JAdES

JAdES is the ETSI standard for embedding advanced electronic signatures in JSON data, built on JWS - used in APIs and digital wallets.

JAdES (JSON Advanced Electronic Signatures) is the ETSI standard, formally ETSI TS 119 182-1 (V1.2.1, 2024-07), that defines how an electronic signature or electronic seal is embedded in or associated with data expressed as JSON. Unlike XAdES, CAdES and PAdES, which are published as ETSI European Norms (EN), JAdES remains a Technical Specification (TS), reflecting its more recent standardisation. It builds on the IETF's JSON Web Signature (JWS, RFC 7515), adding the signed and unsigned attributes - signing time, certificate references, commitment type - that AdES signature formats require, so a JWS-based signature can qualify as an advanced or qualified electronic signature under eIDAS.

JAdES is the newest of the four AdES formats, alongside PAdES, XAdES and CAdES, and fits naturally where PDF, XML or CMS containers do not: APIs, mobile apps and JSON-native data exchanges such as open banking or wallet protocols. Two serialisations exist: JWS Compact Serialization (a compact string, easy to pass in headers or URLs) and JWS JSON Serialization (readable JSON, supporting multiple signatures over the same payload). For the shared EU timeline on when public sector bodies must accept JAdES alongside PAdES, XAdES and CAdES, see AdES signature formats.