The QBFT message layers move under post-quantum seals one layer at a time, each armed at a block height. This page says which layers are in force.
The schedule
| Layer | Height | Status |
|---|---|---|
| Commit | 17,250,000 | In force |
| Proposal | 17,400,000 | Armed, not yet reached at height 17,395,409 on 2026-09-06 |
| Round change | 17,550,000 | Armed |
| Prepare | 17,700,000 | Armed |
"Armed" means every node carries the rule and the height, and the rule begins to apply when the chain reaches it. Read the current height from any endpoint and compare; do not trust this table to be fresh.
Why one layer at a time
A hash-based post-quantum signature costs seconds, and this chain produces a block every half second. Measured: putting SLH-DSA-SHA2-128s on every commit message took a test network from 0.5 to 4 seconds per block. Enforcing all four layers at once would not have been a stricter chain, it would have been a stopped one.
Layering also means each step can be observed on the live chain before the next is armed: after the commit layer came into force, the measurement was nine of nine validators, zero rejections, zero round changes, and block rate inside its normal band.
Why heights and not timestamps
Every AERE rule activates on a block number, delivered through per-node system properties rather than through genesis. That is a deliberate choice for a chain whose validator set is small enough to coordinate, and it has a real cost: two nodes with different heights do not agree on what a valid header is, and nothing in the protocol makes them agree.
The mitigation is procedural rather than cryptographic: uniformity across the fleet is measured, and a split configuration is treated as an open defect. If you run a node, this is the reason the configuration page tells you to take the options from a live node rather than write them by hand. See Configure.
Coordinated postponement is the safe move
If a milestone has to be moved, it is moved on every node before the height, not disarmed on one. A node that validates differently from its neighbours does not fail loudly; it goes quiet, or it forks. Ethereum postponed Constantinople by 200,000 blocks a day before activation, and that remains the right shape for a chain that is already running.