Mainnet · 9002
head1,617,157

Proof of History

The verifiable clock

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.

Sequence
970,293,600,036
ticks since genesis
Ticks per slot
64
1,500 ms slot
Checkpoint every
4,096
3,876 since the last
Epoch
673
1,957 / 2,400 slots

Progress through epoch 673

81.54% · the validator set is fixed for the whole epoch, so it changes only when this fills (§24.1)

Current tick

Hash0x536c5cc3d3f3ed96820a19fee9273d55e0432c6ab85575be59fb169dbcba4c39
Sequence970,293,600,036
Checkpoint every4,096 ticks · 3,876 since the last one
Slot1,617,157 · reported by the node, not derived from the sequence

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.