Definition
A nonce is a number or value that can only be used once, often found on authentication protocols and cryptographic hash functions. In blockchain technology, nonce is a pseudo-random number that is utilized as a counter during the mining process.
Understanding the term
Nonce is the short form of the phrase “number used only once,” represented by a four-bit number added to an encrypted or hashed block in a blockchain. When rehashed, it meets the difficulty level restrictions. Miners look to solve the nonce for the process to be successful. When the solution is found, miners receive block rewards.
Within Bitcoin (as well as most proof-of-work systems), a nonce is just a random number. Here, miners follow a trial and error approach in which every calculation takes a new nonce since the probability of guessing the nonce is close to zero. A nonce can be categorized based on how it is generated. A random nonce is produced by stringing random numbers together.
Takeaway
The term “nonce” refers to the number a blockchain miner requires to solve for a block in the blockchain. Once solved, the miner receives the block reward. Miners can open new blocks by generating a nonce that makes the hash they create less than the hash of the block the miners are validating.