XADES

XML Advanced Electronic Signatures. The ETSI extension to XML Signature that makes signatures compatible with the eIDAS regulation — timestamps, signed attributes, long-term archival.

Definition

XAdES is a family of ETSI (European Telecommunications Standards Institute) standards specifying the creation and verification of XML electronic signatures compliant with European Regulation 910/2014 (eIDAS). XAdES defines a series of profiles, from simplest to most complete:

• XAdES-B-B (Basic, B-Level): XML Signature + qualifying properties (signer certificate, signed references, signed data).
• XAdES-B-T (Timestamp): adds a qualified timestamp (RFC 3161) over the signature.
• XAdES-B-LT (Long Term): adds the certificates and CRL/OCSP required for offline verification.
• XAdES-B-LTA (Long Term Archive): adds archive timestamps to preserve validity over the long run (periodic renewal before algorithm or certificate expiry).

The signed attributes (SignedProperties) cover SigningTime, SigningCertificate, SignaturePolicyIdentifier, SignedDataObjectProperties, etc. Unsigned attributes (UnsignedProperties) host timestamps, validation references and counter-signatures.

Origin

XAdES was published by ETSI TC ESI (Electronic Signatures and Infrastructures) in 2002 under reference TS 101 903. It was reworked in 2016 under the dual framework EN 319 132-1 (formats) and EN 319 132-2 (verification), to align with the eIDAS regulation effective in July 2016. CAdES (CMS Advanced Electronic Signatures) is the binary CMS counterpart, PAdES covers PDF, JAdES covers JSON Web Signatures.

Example in context

A UBL invoice conformant to FacturaE (Spain) or FatturaPA (Italy) is signed XAdES-B-LT. The signer is typically the supplier, but in the Italian model the Sistema di Interscambio (SDI) applies the qualified signature. The receiver verifies the certification chain against the European TSL (Trusted List), the timestamps against a recognised authority and the signature itself. Any failure invalidates the document for tax purposes.

Related terms

• W3C XML Schema — XAdES builds on XML Signature, defined by the W3C.
• WS-Security — also uses XML Signature.
• Non-repudiation — the property provided by XAdES.
• EN 16931 — the invoice standard that references XAdES in its ecosystem.