RFC 9921 - CBOR Object Signing and Encryption (COSE) Header Parameter for Timestamp Tokens as Defined in RFC 3161

• Status: Proposed Standard
• Published: February 2026
• Stream: IETF
• Errata: RFC Editor Errata

Abstract

This document defines two COSE header parameters for incorporating RFC 3161 timestamp tokens into COSE_Sign and COSE_Sign1 structures, enabling established timestamping infrastructure in COSE-based protocols.

Contents

• 1. Introduction
• 2. Modes of Use
• 3. Timestamp Tokens per RFC 3161: COSE Header Parameters
• 4. Timestamp Processing
• 5. Security Considerations
• 6. IANA Considerations
• 7. Normative References
• Appendix A. Examples
• Acknowledgments
• Contributors
• Authors' Addresses

Related Resources

• Official Text: RFC 9921
• Official Page: RFC 9921 DataTracker
• Errata: RFC Editor Errata