Supply-chain provenance

Supply-chain provenance is the problem of proving that an artifact (a physical product, a software binary, a document) went through a specific sequence of authorized steps. Each step — manufacturer, distributor, regulator, retailer — can sign an attestation. The result is a chain of signatures that a consumer can verify.

What you get

  • Every step in the supply chain produces a signed attestation anchored in a public transparency log.
  • Consumers (or regulators) can verify the full chain from raw material to finished product.
  • Any tampering — a missing step, an unauthorized actor, a backdated signature — is cryptographically detectable.
  • Quorum policies apply per step: “manufacturing step requires 2-of-3 line managers; QA step requires 3-of-5 inspectors”.

Deployment shape

[ Manufacturer ] --attestation--> [ Step 1 ] ----+
[ QA lab ]      --attestation--> [ Step 2 ] ----+
[ Distributor ] --attestation--> [ Step 3 ] ----+
[ Retailer ]    --attestation--> [ Step 4 ] ----+
                                                  |
                                                  v
                                          [ Transparency log ]
                                                  |
                                                  v
                                       [ Consumer / regulator verifies ]

Each step includes:

  • Artifact hash (what was produced / inspected / shipped).
  • Actor identity (manufacturer, lab, distributor).
  • Timestamp (when the step happened).
  • Location (where the step happened).
  • Quorum signature (T-of-N threshold).

The transparency log records every step. Inclusion proofs let any consumer verify their product’s history against the public log.

Combining with composite signatures

Supply-chain signatures are long-lived (a product’s history should be verifiable for its entire lifespan, potentially decades). This makes them a prime candidate for PQ migration via composite signatures. Each step’s signature can carry both classical and PQ components from day one of deployment.

Attribute-based policies

Real supply chains have policy nuance:

  • “Manufacturing must occur in region X.”
  • “QA inspection must come from an accredited lab in jurisdiction Y.”
  • “Distribution step requires 2-of-3 line managers.”

The attribute-based threshold DSL expresses these policies; the coordinator enforces them.

When to choose this use case

  • You’re a manufacturer tracking components through a multi-stage production process.
  • You’re a regulator verifying that products went through required inspections.
  • You’re a consumer (or consumer-facing service) that needs to verify provenance claims.

See also