Hi, I want to learn exact formula to get blocks hash where nonce is compatible for network's target requirements.
For example, I want to see formula like this.
SHA256 ("Previous Block Hash + Nonce + Merkel Root + Client Version")
Thank you very much. Have a great day
This is what you are looking for:
A block header contains these fields:
Field Purpose Updated when... Size (Bytes)
Version Block version number You upgrade the software and it specifies a new version 4
hashPrevBlock 256-bit hash of the previous block header A new block comes in 32
hashMerkleRoot 256-bit hash based on all of the transactions in the block A transaction is accepted 32
Time Current timestamp as seconds since 1970-01-01T00:00 UTC Every few seconds 4
Bits Current target in compact format The difficulty is adjusted 4
Nonce 32-bit number (starts at 0) A hash is tried (increments) 4
For example, this python code will calculate the hash of the block with the smallest hash as of June 2011, Block 125552. The header is built from the six fields described above, concatenated together as little-endian values in hex notation:
>>> import hashlib
>>> header_hex = ("01000000" +
"81cd02ab7e569e8bcd9317e2fe99f2de44d49ab2b8851ba4a308000000000000" +
"e320b6c2fffc8d750423db8b1eb942ae710e951ed797f7affc8892b0f1fc122b" +
"c7f5d74d" +
"f2b9441a" +
"42a14695")
>>> header_bin = header_hex.decode('hex')
>>> hash = hashlib.sha256(hashlib.sha256(header_bin).digest()).digest()
>>> hash.encode('hex_codec')
'1dbd981fe6985776b644b173a4d0385ddc1aa2a829688d1e0000000000000000'
>>> hash[::-1].encode('hex_codec')
'00000000000000001e8d6829a8a21adc5d38d0a473b144b6765798e61f98bd1d'
Source:
https://en.bitcoin.it/wiki/Block_hashing_algorithm
