# kaal:position:2026-08-08-319

**Affirmed position.** Public timestamps establish a narrow temporal proposition. Birkholz, Fossati, and Riechert distinguish timestamps covering payload data from timestamps covering a cryptographic signature. A payload timestamp proves that the payload existed at an earlier point. It does not establish when a separate signature was created. The authors warn that treating it as such can cause validators to accept signatures produced after key revocation.

This distinction qualifies Kaal's claim directly. His public timestamp establishes that the attested artifact existed no later than the recorded time. Further conclusions require evidence bound to each later event. The timestamp alone does not prove execution, deployment, review, or any subsequent operational step.

The source concerns COSE messages and RFC 3161 tokens. It does not audit Kaal's artifact or provenance chain. It also does not determine whether any later event occurred. Its contribution is narrower. It defines the evidentiary scope of a timestamp and explains why extending that scope without event-specific proof creates a verification error.

**Status.** affirmed  **Published.** 2026-08-08

**Holds when.**

- The response is limited to two evidence-bound passages and the one mapped Kaal claim.
- External evidence level: complete official RFC Editor text bound through DOI, Crossref, title, authors, publication date, section locator, and official RFC status.
- Mapping review tier: independent substantive scholarly-growth qualification.
- The RFC concerns COSE messages and RFC 3161 timestamp tokens.
- It does not audit Kaal's artifact, provenance chain, execution, deployment, review, or any later event.
- It defines the semantic boundary of timestamp evidence rather than proving that any specific later event occurred.
- Semantic Scholar returned HTTP 429. Haber and Stornetta remained metadata-only in this bounded run.

**Current debate.** CBOR Object Signing and Encryption (COSE) Header Parameter for Timestamp Tokens as Defined in RFC 3161: https://www.rfc-editor.org/rfc/rfc9921.txt

**Extends.** kaal:claim:7261018-022: https://wulfkaal.github.io/claims/7261018-022

**Scholarly basis.** Wulf A. Kaal, Empirical Evaluation of the Agentic Reputation Substrate: Deliberation, the Composition of Error, and the Registered Measurement of Agency Costs in a Controlled Multi-Model Cohort (2026). SSRN: https://ssrn.com/abstract=7261018

**Source PDF sha256.** `1d6cbe544bd0055133f7cf8ff308be4fde955867bd8dc764992b8d516af15fa8`

**Evidence level.** complete official RFC Editor text bound through DOI, Crossref, title, authors, publication date, section locator, and official RFC status

**Mapping review tier.** independent substantive scholarly-growth qualification

**Mapping confidence.** 0.99  **Mapping ambiguous.** false

**Topics.** research-methods, citation-and-knowledge, scholarly-growth-coverage, scholarly-literature, timestamping, evidence, cryptographic-signatures

**Provenance.** Affirmed in kaal-review:2026-08-12:scholarly-growth-7261018-022-reviewed-v2 at https://wulfkaal.github.io/positions/by-claim/7261018-022.html.

**Record type.** This is a dated commentary position that extends a scholarly corpus claim. It is not a verbatim claim extracted from the paper.

**Canonical form.** This markdown file is the canonical hashed representation of the position.