CUCaTS
Puzzlehunt 2014
h(x) = 516696d7a1d27054ee98fe7272163ce5f80f3e1b676e66ff996a435aba9f74f4
author: unknown
h(x) looks like a cryptographic hash, and refreshing the page shows it changes every 5s. We find that the SHA256 hash of the unix time (floored by 5 seconds) gives us the same hash. Thus the answer is the current unix time (and values within ± a minute are accepted).