A second computer checks our log every hour, the same way any stranger could, and raises the alarm if anything's off.
Our log can prove nobody tampered with it, but only if someone actually checks. The monitor is that someone. It runs every hour on a machine that doesn't host the log, and it reads the same public pages you would.
The latest state has to carry the log's signature. Anything the log didn't sign gets thrown out.
Seven independent witnesses we trust each sign the log's state, and the monitor checks every signature. Fewer than four good ones, or any bad one, sets off an alarm. Two more witnesses, gblin.digital and whisper.online, also sign. We check them and show them, but they aren't on our signed list of trusted witnesses, so they don't count toward the four.
It checks a proof that the new log starts with exactly the old one. A rewrite, a fork or a rollback fails here.
It re-hashes every record the log serves and checks that they add up to the signed state. If a record was changed or dropped, the math won't match.
It watches for certain keys. If one shows up in a record its owner didn't make, that's the earliest sign the key was stolen.
A log that froze, or a stale copy someone keeps showing you, can look perfectly valid. The monitor catches that by checking how old the newest witness signature is.
Witnesses check the log when it writes, and they refuse to sign a fork. The monitor checks what the log shows readers afterwards, which the witnesses never see. Between them, both sides are covered. The monitor only moves forward to a new state that passes every check. If one fails, it stops and raises the alarm instead of carrying on.
It checks every signature on the log's state: the log's own two (a regular Ed25519 one and a post-quantum ML-DSA-44 one), the seven witnesses, and the two witnesses that also sign post-quantum. Only the seven regular witness signatures count toward the four. A bad post-quantum signature still sets off an alarm, but a good one can't stand in for a missing witness.
Two copies run. One is on a different machine at the same hosting company as the log. The other is on our own hardware on a different network, so one provider can't knock both out or feed both the same fake view. We run both. A copy run by someone unrelated to us would be stronger, and anyone can run the same checks against the public pages.
A match on a watched record means the bytes matched. It doesn't mean what the record says is true.
Everything the monitor reads is public: the log's state, the witness signatures, the proofs and the records themselves. The log is also published as static tiles you can copy and recompute end to end.