CBOR Object Signing and Encryption Header Parameter for Timestamp Tokens as Defined in RFC 3161
RFC 9921, “CBOR Object Signing and Encryption Header Parameter for Timestamp Tokens as Defined in RFC 3161”, is a Proposed Standard document published in February 2026 by H. Birkholz, T. Fossati, M. Riechert. The canonical text is published by the RFC Editor.
Abstract
This document defines two CBOR Object Signing and Encryption (COSE) header parameters for incorporating timestamping based on RFC 3161 into COSE message structures (COSE_Sign and COSE_Sign1). This enables the use of established timestamping infrastructure per RFC 3161 in COSE-based protocols.
What “Proposed Standard” means
An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.
The canonical text of RFC 9921 is hosted at rfc-editor.org. Available in HTML,TXT,PDF,XML.
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