Chapter 15: Blockchain and Bitcoin Mining Architectures

Exercise 1

Visit the blockchain explorer at https://bitaps.com and locate the list of last blocks on that page. Click on a block number and you will be presented with a display containing the hexadecimal listing of the block header along with its SHA-256 hash. Copy both items and write a program to determine if the hash provided is the correct hash of the header. Remember to perform SHA-256 twice to compute the header hash.

Answer

The Python file Ex__1_compute_block_hash.py contains the block header hashing code:

#!/usr/bin/env python
"""Ex__1_compute_block_hash.py: Answer to Ch 15 Ex 1."""
# This is a solution for Bitcoin block 711735
# See https://bitaps.com/711735
import binascii
import hashlib    
# The block header copied from bitaps.com
header = '00000020505424e0dc22a7fb1598d3a048a31957315f' + \
    '737ec0d00b0000000000000000005f7fbc00ac45edd1f6ca7' + \...