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Signed Context Manifest

Attestation artifact — instantiates Definition-Time Context Binding

A manifest of a behavior's bound context sealed with a cryptographic signature, so any receiver can verify the context is authentic and unaltered before trusting the behavior to run.

A signed context manifest takes a record of the context a behavior was bound to — its versions, identities, configuration, provenance — and seals it with a cryptographic signature from the party that produced it. The manifest answers "what context governs this?"; the signature answers "can I trust that answer, and that no one has changed it since?" Its defining move is verifiable integrity and provenance: a receiver in another process, organization, or time can check the signature and know both who attested the context and that it has not been tampered with, before deciding the bundle is safe to execute. It does not itself enumerate or serialize the context — it signs a manifest another mechanism produced — and the accumulating chain of verified signatures becomes a durable audit surface.

Example

A continuous-integration build produces a release and emits a manifest listing the exact source commit, base-image digest, compiler version, and dependency-lockfile hash that defined the build, signed with the build system's key. Weeks later, a deployment gate at a different company verifies that signature before promoting the artifact to production.

If the manifest was altered in flight — a dependency swapped, the base image changed — the signature no longer checks and the promotion is blocked. The list of what was bound comes from the manifest; what this mechanism adds is the seal that lets a party who shares no memory or infrastructure with the builder still trust it. Named provenance frameworks such as SLSA, in-toto, and Sigstore formalize exactly this pattern in the software supply chain.[1]

How it works

  • Take a manifest as input. The enumerated context — versions, provenance, identities — is produced elsewhere; this mechanism operates on that record rather than building it.
  • Seal it. Compute a signature over the manifest with the producer's key, binding the content to an attestable identity and making any later change detectable.
  • Verify before trust. A receiver checks the signature and the signer's authority as a gate: valid means the context is authentic and unaltered; invalid or missing means reject or quarantine.
  • Accumulate an audit trail. Signed manifests are retained as evidence of which context governed which execution, inspectable long after the run.

Tuning parameters

  • What the signature covers — the whole manifest or selected fields; covering more detects more tampering but makes benign edits (re-ordering, annotation) break verification.
  • Signer identity and key management — a single build key, per-stage keys, or a transparency log; stronger identity and rotation raise trust and operational cost.
  • Verification posture — hard-fail (block on any invalid signature) versus warn; hard-fail is safer but brittle to key rotation and clock skew.
  • Attestation freshness — whether a signature is valid indefinitely or must be re-attested; expiry limits replay of an old, since-revoked context.
  • Retention of signed manifests — how long the audit trail is kept, trading storage and exposure against traceability.

When it helps, and when it misleads

Its strength is letting context be trusted across a boundary where the parties share neither memory nor management — the archetype's "a receiver can determine whether a bundle is safe to execute before activation," extended to authenticity. It converts "I think this is the context" into "I can verify this is the context," and leaves a tamper-evident record behind.

A signature proves integrity and origin, not correctness — a faithfully signed manifest of the wrong context is still wrong, and over-trust in the green checkmark is the subtle failure. The classic misuse is the backdated attestation: assembling and signing a manifest after a run to manufacture a provenance story the execution never actually followed — the mechanism run backwards to produce compliance theater. Key compromise voids everything downstream, and a signature says nothing about whether the signed context was minimal or leaked secrets. The discipline is to sign the context that actually governed, at the time it governed; verify signer authority, not just signature validity; and treat the manifest's contents as a separate question from its seal.

How it implements the components

  • context_integrity_signature — the cryptographic seal over the manifest is the mechanism's core: tamper-evidence plus attributable origin.
  • observability_and_audit_surface — verified signatures accumulate into a durable, inspectable record of which context governed which execution.

It seals a manifest; it does not create one. Enumerating the bound context and its versions is a Versioned Context Manifest; pinning reproducible configuration values is a Versioned Configuration Snapshot; moving the sealed bundle across a boundary is a Serialized Job Envelope; and carrying scoped, revocable authority is a Revocable Authority Token.

Notes

A valid signature certifies that the manifest is authentic and unchanged — not that the context it records is correct, minimal, or still current. Integrity and validity are separate gates; this mechanism supplies only the first, which is why it pairs with, rather than replaces, the manifest that decides what to bind.

References

[1] Supply-chain frameworks such as in-toto and SLSA formalize signed provenance: each step attests, with a verifiable signature, to the inputs and environment it used, and downstream consumers verify the chain before trusting an artifact. The pattern generalizes beyond software — the signature establishes authenticity and non-tampering, never that the attested context was itself correct. ↩