One Signature Certificates#

Stefan Santesson, Russ Housley (LAMPS WG)

• Why: A genuinely novel certificate profile: certificates that exist to validate exactly one signature, with the key destroyed immediately after — eliminating expiry and revocation complexity for long-lived document validation.
• What: Per the slides: key pair generated, certificate issued, document signed, private key destroyed. The certificate never expires (notAfter = 99991231235959Z), never revokes (id-ce-noRevAvail), and is bound to the single signed document via a new signedDocumentBinding extension (dataTbsHash + hash algorithm + binding type), with binding-type variants for CAdES/XAdES/JWS/COSE that hash only the payload where the signing process covers certificate data.
• How: Binding the certificate to the document hash makes the certificate meaningless for any other use; long-term validation reduces to verifying the signature against a certificate that can never be revoked or expire.
• Where applicable: Long-lived signed documents (contracts, archival records) rather than TLS/workload identity. The LAMPS adoption call ended 2026-03-13 and the draft is being republished as a LAMPS WG document — a small but real shift in how PKI can work.