Proof of History
dPOH is a SHA-256 hash chain that advances whether or not anything happens. Each tick hashes the one before it, so the number of ticks between two events is itself a proof that time passed — and the ordering inside a slot is settled before consensus ever votes on it. This is the one thing on Kortana that has no Ethereum equivalent.
Progress through epoch 257
11.33% · the validator set is fixed for the whole epoch, so it changes only when this fills (§24.1)
Current tick
A checkpoint is where the chain records the tick hash so a verifier can resume from it instead of replaying from genesis. The sequence above is the authority on ordering — two events in the same slot are ordered by their ticks, which is settled before any vote is cast.
