the block according to the rules. If the miner violates the rules, the deposit will be “burned” or destroyed. PoS is less resource intensive than PoW since fewer miners are racing to solve the mathematical formula.

In PoW, transaction data (block) + a random strings of digits (nonce of block) are repeatedly applied to a (hashing) mathematical formula by miners, until a desirable outcome is found (the proof of work). Other miners then verify the proof of work by taking the alleged input string and applying it to the same formula to see if theoutcomeisindeedthatwhatwaspresented. Iftheresultsare the same, the transaction is verified and added to the blockchain. As many miners are racing to solve the formula which requires a great deal of computing power, PoW is resource intensive.

The process used to validate a transaction across a distributed blockchain network designed to achieve Byzantine Fault Tolerance.

Digital money which uses encryption and consensus algorithms to regulate the generation of coins/tokens and transfer of funds. Cryptocurrencies are generally decentralized, operating independently of central authorities.

The science of securing communication using individualized codes so only the participating parties can read the messages.

A governance structure without a central authority which rewards good behavior and penalizes bad behavior by a set of pre-defined rules which can only be changes by a vote, which typically requires a stake, adding risk to the process to discourage bad actors, amongst the participants.

Software which does not rely on a central system or database but can share information amongst its users via a decentralized database, such as a blockchain.

A system with no single point where the decision is made. Every node makes a decision for its own behavior and the resulting system behavior is the aggregate response.

The network or Internet equivalent to the real identity of a person or entity (like a business or government agency). Advocates of blockchain-based digital identity is to return ownership and control of personal information to the individuals. In any given transaction, personal information is not disclosed, but rather the information required by one party is verified by the digital identity application.

A mathematical scheme for verifying digital messages or documents satisfy two requirements - they have authenticity (from a known sender) and integrity (were not altered in transit.

In order to increase security, multisig addresses require more than one digital signature (and therefore multiple keys) to sign a transaction or message.

A digital signature that can be performed by any of a group of people that each have keys. A property of a ring signature is that it is impossible to determine which of the group signed the transaction.

As opposed to decentralized, a distributed system shares processing and/or data across multiple nodes, but the decisions may still be centralized and use complete system knowledge.

The larger class of technology of which blockchain is a subset. A digital system for recording the transaction of assets in which the transactions and their details are recorded in multiple identical copies at the same time with no central data store or administration.

A unique problem to cryptocurrency where the same coins or tokens are spent or traded twice.

A public blockchain that supports smart contracts.

Legal tender the value for which is backed by a government or governmental body (e.g., US dollars, Euros)

A collectively agreed upon software update by all nodes in a distributed network. Sometimes, the previous version continues in parallel with the new version.

The property an item of being exchangeable with other like items. For example, USD and Euros are fungible. The value of USD can be expressed in Euros.

A fee charged to write a transaction to a public blockchain. The gas is used to reward the miner which validates the transaction.

The first or first few blocks of a blockchain.

Establishment of policies and continuous monitoring of their proper implementation of an organization or system.

A function that receives an input of any size and returns a unique string of a uniform length.

IBM’s private (permissioned) blockchain toolset.

The information on an entity used by computer systems to uniquely represent a person, organization, application, or device.

The property of being unchangeable. Once a transaction has been added to a block and written to a blockchain, it cannot be changed and therefore is immutable.

The first sale of a blockchain coin or token.

The ability of two or more systems to communicate and exchange data. Due to various design decisions (e.g., consensus protocol) most blockchains are not interoperable, however there are many projects that are working to connect various blockchains.

A peer-to-peer hypermedia protocol for storing and sharing data in a distributed file system using content-addressing to uniquely identify each file in a global namespace connecting all computing devices.

The legal process of a business identifying and verifying the identity of its clients. KYC requirements vary from jurisdiction to jurisdiction.

The ease of converting an asset (or, in this case, cryptocurrency) to cash (fiat).

The production version of a blockchain.

In cryptography and computer science, a Merkle or hash tree is a tree in which every leaf node is labeled with the hash of a data block, and every non-leaf node is labeled with the cryptographic hash of the labels of its child nodes.

In a public blockchain, the process of verifying a transaction and writing it to the blockchain for which the successful miner is rewarded in the cryptocurrency of the blockchain.

A computer which holds a copy of the blockchain ledger.

The property an item of not being exchangeable with other like items. For example, USD and Euros are fungible. For example, a Stratovarius violin is non-fungible because the value of it cannot be expressed in a number of other violins.

Data stored external to the blockchain.

Data stored within the blockchain.

Software products that include permission to use, enhance, reuse or modify the source code, design documents, or content of the product.

An application that connects blockchain applications to legacy applications.

A direct connection between two participants in a system - can be computer to computer or person to person.

The entire history of a product during its lifecycle including its chain of custody and all documentation of value added services and activities which were used to produce that product or service.

A public key is a unique string of characters derived from a private key which is used to encrypt a message or data. The private key is used to decrypt the message or data.

The name used by the person or entity 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.

A random sequence of words which can be used to restore a lost wallet.

A type of database partitioning that separates very large databases the into smaller, faster, more easily managed parts called data shards. Sharding can potentially be used to improve blockchain performance.

A discrete blockchain that is linked to a main blockchain via two-way pegs which enable assets to be interchanged between the main blockchain and the sidechain. Sidechains are a method to enable scaling and increase transaction speed by only performing necessary transactions on the main blockchain.

Self-executing computer code deployed on a blockchain to perform a function, often, but not always, the exchange of value between a buyer and a seller.

A JavaScript-like object-oriented programming language for Ethereum for implementing smart contracts on the Ethereum blockchain.

A cryptocurrency which is underwritten by an asset or assets (e.g., fiat currency, commodities, etc.) designed to minimize the volatility of the price of the coin/token.

A process by which blockchain transactions are executed off- chain, collected and then written to the main chain as a single transaction in order to improve performance and reduce cost.

A staging blockchain environment for testing application before being put into production (or onto the mainnet).

Cryptographic tokens represent programmable assets or access rights, managed by a smart contract and an underlying distributed ledger. They are accessible only by the person who has the private key for that address and can only be signed using this private key.

The creation and first sale of a blockchain coin or token.

A type of fungible Ethereum token (i.e., smart contract) standard which is defined by a series of functions that must be supported, including functions to retrieve the total supply, transfer from one wallet to another, and approve a transaction. Typically, any given ERC-20 token has many copies which are held in a variety of crypto wallets.

A type of non-fungible Ethereum token (i.e., smart contract) standard which is defined by a series of functions that must be supported, including functions to retrieve the total supply, transfer from one wallet to another, and approve a transaction. Each ERC-721 token is unique and non-interchangeable with other tokens (i.e., non-fungible).

An application to buy, sell and trade cryptocurrencies.

A ledger that doesn’t require a native currency to operate.

The study, design and implementation of monetary management and distribution based on blockchain technology.

A measurement of the speed of a blockchain. The low TPS of most blockchains is a significant barrier to using blockchain for business, especially financial, applications.

A primary property of public blockchains whereby any participant in a system or transaction can view the transactions on the blockchain.

Confidence in the integrity of an entity (e.g., person, organization, etc.).

The elimination of trust from a transaction. Blockchain is called a trustless system because the two entities performing a transaction do not need to trust one another. The properties of blockchain - digital signatures, cryptography, etc. - provide the trust.

A digital file that holds coins and tokens held by the owner. The wallet also has a blockchain address to which transactions can be sent.

A wallet disconnected from the internet.

A wallet connected to the Internet.

A wallet that requires multiple digital signatures to execute a transaction.