Sophia Antipolis, 21 February 2024

ETSI’s first LTA Signature Augmentation and Validation Plugtests™ has seen international participants exchange over 35 000 digital signature validation reports.

Held from 23 October - 22 December 2023, the remote interoperability event was organized by the ETSI Centre for Testing and Interoperability (CTI), on behalf of ETSI’s Technical Committee for Electronic Signatures and Trust Infrastructures (TC ESI). This Plugtests™ event was facilitated with the support and co-funding of the European Commission (EC) and the European Free Trade Association (EFTA).

Conducted using a dedicated web portal, sessions over the month-long Plugtests™ attracted the involvement of 190 participants from 121 organizations across 38 countries.

The event’s aim was to test interoperability of digital signatures conforming to LTA (Long-Term Archive) level, as well as validation capacities of LTA-level signatures of the participants. This assisted participants in detecting possible issues which may lead to different augmentation and/or validation results.

Testing covered validation of the five main digital signature formats (XAdES, PAdES, CAdES, ASiC, and JAdES). It also addressed the Incorporation of Evidence Record Syntax (ERS) mechanisms in CAdES (as described in ETSI Technical Specifications (TS 119 122-3) and XAdES (TS 119 132-3).

Plugtests™ participants were able to test their own digital signature validation tools, and to cross-validate ETSI Electronic Signatures/Seals relying on EU Member States' Trusted Lists (based on TS 119 612 and TS 119 615) and according to the following standards:

  • EN 319 102-1 (Procedures for Creation and Validation of AdES Digital Signatures; Part 1: Creation and Validation) updated in 2021-11;
  • TS 119 102-2 (Procedures for Creation and Validation of AdES Digital Signatures; Part 2: Signature Validation Report) updated in 2023-06;
  • TS 119 172-4 (Signature Validation Policy for European Qualified Electronic Signatures/Seals Using Trusted Lists) published in 2021-05;
  • TS 119 312 (Cryptographic Suites) updated in 2023-08.

"It is an increasingly routine requirement in financial, legal and other sectors to ensure the authenticity and validity of digitally signed documents for an extended time period – maybe decades” comments Nick Pope, Chair of ETSI’s Technical Committee on Electronic Signatures and Trust Infrastructures. “Whatever technology and societal developments are in store, it’s essential that we have robust standards in place to confirm validity of a document’s signature long into the future."

"This event is one in a series of Plugtests™ which are proving invaluable to those implementing ETSI’s standards in support of European regulations for electronic signatures and seals. It is also enabling ETSI to ensure the efficacy of its own standards for digital signatures."

35 225 validation reports were exchanged during the month-long Plugtests™ event, verifying more than 3 200 Signatures and LTA Augmentations.

About ETSI

ETSI provides members with an open and inclusive environment to support the development, ratification and testing of globally applicable standards for ICT systems and services across all sectors of industry and society.  We are a non-profit body, with more than 900 member organizations worldwide, drawn from 64 countries and five continents. The members comprise a diversified pool of large and small private companies, research entities, academia, government, and public organizations. ETSI is officially recognized by the EU as a European Standards Organization (ESO). For more information, please visit us at