Algorithms · LESSON 9
Seal draw materials — changes are caught
Seal the participants and the draw settings (winners per rank) with a hash in advance, and any secret change makes the hash differ and is exposed at once.
Step 1
Draw settings (winners per rank)
e.g. set how many to pick per rank, like 1 for 1st, 3 for 2nd.
Step 2
Entrant info (enter participants)
Step 3
Seal
Press "Seal" to stamp the draw settings and the entrant info each with its own hash. Keep just those two hashes and you are done.
Keep the two hashes separately, and later just re-hash each file and check it matches — you can even tell which side was tampered.
Sealed information can be checked anytime on each host's draw-ledger page. A host can compare the seal hash of a draw they ran for themselves.
Step 4
Tamper check
Compare the sealed hash with the current data's hash. Try both below.
① Check as-isPress "Tamper check" without changing anything → the hash matches, so it passes!
② Check after changingChange the draw settings or entrants a bit in steps 1–2, then press "Tamper check" → the hash differs, so it's caught!