If you are looking to prove that something happened after a certain timestamp, you can use a randomness beacon[0]. Every <interval>, the beacon outputs a long r

If you are looking to prove that something happened after a certain timestamp, you can use a randomness beacon[0]. Every <interval>, the beacon outputs a long random number. Include the timestamped random number into your artifact. You are relying upon the authority of the beacon to be random, but good practice is to utilize multiple independent beacons. [0] https://csrc.nist.gov/projects/interoperable-randomness-beacons https://csrc.nist.gov/projects/interoperable-randomness-beac...