Aquí está el bloque de génesis con su hash. ¿Cómo se calculó el hash?
{
"hash":"000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f",
"ver":1,
"prev_block":"0000000000000000000000000000000000000000000000000000000000000000",
"mrkl_root":"4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b",
"time":1231006505,
"bits":486604799,
"nonce":2083236893,
"n_tx":1,
"size":285,
"tx":[
{
"hash":"4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b",
"ver":1,
"vin_sz":1,
"vout_sz":1,
"lock_time":0,
"size":204,
"in":[
{
"prev_out":{
"hash":"0000000000000000000000000000000000000000000000000000000000000000",
"n":4294967295
},
"coinbase":"04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73"
}
],
"out":[
{
"value":"50.00000000",
"scriptPubKey":"04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f OP_CHECKSIG"
}
]
}
],
"mrkl_tree":[
"4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"
]
}
Como se describe en la página wiki sobre hash de bloque , el hash 2xSHA256 se toma solo del encabezado del bloque (no de las transacciones en él): 80 bytes, que consisten en la versión, hash de bloque anterior, tx merkle root, tiempo, bits y nonce.
Cita directa de esa página:
>>> 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'