ETSI EN 319 421 V1.2.0 (2023-01)

Electronic Signatures and Infrastructures (ESI); Policy and Security Requirements for Trust Service Providers issuing Time-Stamps

REN/ESI-0019421v1.2.1

General Information

• Status: Not Published
• Technical Committee: ESI - Electronic Signatures and Infrastructures
• Current Stage: 9 - Start of OAP
• Due Date: 31-Jan-2023
• Completion Date: 31-Jan-2023
• Mandate: M/460

Standards Content (Sample)

Draft ETSI EN 319 421 V1.2.0 (2023-01)
EUROPEAN STANDARD
Electronic Signatures and Infrastructures (ESI);
Policy and Security Requirements for
Trust Service Providers issuing Time-Stamps
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2 Draft ETSI EN 319 421 V1.2.0 (2023-01)
Reference
REN/ESI-0019421v1.2.1
Keywords
e-commerce, electronic signature, security,
time-stamping, trust services
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ETSI
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3 Draft ETSI EN 319 421 V1.2.0 (2023-01)
Contents

Intellectual Property Rights ................................................................................................................................ 5

Foreword ............................................................................................................................................................. 5

Modal verbs terminology .................................................................................................................................... 5

Introduction ........................................................................................................................................................ 6

1 Scope ........................................................................................................................................................ 7

2 References ................................................................................................................................................ 7

2.1 Normative references ......................................................................................................................................... 7

2.2 Informative references ........................................................................................................................................ 8

3 Definitions of terms, symbols, abbreviations and notation ...................................................................... 9

3.1 Terms .................................................................................................................................................................. 9

3.2 Symbols .............................................................................................................................................................. 9

3.3 Abbreviations ................................................................................................................................................... 10

3.4 Notation ............................................................................................................................................................ 10

4 General concepts .................................................................................................................................... 10

4.1 General policy requirements concepts .............................................................................................................. 10

4.2 Time-stamping services .................................................................................................................................... 11

4.3 Time-Stamping Authority (TSA) ..................................................................................................................... 11

4.4 Subscriber ......................................................................................................................................................... 11

4.5 Time-stamp policy and TSA practice statement ............................................................................................... 11

5 Introduction to time-stamp policies and general requirements .............................................................. 12

5.1 General requirements ....................................................................................................................................... 12

5.2 Policy name and identification ......................................................................................................................... 12

5.3 User community and applicability .................................................................................................................... 12

5.3.1 Best practices time-stamp policy ................................................................................................................ 12

6 Policies and practices ............................................................................................................................. 12

6.1 Risk assessment ................................................................................................................................................ 12

6.2 Trust Service Practice Statement ...................................................................................................................... 13

6.3 Terms and conditions ....................................................................................................................................... 13

6.4 Information security policy .............................................................................................................................. 13

6.5 TSA obligations ................................................................................................................................................ 13

6.5.1 General ........................................................................................................................................................ 13

6.5.2 TSA obligations towards subscribers .......................................................................................................... 13

6.6 Information for relying parties ......................................................................................................................... 14

7 TSA management and operation ............................................................................................................ 14

7.1 Introduction ...................................................................................................................................................... 14

7.2 Internal organization......................................................................................................................................... 14

7.3 Personnel security............................................................................................................................................. 14

7.4 Asset management ............................................................................................................................................ 15

7.5 Access control .................................................................................................................................................. 15

7.6 Cryptographic controls ..................................................................................................................................... 15

7.6.1 General ........................................................................................................................................................ 15

7.6.2 TSU key generation .................................................................................................................................... 15

7.6.3 TSU private key protection ......................................................................................................................... 16

7.6.4 TSU public key certificate .......................................................................................................................... 16

7.6.5 Rekeying TSU's key ................................................................................................................................... 16

7.6.6 Life cycle management of signing cryptographic hardware ....................................................................... 17

7.6.7 End of TSU key life cycle ........................................................................................................................... 17

7.7 Time-stamping ................................................................................................................................................. 17

7.7.1 Time-stamp issuance................................................................................................................................... 17

7.7.2 Clock synchronization with UTC ............................................................................................................... 18

7.8 Physical and environmental security ................................................................................................................ 19

7.9 Operation security ............................................................................................................................................ 19

ETSI
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4 Draft ETSI EN 319 421 V1.2.0 (2023-01)

7.10 Network security .............................................................................................................................................. 19

7.11 Incident management ....................................................................................................................................... 20

7.12 Collection of evidence ...................................................................................................................................... 20

7.13 Business continuity management ..................................................................................................................... 20

7.14 TSA termination and termination plans ............................................................................................................ 20

7.15 Compliance....................................................................................................................................................... 21

8 Additional requirements for qualified electronic time-stamps as per Regulation (EU) No 910/2014 ... 21

8.1 TSU public key certificate ................................................................................................................................ 21

8.2 TSA issuing non-qualified and qualified electronic time-stamps as per Regulation (EU) No 910/2014 ......... 21

Annex A (informative): Potential liability in the provision of time-stamping services .................... 22

Annex B (informative): Model TSA disclosure statement .................................................................. 23

B.1 Introduction ............................................................................................................................................ 23

B.2 TSA disclosure statement structure ........................................................................................................ 23

Annex C (informative): Coordinated Universal Time (UTC)............................................................. 25

Annex D (informative): Long term verification of time-stamps ......................................................... 26

Annex E (informative): Regulation (EU) No 910/2014 and qualified electronic time-stamp

policy cross-reference .................................................................................... 27

Annex F (informative): Possible implementation architectures - time-stamping service ................ 28

F.1 Managed time-stamping service ............................................................................................................. 28

F.2 Selective alternative quality ................................................................................................................... 28

Annex G (informative): Major changes from ETSI TS 102 023 ......................................................... 30

Annex H (informative): Conformity Assessment Check list ............................................................... 31

Annex I (informative): Change History .............................................................................................. 32

History .............................................................................................................................................................. 33

ETSI
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5 Draft ETSI EN 319 421 V1.2.0 (2023-01)
Intellectual Property Rights
Essential patents

IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The declarations

pertaining to these essential IPRs, if any, are publicly available for ETSI members and non-members, and can be

found in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to

ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the

ETSI Web server (https://ipr.etsi.org/).

Pursuant to the ETSI Directives including the ETSI IPR Policy, no investigation regarding the essentiality of IPRs,

including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not

referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become,

essential to the present document.
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Foreword

This draft European Standard (EN) has been produced by ETSI Technical Committee Electronic Signatures and

Infrastructures (ESI), and is now submitted for the combined Public Enquiry and Vote phase of the ETSI standards EN

Approval Procedure.

The present document is derived from the requirements specified in ETSI TS 102 023 [i.8].

Proposed national transposition dates
Date of latest announcement of this EN (doa): 3 months after ETSI publication
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 6 months after doa

Date of withdrawal of any conflicting National Standard (dow): 6 months after doa

Modal verbs terminology

In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and

"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of

provisions).

"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

ETSI
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6 Draft ETSI EN 319 421 V1.2.0 (2023-01)
Introduction

The present document is aiming to meet the general requirements of the international community to provide trust and

confidence in electronic transactions including, amongst others, applicable requirements from Regulation (EU)

No 910/2014 [i.4].

The Regulation includes requirements for Trust Service Providers (TSP) providing services to the public, including

TSPs issuing time-stamps. Additionally, more specific requirements are identified in the Regulation for a specific class

of TSP called a Qualified TSP, with further specific requirements for those Qualified TSPs which issue qualified

time-stamps. The present document is aimed to meet the requirements of the Regulation for both Qualified and

non-Qualified TSPs issuing Qualified and non-Qualified electronic time-stamps respectively.

In order to verify an electronic signature, it can be necessary to prove that the signature from the signer was applied

when the signer's certificate was valid. This is necessary in two circumstances:

1) during the validity period of the signer's certificate, should the signer's certificate be revoked before the end of

its validity, e.g. because the signer's private key has been compromised;

2) after the end of the validity period of the signer's certificate, since CAs are not mandated to process revocation

status information beyond the end of the validity period of the certificates they have issued.

One method consists to use a time-stamp which allows proving that a datum existed before a particular time. This

technique allows proving that the signature was generated before the date contained in the time-stamp. Policy

requirements to cover that case are the primary aim of the present document.
However, these policy requirements allow addressing other needs.

Time-stamping is gaining an increasing interest by the business sector and is becoming an important component of

digital signatures, this is commonly based upon the Time-Stamp protocol from the IETF RFC 3161 [i.2] which is

profiled in ETSI EN 319 422 [5]. Agreed minimum security and quality requirements are necessary in order to ensure

trustworthy validation of long-term digital signatures.
ETSI
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7 Draft ETSI EN 319 421 V1.2.0 (2023-01)
1 Scope

The present document specifies policy and security requirements relating to the operation and management practices of

TSPs issuing time-stamps.

These policy requirements are applicable to TSPs issuing time-stamps. Such time-stamps can be used in support of

digital signatures or for any application requiring to prove that a datum existed before a particular time.

The present document can be used by independent bodies as the basis for confirming that a TSP can be trusted for

issuing time-stamps.
The present document does not specify protocols used to access the TSUs.

NOTE 1: A time-stamping protocol is defined in IETF RFC 3161 [i.2] including optional update in IETF

RFC 5816 [i.3] and profiled in ETSI EN 319 422 [5].

The present document does not specify how the requirements identified can be assessed by an independent party,

including requirements for information to be made available to such independent assessors, or requirements on such

assessors.

NOTE 2: See ETSI EN 319 403-1 [i.9] for guidance on assessment of TSP's processes and services.

NOTE 3: The present document references ETSI EN 319 401 [4] for general policy requirements common to all

classes of TSP's services.
2 References
2.1 Normative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

Referenced documents which are not found to be publicly available in the expected location might be found at

https://docbox.etsi.org/Reference.

NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee

their long term validity.

The following referenced documents are necessary for the application of the present document.

[1] Recommendation ITU-R TF.460-6 (2002): "Standard-frequency and time-signal emissions".

[2] ISO/IEC 19790:2012: "Information technology -- Security techniques -- Security requirements for

cryptographic modules".

[3] ISO/IEC 15408 (parts 1 to 3): "Information security, cybersecurity and privacy protection --

Evaluation criteria for IT security ".

[4] ETSI EN 319 401: "Electronic Signatures and Infrastructures (ESI); General Policy Requirements

for Trust Service Providers".

[5] ETSI EN 319 422: "Electronic Signatures and Infrastructures (ESI); Time-stamping protocol and

time-stamp token profiles".
[6] FIPS PUB 140-2 (2002): "Security Requirements for Cryptographic Modules".
[7] FIPS PUB 140-3 (2019): "Security Requirements for Cryptographic Modules".
ETSI
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8 Draft ETSI EN 319 421 V1.2.0 (2023-01)
2.2 Informative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee

their long term validity.

The following referenced documents are not necessary for the application of the present document but they assist the

user with regard to a particular subject area.

[i.1] ETSI EN 319 122-1: "Electronic Signatures and Infrastructures (ESI); CAdES digital signatures;

Part 1: Building blocks and CAdES baseline signatures".

[i.2] IETF RFC 3161 (2001): "Internet X.509 Public Key Infrastructure: Time-Stamp Protocol (TSP)".

[i.3] IETF RFC 5816: "ESSCertIDV2 update to RFC 3161".

[i.4] Regulation (EU) No 910/2014 of the European Parliament and of the Council on electronic

identification and trust services for electronic transactions in the internal market and repealing

Directive 1999/93/EC.

[i.5] Council Directive 93/13/EEC of 5 April 1993 on unfair terms in consumer contracts.

[i.6] BIPM Circular T.
NOTE: Available from the BIPM website https://www.bipm.org/.

[i.7] ETSI TS 119 312: "Electronic Signatures and Infrastructures (ESI); Cryptographic Suites".

[i.8] ETSI TS 102 023: "Electronic Signatures and Infrastructures (ESI); Policy requirements for time-

stamping authorities".

[i.9] ETSI EN 319 403-1: "Electronic Signatures and Infrastructures (ESI); Trust Service Provider

Conformity Assessment; Part 1: Requirements for conformity assessment bodies assessing Trust

Service Providers".

[i.10] ETSI EN 319 411-1: "Electronic Signatures and Infrastructures (ESI); Policy and security

requirements for Trust Service Providers issuing certificates; Part 1: General requirements".

[i.11] ETSI EN 319 411-2: "Electronic Signatures and Infrastructures (ESI); Policy and security

requirements for Trust Service Providers issuing certificates; Part 2: Requirements for trust service

providers issuing EU qualified certificates".

[i.12] EN 419231: "Protection profile for trustworthy systems supporting time stamping", (produced by

CEN).

[i.13] TS 419221-2: "Protection profiles for TSP Cryptographic modules - Part 2: Cryptographic module

for CSP signing operations with backup", (produced by CEN).

[i.14] TS 419221-3: "Protection profiles for TSP Cryptographic modules - Part 3: Cryptographic module

for CSP key generation services", (produced by CEN).

[i.15] TS 419221-4: "Protection profiles for TSP Cryptographic modules - Part 4: Cryptographic module

for CSP signing operations without backup", (produced by CEN).

[i.16] EN 419221-5: "Protection profiles for TSP Cryptographic modules - Part 5: Cryptographic module

for trust services", (produced by CEN).

[i.17] ETSI TS 119 612: "Electronic Signatures and Infrastructures (ESI); Trusted Lists".

ETSI
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9 Draft ETSI EN 319 421 V1.2.0 (2023-01)
3 Definitions of terms, symbols, abbreviations and
notation
3.1 Terms

For the purposes of the present document, the terms given ETSI EN 319 401 [4] and the following apply:

NOTE: Where a definition is copied from a referenced document this is indicated by inclusion of the reference

identifier number at the end of the definition.

Coordinated Universal Time (UTC): time scale based on the second as defined in Recommendation

ITU-R TF.460-6 [1]

NOTE: For most practical purposes UTC is equivalent to mean solar time at the prime meridian (0°). More

specifically, UTC is a compromise between the highly stable atomic time (Temps Atomique International

- TAI) and solar time derived from the irregular Earth rotation (related to the Greenwich Mean Sidereal

Time (GMST) by a conventional relationship) (see annex C for more details).
relying party: recipient of a time-stamp who relies on that time-stamp

subscriber: legal or natural person to whom a time-stamp is issued and who is bound to any subscriber obligations

time-stamp: data in electronic form which binds other electronic data to a particular time establishing evidence that

these data existed at that time

time-stamp policy: named set of rules that indicates the applicability of a time-stamp to a particular community and/or

class of application with common security requirements

NOTE: This is a specific type of trust service policy as defined in ETSI EN 319 401 [4].

Time-Stamping Authority (TSA): TSP providing time-stamping services using one or more time-stamping units

time-stamping service: trust service for issuing time-stamps

Time-Stamping Unit (TSU): set of hardware and software which is managed as a unit and has a single time-stamp

signing key active at a time

trust service: electronic service that enhances trust and confidence in electronic transactions

Trust Service Provider (TSP): entity which provides one or more trust services

TSA Disclosure statement: set of statements about the policies and practices of a TSA that particularly require

emphasis or disclosure to subscribers and relying parties, for example to meet regulatory requirements

TSA practice statement: statement of the practices that a TSA employs in issuing time-stamp

NOTE: This is a specific type of trust service practice statement as defined in ETSI EN 319 401 [4].

TSA system: composition of IT products and components organized to support the provision of time-stamping services

UTC(k): time scale realized by the laboratory "k" and kept in close agreement with UTC, with the goal to reach

±100 ns

NOTE: A list of UTC(k) laboratories is given in clause 1 of Circular T [i.6] disseminated by BIPM and available

from the BIPM website (https://www.bipm.org/).
3.2 Symbols
Void.
ETSI
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10 Draft ETSI EN 319 421 V1.2.0 (2023-01)
3.3 Abbreviations

For the purposes of the present document, the abbreviations given in ETSI EN 319 401 [4] and the following apply:

BIPM Bureau International des Poids et Mesures
BTSP Best practices Time-Stamp Policy
CA Certification Authority
IERS International Earth Rotation and Reference System Service
IT Information Technology
TAI International Atomic Time
TSA Time-Stamping Authority
TSP Trust Service Provider
TSU Time-Stamping Unit
UTC Co
...