# HMAC va xabar haqiqiyligi
# Faqat sintetik, lokal o‘quv misoli.

import hmac
key = b"training-key-only"
tag = hmac.digest(key, b"amount=10", "sha256")
changed = hmac.digest(key, b"amount=11", "sha256")
print(hmac.compare_digest(tag, changed))