Chained-forward UUID5 (SHA-1) hashing in Python. The next hash is based on the previous hash and the current epoch, making it nearly impossible to edit.

chained_hashing.py

#!/usr/bin/python3

import uuid
import time


def makeUUID(text, start=False):
    if start:
        return uuid.uuid4()  # random uuid to begin with
    timestamp = time.time()
    return uuid.uuid5(uuid.NAMESPACE_URL, f"{text}{timestamp}")  # each new uuid is based on the one before it, plus a now timestamp


"""
# base key -> key 1 -> key 2
# base key is random uuid4
# key 1 is uuid5 based on base key and epoch
# key 2 is uuid5 based on key 1 and epoch
# key 3 is uuid5 based on key 2 and epoch
# etc.

# Would have to reverse SHA-1 encryption on key 3 to get {key2}{epoch},
# then reverse SHA-1 encryption on key 2 to get {key1}{epoch}
# etc.

# Changing key1 (plus change in epoch) would change key 2, which (plus change in epoch),
# would change key 3, etc. Can't change an older key without a domino effect to the future keys.
"""

all_keys = []
new_key = None
old_key = makeUUID(text=None, start=True)
for i in range(0, 10):
    new_key = makeUUID(text=f"{old_key}")
    print(new_key)
    all_keys.append(new_key)
    old_key = new_key