Falcon-512

Falcon-512 is a digital signature scheme built on NTRU lattices, one of the schemes selected by NIST for post-quantum standardization and the basis of the FN-DSA draft standard. Its security does not rest on the elliptic-curve discrete logarithm problem, so Shor's algorithm, the quantum attack that breaks that problem, does not apply to it. Among post-quantum schemes it is notable for compact signatures and fast verification. Signatures are compressed, so their exact length varies slightly from one signature to the next.

On chain 2800, Falcon-512 plays two distinct roles, and the distinction matters.

First, as a precompile: Falcon-512 verification has been callable from any contract since block 9,189,161, as one of five post-quantum precompiles at addresses 0x0AE1 through 0x0AE5, validated against NIST test vectors on-chain.

Second, in the post-quantum anchor: since block 13,014,000, every 32nd block header carries a certificate of Falcon-512 signatures from the validators over the parent block, and a 32-byte digest of that certificate sits inside the data covered by the block hash. The enforced threshold today is at least 3 signatures per anchor block; in practice certificates carry 5, the configured cap. The validators' Falcon-512 public keys are bound on-chain in a 9-entry signer registry held by an immutable contract whose storage holds the registry's keccak hash.

Equally important is what Falcon-512 does not do today: the consensus signatures that give blocks finality remain classical ECDSA secp256k1 under QBFT. The anchor gives block history a signature layer designed to withstand quantum attack; it does not make the consensus itself post-quantum, and the chain does not claim that it does.