LangEdge, Inc. This specification extends JSON Web Signature (JWS, [RFC7515]) and defines LTV-JWS, a lightweight long-term signature format for Long- Term Validation (LTV). LTV-JWS adds signature extension elements, timestamps [RFC3161], validation information (certificates [RFC5280], CRLs [RFC5280], and OCSP responses [RFC6960]), and archive structures as minimal extensions, thereby enabling the validity of signatures to be verified over extended periods of time. In addition, archive timestamps enable continued validation even after the obsolescence or compromise of cryptographic algorithms. LTV-JWS preserves the simple structure and concept of JWS while progressively adding timestamps and validation information. It also enables more general-purpose signing use cases through indirect signatures using external references (refs).