ETSI TS 102 940 V2.1.1 (2021-07)

Intelligent Transport Systems (ITS); Security; ITS communications security architecture and security management; Release 2

RTS/ITS-00556

General Information

• Status: Not Published
• Technical Committee: ITS WG5 - Security
• Current Stage: 12 - Completion
• Due Date: 27-Jul-2021
• Completion Date: 22-Jul-2021

Standards Content (Sample)

ETSI TS 102 940 V2.1.1 (2021-07)






TECHNICAL SPECIFICATION
Intelligent Transport Systems (ITS);
Security;
ITS communications security architecture and
security management;
Release 2

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2 ETSI TS 102 940 V2.1.1 (2021-07)

Reference
RTS/ITS-00556
Keywords
interoperability, ITS, management, security
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ETSI

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3 ETSI TS 102 940 V2.1.1 (2021-07)
Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definition of terms, symbols, abbreviations and notation . 8
3.1 Terms . 8
3.2 Symbols . 8
3.3 Abbreviations . 8
3.4 Notation . 9
4 ITS reference architecture . 9
4.1 Background . 9
4.2 ITS applications groups . 10
4.2.1 ITS applications groups and their communication characteristics . 10
4.2.2 Cooperative awareness . 14
4.2.3 Static local hazard warning . 14
4.2.4 Interactive local hazard warning . 15
4.2.5 Area hazard warning . 15
4.2.6 Advertised services . 16
4.2.7 Local high-speed unicast service . 16
4.2.8 Local multicast service . 17
4.2.9 Low-speed unicast service . 17
4.2.10 Distributed (networked) service . 18
4.2.11 Multiple Applications . 18
4.3 Security requirements of ITS application groups . 18
4.3.1 Security requirements of cooperative awareness . 18
4.3.1.1 Authentication and Authorization . 18
4.3.1.2 Confidentiality . 19
4.3.1.3 Privacy . 19
4.3.2 Security requirements of static local hazard warnings . 19
4.3.2.1 Authentication and Authorization . 19
4.3.2.2 Confidentiality and Privacy . 19
4.3.3 Security requirements of interactive local hazard warnings . 19
4.3.3.1 Authentication and Authorization . 19
4.3.3.2 Confidentiality and Privacy . 19
4.3.4 Security requirements of area hazard warnings . 20
4.3.4.1 Authentication and Authorization . 20
4.3.4.2 Confidentiality and Privacy . 20
4.3.5 Security requirements of advertised services . 20
4.3.5.1 Authentication and Authorization . 20
4.3.5.2 Confidentiality and Privacy . 20
4.3.6 Security requirements of other services . 20
4.3.7 Security requirements of multiple applications. 20
4.3.7.1 Authentication and Authorization . 20
4.3.7.2 Confidentiality and Privacy . 20
5 ITS communications security architecture . 21
5.1 ITS station communications security architecture . 21
5.2 Security services . 22
5.3 ITS security functional model . 24
6 ITS station security management . 31
6.1 Basic principles . 31
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4 ETSI TS 102 940 V2.1.1 (2021-07)
6.2 Guidelines for establishing enrolment trust requirements . 31
6.3 Trust and privacy management . 32
6.4 Access control . 33
6.5 Identity management . 33
6.6 Confidentiality . 34
7 ITS Security management system . 35
7.0 General . 35
7.1 Certificate Trust List/multiple Root CAs . 37
7.2 Root CA . 42
7.3 Enrolment Authority. 43
7.4 Authorization Authority . 43
7.5 Trust List Manager . 44
7.6 Misbehaviour Authority . 44
Annex A (informative): Change history . 47
History . 48

ETSI

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5 ETSI TS 102 940 V2.1.1 (2021-07)
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 Technical Specification (TS) has been produced by ETSI Technical Committee Intelligent Transport Systems
(ITS).
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 ETSI TS 102 940 V2.1.1 (2021-07)
1 Scope
The present document specifies a security architecture for Intelligent Transport System (ITS) communications. Based
upon the security services defined in ETSI TS 102 731 [4], it identifies the functional entities required to support
security in an ITS environment and the relationships that exist between the entities themselves and the elements of the
ITS reference architecture defined in ETSI EN 302 665 [1].
The present document also identifies the roles and locations of a range of security services for the protection of
transmitted information and the management of essential security parameters. These include identifier and certificate
management, PKI processes and interfaces as well as basic policies and guidelines for trust establishment.
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] ETSI EN 302 665: "Intelligent Transport Systems (ITS); Communications Architecture".
[2] Void.
[3] Void.
[4] ETSI TS 102 731: "Intelligent Transport Systems (ITS); Security; Security Services and
Architecture".
[5] ETSI TS 102 941: "Intelligent Transport Systems (ITS); Security; Trust and Privacy
Management".
[6] ETSI TS 102 942: "Intelligent Transport Systems (ITS); Security; Access Control".
[7] ETSI TS 102 943: "Intelligent Transport Systems (ITS); Security; Confidentiality services".
[8] ETSI TS 103 097: "Intelligent Transport Systems (ITS); Security; Security header and certificate
formats".
[9] Void.
[10] ETSI EN 302 636-4-1: "Intelligent Transport Systems (ITS); Vehicular communications;
GeoNetworking; Part 4: Geographical addressing and forwarding for point-to-point and point-to-
multipoint communications; Sub-part 1: Media-Independent Functionality".
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.
ETSI

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7 ETSI TS 102 940 V2.1.1 (2021-07)
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 TR 102 638: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of
Applications; Release 2".
[i.2] ETSI TR 102 863: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of
Applications; Local Dynamic Map (LDM); Rationale for and guidance on standardization".
[i.3] IEEE 1609.3™ 2010: "Wireless Access in Vehicular Environments (WAVE) - Networking
Services".
[i.4] TS 16439: "Electronic fee collection - Security framework", (produced by CEN).
[i.5] ETSI TS 102 890-2: "Intelligent Transport Systems (ITS); Facilities layer function; Part 2:
Position and time facility specification".
[i.6] IETF RFC 4949: "Internet Security Glossary", Version 2, August 2007.
[i.7] ETSI TS 102 723-8: "Intelligent Transport Systems (ITS); OSI cross-layer topics; Part 8: Interface
between security entity and network and transport layer".
[i.8] C-ITS Platform WG5: "Security & Certification Final Report ANNEX 1: Trust models for
Cooperative - Intelligent Transport System (C-ITS)".
[i.9] Certificate Policy for Deployment and Operation of European Cooperative Intelligent Transport
Systems (C-ITS), Release 1, June 2017.
NOTE: Available at https://ec.europa.eu/transport/sites/transport/files/c-its_certificate_policy_release_1.pdf.
[i.10] ETSI TS 102 723-9: "Intelligent Transport Systems (ITS); OSI cross-layer topics; Part 9: Interface
between security entity and facilities layer".
[i.11] I. Mahmoudi, J. Kamel, A. Kaiser, I. Ben Jemaa, and P. Urien: "Towards a Reliable Machine
Learning Based Global Misbehavior Detection in C-ITS: Model Evaluation Approach", IWVSC,
2019.
[i.12] J. Kamel, F. Haidar, A. Kaiser, I. Ben Jemaa, B. Lonc, and P. Urien: "A
MisbehaviorAuthoritySystem for Sybil Attack Detectionin C-ITS", IEEE UEMCON, 2019.
[i.13] ETSI TR 103 460: "Intelligent Transport Systems (ITS); Security; Pre-standardization study on
Misbehavior Detection; Release 2".
[i.14] ETSI EN 302 637-2: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set
of Applications; Part 2: Specification of Cooperative Awareness Basic Service".
[i.15] ETSI EN 302 637-3: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set
of Applications; Part 3: Specifications of Decentralized Environmental Notification Basic
Service".
[i.16] ETSI TS 103 301: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of
Applications; Facilities layer protocols and communication requirements for infrastructure
services; Release 2".
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8 ETSI TS 102 940 V2.1.1 (2021-07)
3 Definition of terms, symbols, abbreviations and
notation
3.1 Terms
For the purposes of the present document, the terms given in ETSI TS 102 731 [4], IETF RFC 4949 [i.6] and the
following apply:
Certificate Revocation List (CRL): signed list indicating a set of certificates that are no longer considered valid by the
certificate issuer
Certificate Revocation List For Authorities (CRL CA): certificate revocation list issued by a Root CA which
contains revoked certificates of the subordinate CAs within the hierarchical trust domain managed by the Root CA or its
own Root CA certificates
certificate trust list: signed list indicating a set of trusted services of a PKI hierarchy controlled by a Root CA or a set
of trusted Root CAs within the C-ITS Trust Domain controlled by a top-level authority (Trust List Manager)
identifier: attribute or a set of attributes of an entity which uniquely identifies the entity within a certain context
security management: operations that support acquiring or establishing the validity of certificates for cooperative ITS
communications
3.2 Symbols
Void.
3.3 Abbreviations
For the purposes of the present document, the abbreviations given in ETSI EN 302 665 [1], ETSI TS 103 301 [i.16] and
the following apply:
AA Authorization Authority
CA Co-operative Awareness
CAM Co-operative Awareness Message
CCMS Cooperative-ITS security Certificate Management System
C-ITS Cooperative Intelligent Transport System
CN Co-operative Navigation
CPOC C-ITS Point Of Contact
CRL Certificate Revocation List
CS Communities Services
CSM Co-operative Speed Management
DENM Decentralized Environment Notification Message
EA Enrolment Authority
GN GeoNetworking
HSM Hardware Security Module
ID Identity
IDS Intrusion Detection System
IP Internet Protocol
IPS Intrusion Prevention System
IPv6 Internet Protocol version 6
ITS Intelligent Transport System
ITS-S ITS Station
LBS Location Based Services
LCM Life Cycle Management
MA Misbehaviour Authority
MAC Medium Access Control
MBD MisBehaviour Detection
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9 ETSI TS 102 940 V2.1.1 (2021-07)
MR Misbehaviour Report
OSI Open System Interconnect
PDA Personal Data Appliance
PKI Public Key Infrastructure
RHW Road Hazard Warning
RSU Road Side Unit
SAP Service Access Point
SOC Security Operational Center
TLM Trust List Manager
UML Unified Modeling Language
WAVE Wireless Access in Vehicular Environments
WSA WAVE Service Announcement
3.4 Notation
The requirements identified in the present document include:
a) mandatory requirements strictly to be followed in order to conform to the present document. Such
requirements are indicated by clauses without any additional marking;
b) requirements strictly to be followed if applicable to the type of ITS Station concerned.
For case b) requirements are indicated as follows:
• [Itss_WithPrivacy] is used to denote requirements applicable to ITS-S for which pseudonymity has to be
assured and re-identification by the AA is not allowed. This includes for instance personal user vehicle ITS-S
or personal ITS-S Portable.
• [Itss_NoPrivacy] is used to denote requirements applicable to ITS-S for which pseudonymity does not have to
be assured and are allowed to be re-identified by the AA. This may be for instance fixed or mobile RSUs or
special vehicles.
4 ITS reference architecture
4.1 Background
ETSI EN 302 665 [1] describes an ITS station architecture based upon four processing layers identified as follows:
• Access Layer;
• Networking & Transport Layer;
• Facilities Layer; and
• Applications Layer.
These horizontal layers are bounded on each side by a vertical Management entity and a Security entity (Figure 1).
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10 ETSI TS 102 940 V2.1.1 (2021-07)

Figure 1: ITS station architecture (from ETSI EN 302 665 [1])
The layers in this architecture do not represent directly the Open System Interconnect (OSI) protocol modelling layers
but the functionality expected in each can be mapped to OSI model quite simply. Having mapped the OSI protocol
layers to the ITS station architecture, this can be extended into an ITS communications architecture in which the
protocol layers communicate on a peer-to-peer basis as shown in Figure 2.

Figure 2: ITS communications architecture
4.2 ITS applications groups
4.2.1 ITS applications groups and their communication characteristics
ETSI TR 102 638 [i.1] defines the basic set of ITS applications which it divides into groups according to the
functionality provided. Based on this a further analysis in ETSI TR 102 863 [i.2] takes into account some additional
sources. The resulting list of functional groupings from this analysis is shown in Table 1. A more detailed description
can be found in ETSI TR 102 863 [i.2], clause A.1.
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11 ETSI TS 102 940 V2.1.1 (2021-07)
Table 1: ITS application classes
Applications Class Application Use case
Active road safety Driving assistance - Co-operative Awareness (CA) Emergency vehicle warning
Slow vehicle indication
Across traffic turn collision risk warning
Merging Traffic Turn Collision Risk
Warning
Co-operative merging assistance
Intersection collision warning
Co-operative forward collision warning
Lane Change Manoeuvre
Driving assistance - Road Hazard Warning (RHW) Emergency electronic brake lights
Wrong way driving warning
(infrastructure based)
Stationary vehicle - accident
Stationary vehicle - vehicle problem
Traffic condition warning
Signal violation warning
Roadwork warning
Decentralized floating car data -
Hazardous location
Decentralized floating car data -
Precipitations
Decentralized floating car data - Road
adhesion
Decentralized floating car data -
Visibility
Decentralized floating car data - Wind
Vulnerable road user Warning
Pre-crash sensing warning
Co-operative glare reduction
Cooperative traffic Co-operative Speed Management (CSM) Regulatory/contextual speed limits
efficiency notification
Curve Warning
Traffic light optimal speed advisory
Co-operative Navigation (CN) Traffic information and recommended
itinerary
Public transport information
In-vehicle signage
Co-operative local Location Based Services (LBS) Point of Interest notification
services
Automatic access control and parking
management
ITS local electronic commerce
Media downloading
Global internet Communities Services (CS) Insurance and financial services
services
Fleet management
Loading zone management
Theft related services/After theft vehicle
recovery
ITS station Life Cycle Management (LCM) Vehicle software/data provisioning and
update
Vehicle and RSU data calibration
Transport related electronic financial
transactions [i.4]
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12 ETSI TS 102 940 V2.1.1 (2021-07)
In order to define security classes the communication patterns of the different applications also need to be considered. Table 2 summarizes the communication behaviour of each
application.
Table 2: ITS applications communication behaviour
Use case Addressing Hops Frequency Direction Session
Emergency vehicle warnin
...