Enum BackendId 

pub enum BackendId {
    UnauditedBlake3Standin,
    RiscZero,
    Unknown(u32),
}

Identifies which proof backend produced (and must verify) a ProofEnvelope.

This is a closed registry: BackendId::Unknown is the only variant that accepts arbitrary numeric ids, and it is the only variant that ProofEnvelope::validate_backend ever refuses. Every other variant is a backend this crate knows about by construction. Registering a new backend means adding a new named variant here — not widening what Unknown accepts.

Ratified decision D1 (2026-07-02, see GAP-REGISTRY.md VCG-001) selects RISC Zero as the production backend family. Lane VCG-001b registers the BackendId::RiscZero variant and a fail-closed verifier seam for it (see RiscZeroReceiptVerifier and ProofEnvelope::verify) — but does not vendor the risc0-zkvm crate or wire an actual cryptographic verify call. Per D1, the audited risc0 proving/verification toolchain is itself a reviewed-dependency supply-chain event that “carries the external audit budget”; adding it is out of scope until that review happens. Until then, BackendId::RiscZero is registered as AuditStatus::PendingExternalReview and always fails closed at verify-time.

Variants

UnauditedBlake3Standin

The crate’s existing unaudited blake3 “stand-in” cryptography (circuit.rs / snark.rs / stark.rs / zkml.rs). Gated behind the unaudited-pedagogical-proofs feature at verification time.

RiscZero

RISC Zero zkVM execution-receipt backend (ratified decision D1, 2026-07-02, GAP-REGISTRY.md VCG-001). This variant exists so envelopes can name the selected production backend family — it is the integration seam, not a working verifier. No external cryptographic review of the risc0 verify path has happened yet, so this backend is registered under AuditStatus::PendingExternalReview (never AuditStatus::ProductionReviewed) and ProofEnvelope::verify always fails closed for it. See RiscZeroReceiptVerifier for exactly where the audited risc0 verify call plugs in once review lands.

Unknown(u32)

An unrecognized or future backend id. Always fails closed in ProofEnvelope::validate_backend — this crate refuses to treat an id it does not recognize as valid, regardless of the numeric value.

Implementations

impl BackendId

pub const fn is_registered(&self) -> bool

Returns true for any of the crate’s registered known backend variants (i.e. not BackendId::Unknown).

Trait Implementations

impl Clone for BackendId

fn clone(&self) -> BackendId

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for BackendId

impl Debug for BackendId

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for BackendId

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for BackendId

impl PartialEq for BackendId

fn eq(&self, other: &BackendId) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for BackendId

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for BackendId