Evidence Stitching
Evidence stitching is the process of assembling a coherent, verified artefact from partial evidence that arrives from multiple independent sources — without a central coordinator and without any single source having a complete view.
This is the mechanism defined in P18 and P19.
The problem
A compliance claim for a global enterprise may require evidence from:
- Legal teams in three jurisdictions
- A third-party auditor
- A cloud infrastructure provider
- A hardware attestation service
Each source holds one piece. No single source holds all pieces. A central coordinator that waits to collect all pieces before assembling the artefact is a bottleneck and a single point of failure.
More importantly, requiring every source to publish to a central collector breaks the decentralised, publisher-controlled model that AIEP is built on. Each source should publish to its own Mirror. Assembly should happen later, by any party with access to the partials.
How stitching works
| Step | What happens |
|---|---|
| 1 | Each source publishes a PARTIAL_EVIDENCE artefact to its own Mirror |
| 2 | Each partial carries: stitch_id (shared identifier), partial_index (position), partial_hash, source_id |
| 3 | A stitching agent discovers all partials with the same stitch_id by querying the registry |
| 4 | The agent verifies each partial: schema conformance + hash integrity + issuer signature |
| 5 | Partials are assembled in partial_index order |
| 6 | The agent computes the stitch_hash — SHA-256 over the concatenated canonical partials in index order |
| 7 | The assembled artefact is published with stitch_hash and the full array of partial_hashes |
| 8 | Any third party can re-verify by re-fetching the partials and recomputing the stitch_hash |
Stitching properties
| Property | Detail |
|---|---|
| No central coordinator | Each source publishes independently; assembly can happen later by any party |
| Order-independent arrival | partial_index determines assembly order, not network arrival time |
| Incomplete stitch detection | If any partial is missing, the assembled artefact is flagged INCOMPLETE — not silently assembled with gaps |
| Tamper-evidence | Any alteration to any partial breaks the stitch_hash |
| Independently re-verifiable | Any third party can re-assemble from the original partials and recompute |
| Source diversity preserved | Each partial retains its original issuer_did — the assembled artefact does not mask its sources |
Cross-jurisdiction stitching (P17, P19)
When partials originate from different jurisdictions, each may have been produced under a different normalisation profile. P19 defines the cross-jurisdiction stitching protocol:
| Step | What happens |
|---|---|
| 1 | Each partial carries its normalisation_profile_id |
| 2 | The stitching agent checks all profiles are declared compatible in the registry |
| 3 | If profiles differ, a canonical cross-profile transform is applied before assembly |
| 4 | The stitch_record includes all normalisation_profile_ids used in the assembly |
| 5 | Verifiers can reproduce the cross-profile transform from the declared profile IDs |
This means a single compliance artefact stitched from EU, US, and Singapore source evidence can carry a stitch_hash verifiable in all three jurisdictions.
Stitching and the evidence graph
Each assembled artefact is a node in the evidence graph. Each partial is also a node. The stitching relationship is recorded as a derived_from edge from each partial to the assembled artefact.
This means the evidence graph is always fully decomposable: a retriever encountering an assembled artefact can always trace back to its source partials and re-verify each one independently. There is no compression or information loss in assembly.
Use cases
| Domain | What is stitched |
|---|---|
| Enterprise compliance | Partial compliance evidence from multiple departments and jurisdictions |
| Clinical trials | Site-level trial data from independent investigators across multiple locations |
| Construction | Inspection and test records from multiple independent subcontractors |
| Supply chain | Provenance records from each independent stage of the chain |
| Swarm governance | LocalDominanceHash records from multiple agents into a GlobalDominanceState |
| Financial audit | Attestations from independent auditors into a single audited record |
Related to Evidence Stitching
- Evidence Normalisation — normalisation profiles that precede stitching
- Evidence Weight — how assembled artefacts are weighted
- Divergence — what happens when stitching reveals contradictory partials
- Swarm — swarm-level evidence aggregation using stitching primitives
- Regulatory Governance — cross-jurisdiction compliance use
- Patents — P18, P19
Patents
- P18 — Evidence Stitching Protocol. Filed November 2025, UK IPO.
- P19 — Cross-Jurisdiction Evidence Stitching and Normalisation Profile Compatibility. Filed November 2025, UK IPO.