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Tyche Institute

News · 17 August 2026

A registered media type for action evidence

On 17 August 2026 IANA entered application/vnd.aep+zip in the media types registry, with Tyche Institute as change controller. The request was filed on 16 July 2026 as ticket #1456142 and reviewed by the IESG-designated media-type expert.

The type names an Action Evidence Package: a signed, append-only ZIP container carrying a canonical record of what an automated system did (RFC 8785), its SHA-256 hash, a detached signature and an RFC 3161 timestamp token. The profile forbids nested directories, fixes the member names, caps the uncompressed size at 10 MB and requires duplicate entries to be rejected — the constraints that make a ZIP safe to parse from an untrusted source.

A media type is a small thing to celebrate, so it is worth being exact about what changed. A Record in a RATS Conceptual Message Wrapper (RFC 9999, July 2026) is keyed by media type. Until this registration, an Action Evidence Package could ride inside one only under a value that two parties had agreed privately between themselves — which means the format was interoperable exactly as far as the next bilateral conversation. It now has a name that any party can resolve from a public registry, without asking us.

Three things this is not. It is a registration in the vendor tree: no RFC, no IETF consensus, and not an IETF standard. A registration records a name and who controls it — it is not a review or an endorsement of the format's security properties. And the registered name is shorter than the one we filed: the designated expert narrowed application/vnd.eatf.aep+zip to application/vnd.aep+zip. Only the shorter name exists, and material published before 18 August 2026 that carries the longer one is out of date.

The type is used by the open EATF verifier tooling and by the composition described in the individual Internet-Draft draft-sokolov-rats-aep-composition (revision -04, 13 August 2026), which is not a working-group document and has not been adopted by the RATS WG.

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