"""Synthetic byte-integrity exercise. No wallet files or network access."""
import hashlib
original = b"bitcoinlabz practice backup\n"
copy = bytes(original)
changed = original.replace(b"practice", b"Practice")
digest = lambda b: hashlib.sha256(b).hexdigest()
print("Original:", digest(original))
print("Copy matches:", digest(copy) == digest(original))
print("Changed matches:", digest(changed) == digest(original))
assert digest(copy) == digest(original)
assert digest(changed) != digest(original)