Glossary

Permissioned

Said of a blockchain in which participation is not open to everybody – participants are known and have defined roles that set how they can interact with the blockchain (for instance limiting who can validate transactions, or who can submit them).

October 27, 2018

Permissionless

Said of a blockchain in which participants have no restrictions imposed on them, i.e. every participant can perform the same actions as the others (for instance validating blocks). Examples include public blockchains such as Bitcoin or Ethereum, in which nobody...

October 27, 2018

Private blockchain

A blockchain system with controlled access, in which participants are limited to those who are known and trusted (e.g. people in a particular industry or organization).

July 14, 2018

Proof of Authority

PoA is a consensus mechanism in which consensus is set by a number of pre-selected validators, who are usually  These “authority” comes from them being thoroughly vetted before being accepted as validators, having to satisfy very stringent requirements (such as...

July 14, 2018

Proof of Stake

A consensus mechanism in which validators are chosen based on the number of coins or tokens they offer as collateral to prove their good intentions. There are different types, but in general a bigger stake will result in being able...

July 14, 2018

Proof of Work

Proof of Work (PoW) consensus is the original consensus algorithm, made popular by Bitcoin. Validators (known as “miners”) race to solve a computational puzzle, and who wins gets to decide which transactions are included in the next block of the...

July 14, 2018

Public blockchain

A blockchain platform or system that anyone can access. Bitcoin and Ethereum are examples of a public blockchain.

July 14, 2018