CPHAR is not a zero-knowledge protocol. It is a hardware-backed attestation pattern. Zero-knowledge proofs are an optional add-on that let a prover make aggregate reserve claims without revealing per-lot fields.
What a ZK reserve claim looks like
The prover assembles per-seal attestations as before, then constructs a circuit that:
- Verifies each seal's signature against its registered public key.
- Checks that each lot commitment appears in the pinned registry snapshot.
- Asserts the aggregate property (e.g.
sum(masses) ≥ threshold). - Asserts that no two commitments are equal.
The prover publishes the resulting proof alongside the snapshot commitment and the public threshold.
Example claim
The verifier learns only: (a) the threshold holds, (b) which snapshot was used, and (c) the proof is valid. Individual seal_id values, lot commitments, and warehouse locations remain private.
Assumptions
What this does not prove
- ZK does not strengthen the underlying hardware attestation. A ZK proof over weak seal evidence is still weak evidence.
- ZK does not prove disclosure completeness — it only hides per-lot fields.
- ZK does not replace audit. The auditor still needs registry visibility and inspection records.