The Memory Match Hall of Fame, kept the way Bitcoin keeps its ledger. Every verified game is a transaction signed with a key that lives in the player's browser. Transactions wait in a mempool until a player's browser finds a nonce whose block hash is below the target — proof-of-work — and the block is linked to the one before it. Difficulty retargets every 10 blocks toward 8 seconds of hashing; the miner earns a reward that halves every 210 blocks. Nothing here is edited afterwards. Don't trust — verify: the button below recomputes every hash, link, proof-of-work and signature in your own browser.
One site holds this chain, so a head hash is also published where the site can't rewrite it: the description of each week's Bitcoin Signal Processing video. If a hash here ever stops matching the chain, history was changed.
{type, game, ts, nick, addr, pub, moves, secs, board, moveLog, sig}. The server adds v (where it placed on the boards), placed and txid. sig is ECDSA P-256 / SHA-256 over the canonical JSON of the other fields; addr is the first 20 bytes of SHA-256(pub). A nickname belongs to the first address that signs it.{v, height, prev, merkle, time, tmpl, target, nonce, miner}; block hash = SHA256d(canonical header), and it must be numerically below target.tmpl is when the template was issued, time when it was solved.