The following table depicts the structure of a block header:
Field |
Size |
Description |
Version |
4 bytes |
The block version number that dictates the block validation rules to follow. |
Previous block's header hash |
32 bytes |
This is a double SHA-256 hash of the previous block's header. |
Merkle root hash |
32 bytes |
This is a double SHA-256 hash of the Merkle tree of all transactions included in the block. |
Timestamp |
4 bytes |
This field contains the approximate creation time of the block in the Unix epoch time format. More precisely, this is the time when the miner has started hashing the header. (The time from the miner's point of view.) |
Difficulty target |
4 bytes |
This is the ... |