Security Guidelines on the Appropriate Use of Qualified Electronic Signatures Guidance for Users
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Security guidelines on the appropriate use of qualified electronic signatures Guidance for users VERSION 2.0 FINAL DECEMBER 2016 www.enisa.europa.eu European Union Agency For Network And Information Security Security guidelines on the appropriate use of qualified electronic signatures | Version 2.0 | Final | DECEMBER 2016 About ENISA The European Union Agency for Network and Information Security (ENISA) is a centre of network and information security expertise for the EU, its member states, the private sector and Europe’s citizens. ENISA works with these groups to develop advice and recommendations on good practice in information security. It assists EU member states in implementing relevant EU legislation and works to improve the resilience of Europe’s critical information infrastructure and networks. ENISA seeks to enhance existing expertise in EU member states by supporting the development of cross-border communities committed to improving network and information security throughout the EU. More information about ENISA and its work can be found at www.enisa.europa.eu. Contact For contacting the authors please use [email protected] For media enquires about this paper, please use [email protected]. Legal notice Notice must be taken that this publication represents the views and interpretations of the authors and editors, unless stated otherwise. This publication should not be construed to be a legal action of ENISA or the ENISA bodies unless adopted pursuant to the Regulation (EU) No 526/2013. This publication does not necessarily represent state-of the-art and ENISA may update it from time to time. Third-party sources are quoted as appropriate. ENISA is not responsible for the content of the external sources including external websites referenced in this publication. This publication is intended for information purposes only. It must be accessible free of charge. Neither ENISA nor any person acting on its behalf is responsible for the use that might be made of the information contained in this publication. Copyright Notice © European Union Agency for Network and Information Security (ENISA), 2016 Reproduction is authorised provided the source is acknowledged. ISBN 978-92-9204-212-7, DOI 10.2824/399794 02 Security guidelines on the appropriate use of qualified electronic signatures | Version 2.0 | Final | DECEMBER 2016 Contents Executive Summary 6 1. Introduction 7 1.1 General context/the eIDAS Regulation on eID and trust services 7 1.2 Opportunities brought by eIDAS Regulation 7 1.3 Specific role of the qualified trust services 8 1.4 Initiation and supervision of qualified trust services 8 1.5 A focus on qualified electronic signatures 10 1.6 Scope of the present document and relationship with other recommendations 11 2. Qualified electronic signature – what is it? 13 2.1 Legal definition of (qualified) electronic signatures 13 2.2 Public Key Cryptography as technical foundations for (Q)ES 14 2.3 Certification services as trust foundation for (Q)ES 16 2.4 The electronic signature process 17 2.5 Qualified electronic signatures 18 3. Qualified electronic signature – what key properties does it provide? 20 3.1 Legal properties 20 3.2 Security properties 20 3.3 Functional Properties 20 3.4 Other Properties 21 4. Qualified electronic signature – what properties can it not provide? 22 4.1 Legal properties not provided by QES 22 4.2 Security properties not provided by QES 22 4.3 Functional properties not offered by QES 22 4.4 Other properties not offered by QES 22 5. Qualified electronic signature – what are the potential use cases? 24 5.1 Overview and context of the given examples 24 5.2 Signing a document/message to confirm origin 24 5.3 Signing of a document/declaration 25 03 Security guidelines on the appropriate use of qualified electronic signatures | Version 2.0 | Final | DECEMBER 2016 5.4 Signing a (commercial) proposal 25 5.5 Signing of an official document/attestation 26 5.6 Signing of a legal consent / an eMandate / … 26 5.7 Signing of a contract 26 6. Qualified electronic signature – what are the usage best practices? 27 6.1 Security Guidelines & Levels 27 6.2 BASIC 27 6.3 RECOMMENDED 28 6.4 ENHANCED 29 7. Qualified electronic signatures – example of tools & practical usage aspects 32 7.1 Implementing qualified electronic signatures (user perspective) 32 7.2 Relevant standards regarding qualified electronic signatures (expert perspective) 34 Annex A - Glossary 36 eIDAS – What is it? 36 Electronic seal 36 Hash value (of a file) 36 Intellectual property 36 Trusted list 36 QTSP/QTS requirements and obligations 37 CEF eSignature building blocks 38 Trust services defined by the eIDAS Regulation 38 Qualified trust services defined by the eIDAS Regulation 39 Other terms 40 Acronyms 42 Annex B - Possible mapping basic/recommended/enhanced vs business criticality and/or data protection 44 B.1 Understanding an organization’s environment and corresponding criticality-levels 44 Annex C - References and bibliography 46 References 46 Bibliography 46 Relevant implementing acts 46 04 Security guidelines on the appropriate use of qualified electronic signatures | Version 2.0 | Final | DECEMBER 2016 Annex D - Frequently asked questions 47 What about the (international) recognition of electronic signatures (within Europe)? 47 What about the (international) recognition of electronic signatures (outside Europe)? 47 eIDAS Regulation – Questions and answers on rules applicable to trust services as of 1 July 2016 48 How can I find a qualified trust service provider issuing qualified certificates for electronic signatures? 48 How can I find a qualified trust service provider providing qualified preservation services for qualified electronic signatures? 48 How can I find a qualified trust service provider providing qualified validation services for qualified electronic signatures? 49 05 Security guidelines on the appropriate use of qualified electronic signatures | Version 2.0 | Final | DECEMBER 2016 Executive Summary On July 1st 2016, Regulation (EU) 910/2014 (hereafter called the eIDAS Regulation), which lays down the rules on electronic identification and trust services for electronic transactions in the internal market came into force covering across Europe in all 28 Member States. It defines trust services for supporting electronic signatures, electronic seals, electronic time stamps, electronic registered delivery services and website authentication. The eIDAS Regulation represented a big step forward in building a digital single market as it provides one common legal framework for all parties relying or providing on those kind of services. Indeed, various sectors of the economy (e.g. finance, banking, transport, insurance, health, sharing economy, trading, etc.) where obligations exist for security, reliable identification, strong authentication, legal certainty of evidences, will clearly be positively affected by the eIDAS Regulation. This latter will indeed allow citizens, businesses and public administrations to meet such obligations for any (cross-border) electronic transaction as they will now be able to use the recognised eID means and (qualified) trust services. In particular, a qualified electronic signature shall have the equivalent legal effect of a handwritten signature and, when based on a qualified certificate issued in one Member State, shall be recognised as a qualified electronic signature in all other Member States. This document addresses qualified electronic signatures and is one out of a series of five documents which target to assist parties aiming to use qualified electronic signatures, seals, time stamps, eDelivery or website authentication certificates to understand the subject correctly as-well-as the potential benefits, amongst others, by giving examples of possible application. This series of documents also targets to give those parties some advice on how to correctly use the related (qualified) trust services. After explaining what a qualified eSignature is and what properties/function it does and does not provide, concrete examples of use are given for inspiration to the readers. Next to them, and as even the most secure / trusted service becomes insecure and unreliable if not being integrated or used correctly, some key recommendations are given for correct integration and use, pertaining: Both the signatory and the relying party should look for the EU trust mark for qualified trust services when selecting providers. The relying party shall follow the applicable Certification Authority’s terms and conditions and/or other contractual documentation. The first level of augmentation consists in time-stamping the signature In a signature with Long Term Validation Data, the set of validation material or references to it should be sufficient to ascertain the validation status of all end-entity certificates contained in the signature. Before algorithms, keys, and other cryptographic data used at the time a signature was built become weak and the cryptographic functions become vulnerable, or the certificates supporting previous time stamp tokens expire or are revoked, the signed data, the signature as well as any additional information should be protected by applying time stamp tokens. QES services should be further supported by ancillary qualified trust services. The relying party should verify that the provider is duly qualified is to check its presence in the trusted list of the Member State where it operates. 06 Security guidelines on the appropriate use of qualified electronic signatures