If, in Bitcoin, the nonce is included in the header of the proposed block, is it the answer to the puzzle from the previous block?
Nonce of a header is the answer to that block.
Recall the mining process:
- Create a template block header
- Choose a nonce
- Hash the block header
- If the hash is lower than network difficulty, broadcast it. Else, choose a different nonce.
To sum up, nonces are for individual blocks, and a different nonce is chosen until the template becomes a valid block.
The header of block consists of:
- Previous Hash
- Time stamp
- Current Hash
The Current Hash always points to Previous Hash in set of mined blocks. Miners collect all transactions in pool and add it to block. The task of miner is to find Nonce in equation.And hash the final answer which is obtained.
A = Hash(B || z) where A and B are known. Task is to find "z".
If it's correct then it will be considered as valid block and added to blockchain. And reward for that block is generated and miner will send the message across the nodes regarding the valid block.