Nonce

A randomly-generated numerical value in cryptography used as an authentication protocol.

A nonce is an old term used in cryptography for a single purpose and one-time use. In the world of crypto, this string of numbers is used as a sort of validating evidence that the attached transaction has only been executed once. And this is possible because a nonce is generated randomly and is unique to each transaction. As a result, it is virtually impossible to use the same nonce twice, meaning that users on a blockchain network are prevented from ‘replaying’ transactions.

Nonces are also important parts of crypto mining. In fact, they are a critical component in hashing and consequently contribute to the level of mining difficulty on a network.