What Is “Extranonce” and Why Is It Necessary in Bitcoin Mining?
Extranonce is a field within the Coinbase transaction of a block, which is part of the Merkle Root. It is used as an additional variable to iterate through when the primary 32-bit nonce in the block header is exhausted.
Since the hash rate is so high, the extranonce allows miners to change the Merkle Root, thus opening up a massive new range of hash possibilities.
Glossar
Coinbase Transaction
Definition ⎊ Coinbase Transaction refers to a specific type of on-chain movement or exchange instruction originating from or destined for the infrastructure managed by the Coinbase entity.
Block Header
Genesis ⎊ A block header, fundamentally, encapsulates metadata pertaining to a specific block within a blockchain; it serves as the block’s identifying signature and is critical for maintaining chain integrity.
Extranonce
Definition ⎊ Extranonce is a variable field included in certain cryptocurrency mining communication protocols, allowing miners to rapidly adjust block header data to find a valid nonce without reprocessing the entire transaction set.