Electronic Signatures and Infrastructures (ESI); CAdES Baseline Profile

Note

ETSI technical specification defining a baseline profile for CAdES signatures, with four conformance levels to maintain long-term validity (version 2.2.1).

Summary

Purpose

Technical specification ETSI TS 103 173 (version 2.2.1, April 2013) is a baseline profile of CAdES signatures, that is, a choice of options among those of the signature format based on CMS (Cryptographic Message Syntax) defined by ETSI TS 101 733 ETSI TS 103 173 V2.2.1, Introduction ETSI TS 103 173 V2.2.1, History. Its scope begins as follows:

It targets the cross-border exchange of signed documents and takes particular account of the needs of the Services Directive 2006/123/EC ETSI TS 103 173 V2.2.1, § 1 Scope. It is the former generation: ETSI EN 319 122-1 treats signatures produced according to TS 103 173 as “legacy” CAdES baseline signatures ETSI EN 319 122-1 V1.3.1, § 3.1 Terms ETSI EN 319 122-1 V1.3.1, § 6.4 Legacy CAdES baseline signatures.

Who it applies to

• To Member States, which recognise advanced electronic signatures and seals conforming to this profile where they were created before 23 February 2028 Art. 1(2) Art. 3(2).
• To the signature validation applications targeted by the intermediate standard described below, in the form of a recommendation ETSI TS 119 172-4 V1.1.1, § 4.3 Requirements on signature validation and applicability rules checking practices.

Key points

• Four conformance levels, each building on the previous one: B (basic level), T (token proving the existence of the signature at a given time), LT (validation data included in the signature) and LTA (archive time-stamps for validation long afterwards) ETSI TS 103 173 V2.2.1, § 4 Conformance Levels. At the LTA level, the specification requires one or more archive-time-stamp-v3 attributes, defined by TS 101 733 version 2.2.1 ETSI TS 103 173 V2.2.1, § 9 Requirements for LTA-Level Conformance.
• One clause per level: clauses 6 (B), 7 (T), 8 (LT) and 9 (LTA) ETSI TS 103 173 V2.2.1, § 1 Scope ETSI TS 103 173 V2.2.1, § 4 Conformance Levels.
• Preservation: the specification states that long-term archiving generally requires the LTA level, a lower level being sufficient if combined with other protection techniques ETSI TS 103 173 V2.2.1, § 4 Conformance Levels.

What the acts apply, and how

• Implementing Regulation 2026/248: Member States recognise advanced electronic signatures and seals whose format complies with the specifications of Annex II, where they were created before 23 February 2028 Art. 1(2) Art. 3(2). Annex II lists TS 103 173 v.2.2.1 there, except its paragraph 9 and at conformance level B, T or LT Annex II. Paragraph 9 is that of the LTA level ETSI TS 103 173 V2.2.1, § 9 Requirements for LTA-Level Conformance. Article 6 defers only paragraph 1 of these two articles, applicable from 23 February 2027 Art. 6. Annex I, to which these paragraphs 1 refer, names ETSI EN 319 122-1 version 1.3.1 Annex I ETSI EN 319 122-1 V1.3.1. The regulation repeals Implementing Decision 2015/1506 Art. 5.
• Through ETSI TS 119 172-4 version 1.1.1: Implementing Regulations 2025/1942 (qualified validation), 2025/1945 (validation of signatures and seals) and 2025/1946 (qualified preservation) make this specification applicable with adaptations Annex List of reference standards and specifications for the validation of qualified electronic signatures and of qualified electronic seals List of reference standards and specifications for the validation of advanced electronic signatures based on qualified certificates and of advanced electronic seals based on qualified certificates List of reference standards and specifications referred to in Article 2. Its requirement REQ-4.3-01 recommends (should) that the validation application support formats conforming to TS 103 173, cited without a version, as it does the other baseline profiles ETSI TS 119 172-4 V1.1.1, § 4.3 Requirements on signature validation and applicability rules checking practices ETSI TS 119 172-4 V1.1.1, § 2.1 Normative references. None of these three regulations modifies this requirement; they adapt other requirements of the same clause or other clauses. It therefore remains a recommendation in the standard made applicable. Regulation 910/2014 attaches presumptions to these standards: the validation of qualified electronic signatures, that of advanced electronic signatures based on a qualified certificate, the qualified validation service and the qualified preservation service are presumed to meet the requirements laid down in paragraph 1 of the article concerned (in its first subparagraph for the validation of qualified signatures) where they comply with these standards, specifications and procedures; these rules also apply to seals Art. 32(1) Art. 32a(3) Art. 33(2) Art. 34(1a) Art. 40 Art. 40a Art. 1 Art. 1 Art. 1.

Important clauses

• ETSI TS 103 173 V2.2.1, § 1 Scope: scope.
• ETSI TS 103 173 V2.2.1, § 4 Conformance Levels: conformance levels.
• ETSI TS 103 173 V2.2.1, § 6 Requirements for B-Level Conformance: level B.
• ETSI TS 103 173 V2.2.1, § 9 Requirements for LTA-Level Conformance: level LTA (excluded by Annex II to Implementing Regulation 2026/248).

Links

• Standard that succeeds it: ETSI EN 319 122-1 ETSI EN 319 122-1 V1.3.1.
• Related former profiles: XAdES ETSI TS 103 171 V2.1.1, PAdES ETSI TS 103 172 V2.2.2, ASiC containers ETSI TS 103 174 V2.2.1.
• Learning path: step 4, trust services.

ETSI standard: the site reproduces only short extracts; the full text is available from ETSI ETSI TS 103 173 V2.2.1. Written by Asphalia.