Nonce
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- Only blocks whose hashes start with a certain number of 0’s can be added to the ledger. Why?
- The idea is to create competition among the miner. Who will find the number that will contain a run of leading zeros below the difficulty target first. Remember the SHA256 hash is unpredictable.
- Thus, the miners has to add an arbitrary number to the block, known as nonce (i.e. 9876879).
- Finding the a block with a certain number of 0’s is a brute force task, and can only be achieved by testing different combinations as fast as possible (lots of random guesses/trail and error – which keeps it fair).
- Hash value is unique for the combination of a nonce and input date
- The guessing game is called ‘hashing’.