XAdES

Description

While XML-DSig is a general framework for digitally signing documents, XAdES specifies precise profiles of XML-DSig making it compliant with the European eIDAS regulation (Regulation on electronic identification and trust services for electronic transactions in the internal market). The eIDAS regulation enhances and repeals the Electronic Signatures Directive 1999/93/EC. EIDAS is legally binding in all EU member states since July 2014. An electronic signature that has been created in compliance with eIDAS has the same legal value as a handwritten signature.

An electronic signature, technically implemented based on XAdES has the status of an advanced electronic signature. This means that

• it is uniquely linked to the signatory;
• it is capable of identifying the signatory;
• only the signatory has control of the data used for the signature creation;
• it can be identified if data attached to the signature has been changed after signing.

A resulting property of XAdES is that electronically signed documents can remain valid for long periods, even if underlying cryptographic algorithms are broken.

However, courts are not obliged to accept XAdES-based electronic signatures as evidence in their proceedings; at least in EU, this is compulsory only for "qualified" signatures. A "qualified electronic signature" needs to be doted with a digital certificate, encrypted by a security signature creation device, and the identity of the owner of this signing-certificate must have been verified according to the "high" assurance level of the eIDAS regulation.