NIST FIPS 204 (ML-DSA)
Signed build evidence has to outlive the hardware that produced it.
Why a lattice scheme
COODDEE's Regulated tier signs run evidence with ML-DSA rather than RSA or ECDSA. The reasoning is about lifetime, not fashion: a proof pack describing what a fleet built has to remain verifiable for as long as that artefact is in service.
A signature made today with P-256 has to still mean something years from now, against an adversary who has been recording. A lattice scheme is the standardised answer to that specific problem.
ML-DSA-65, deliberately
ML-DSA-65 is the parameter set, and it is not the highest available. It is the CNSA 2.0 selection — the level specified for national-security systems — chosen because a parameter set nobody else is using is a parameter set nobody else can verify.
Fail-closed by construction
The post-quantum backend has no fallback mode. When the pqc extra is absent the backend raises, the status reads Unavailable, and nothing is signed.
There is no degraded path that quietly signs with something weaker, because a signature that might be classical and might be post-quantum is a signature you cannot reason about. The board's PQ status panel reports that real state rather than a pinned value.
FIPS 204 names the algorithm COODDEE implements. FIPS 140-3 validation is a property of a cryptographic module in a specific configuration — see FedRAMP SC-13 for what the engine checks in your source.