Validator

A validator is a node with the right and the duty to take part in consensus. It proposes new blocks, checks blocks proposed by others against the protocol rules, and signs the ones it accepts. On a proof-of-authority chain like this one, the validator set is a known list of identified signers rather than an open mining or staking market, so agreement comes from counted signatures, not from computational work.

Chain 2800 runs QBFT consensus with ten validators and a block roughly every 0.62 s (500 ms target). A block is committed only when seven of the ten validators sign it; that commit is what gives the chain its finality, since on a validator a committed block is not replaced by a competing branch; from block 25,080,000 (AIP-22 stage 5) a node outside consensus treats a block as final once the next anchor covers it, which is the finalized block, at most one anchor interval (32 blocks, about 20 seconds) behind the head. Since block 25,080,000 (AIP-22 stage 5) headers no longer carry ECDSA commit seals and, since block 24,300,000 (AIP-22 stage 4), every vote counts only with the verified post-quantum seal of its author, and a commit still carries the ECDSA commit seal of its validator as an additional check; the chain calls that post-quantum consensus, with three limits: the transport between nodes is still authenticated by secp256k1, the ten validators are run by one operator, and no third party has audited it yet.

Each validator also holds a Falcon-512 key (and, since 2026-09-03, an SLH-DSA-SHA2-128s key), one of the 10 entries (9 until 2026-09-11) of the signer registry, committed on chain for the epochs up to the one of block 18,082,816; the epoch in force since block 20,836,228 is pinned by its hash in the node configuration. Since block 13,014,000, every anchor block header (every 32nd block; every 128th from 17,225,968 to 20,746,736) carries a seal certificate of validator post-quantum signatures (Falcon-512 at every anchor and, since 2026-09-04, SLH-DSA-SHA2-128s as a second, hash-based scheme, every 128th block since 2026-09-29) over the parent block, at least 7 per scheme today (3 until 2026-08-21, 6 until block 20,715,632 on 2026-09-29) and in practice 8 to 10, and a 32-byte digest of that certificate sits inside the data covered by the block hash. That mechanism is the post-quantum anchor.

Since 2026-09-11 one of the ten validators runs a second, independently implemented client (Nethermind) and the other nine run Hyperledger Besu, so every block is also checked by a second codebase; with nine of the ten on one client, more than the quorum of seven, the second client cannot on its own stop a block the other nine agree on. See client diversity.