ETSI TS 102 723-9 V1.1.1 (2021-03)

Intelligent Transport Systems (ITS); OSI cross-layer topics; Part 9: Interface between security entity and facilities layer

DTS/ITS-00553

General Information

• Status: Not Published
• Technical Committee: ITS WG5 - Security
• Current Stage: 12 - Completion
• Due Date: 04-Mar-2021
• Completion Date: 09-Mar-2021
• Mandate: M/453

Standards Content (Sample)

ETSI TS 102 723-9 V1.1.1 (2021-03)






TECHNICAL SPECIFICATION
Intelligent Transport Systems (ITS);
OSI cross-layer topics;
Part 9: Interface between security entity and facilities layer

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2 ETSI TS 102 723-9 V1.1.1 (2021-03)



Reference
DTS/ITS-00553
Keywords
adaption, addressing, interface, ITS, security
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3 ETSI TS 102 723-9 V1.1.1 (2021-03)
Contents
Intellectual Property Rights . 6
Foreword . 6
Modal verbs terminology . 6
Introduction . 6
1 Scope . 8
2 References . 8
2.1 Normative references . 8
2.2 Informative references . 8
3 Definition of terms, symbols and abbreviations . 9
3.1 Terms . 9
3.2 Symbols . 9
3.3 Abbreviations . 9
4 Architecture . 10
4.1 General . 10
4.1.1 Introduction. 10
4.1.2 Vertical message flow . 10
4.1.3 Horizontal control communication . 11
4.1.4 Protocol work split . 12
4.1.5 Multiple instances . 12
4.1.6 Error handling . 12
4.2 Security services . 12
5 Interfaces between the Security entity and the Facilities layer . 13
5.1 Interface services . 13
5.2 Service primitives and parameters . 14
5.2.1 SF-SIGN . 14
5.2.1.1 Description . 14
5.2.1.2 SF-SIGN.request . 14
5.2.1.3 SF-SIGN.confirm . 15
5.2.2 SF-VERIFY . 15
5.2.2.1 Description . 15
5.2.2.2 SF-VERIFY.request . 15
5.2.2.3 SF-VERIFY.confirm . 15
5.2.3 SF-ENCRYPT . 16
5.2.3.1 Description . 16
5.2.3.2 SF-ENCRYPT.request . 16
5.2.3.3 SF-ENCRYPT.confirm . 17
5.2.4 SF-DECRYPT . 17
5.2.4.1 Description . 17
5.2.4.2 SF-DECRYPT.request . 17
5.2.4.3 SF-DECRYPT.confirm . 17
5.2.5 SF-IDCHANGE-SUBSCRIBE . 17
5.2.5.1 Description . 17
5.2.5.2 SF-IDCHANGE-SUBSCRIBE.request . 18
5.2.5.3 SF-IDCHANGE-SUBSCRIBE.confirm. 18
5.2.6 SF-IDCHANGE-EVENT . 18
5.2.6.1 Description . 18
5.2.6.2 SF-IDCHANGE-EVENT.indication . 18
5.2.6.3 SF-IDCHANGE-EVENT.response . 18
5.2.7 SF-IDCHANGE-UNSUBSCRIBE . 19
5.2.7.1 Description . 19
5.2.7.2 SF-IDCHANGE-UNSUBSCRIBE.request . 19
5.2.7.3 SF-IDCHANGE-UNSUBSCRIBE.confirm . 19
5.2.8 SF-IDCHANGE-TRIGGER . 19
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4 ETSI TS 102 723-9 V1.1.1 (2021-03)
5.2.8.1 Description . 19
5.2.8.2 SF-IDCHANGE-TRIGGER.request . 19
5.2.8.3 SF-IDCHANGE-TRIGGER.confirm . 19
5.2.9 SF-ID-LOCK . 20
5.2.9.1 Description . 20
5.2.9.2 SF-ID-LOCK.request . 20
5.2.9.3 SF-ID-LOCK.confirm . 20
5.2.10 SF-ID-UNLOCK . 20
5.2.10.1 Description . 20
5.2.10.2 SF-ID-UNLOCK.request . 20
5.2.10.3 SF-ID-UNLOCK.confirm . 20
5.2.11 SF-LOG-SECURITY-EVENT . 21
5.2.11.1 Description . 21
5.2.11.2 SF-LOG-SECURITY-EVENT.request message example . 21
5.2.11.3 SF-LOG-SECURITY-EVENT.confirm message example . 23
5.2.12 SF-ENCAP . 23
5.2.12.1 Description . 23
5.2.12.2 SF-ENCAP.request . 23
5.2.12.3 SF-ENCAP.confirm . 24
5.2.13 SF-DECAP . 24
5.2.13.1 Description . 24
5.2.13.2 SF-DECAP.request . 24
5.2.13.3 SF-DECAP.confirm . 25
6 SF-SAP procedures . 25
6.1 Outbound message handling. 25
6.1.1 Using SF-SIGN, SF-ENCRYPT . 25
6.1.2 Using SF-ENCAP . 26
6.2 Inbound message handling . 26
6.2.1 Using SF-VERIFY and SF-DECRYPT . 26
6.2.2 Using SF-DECAP . 27
6.3 ID Management . 27
6.3.1 IDCHANGE Notifications . 27
6.3.1.1 Introduction . 27
6.3.1.2 Id-change event hook . 28
6.3.1.3 Two phase commit process . 28
6.3.2 Prevent IDCHANGES . 30
6.3.3 Trigger IDCHANGES . 31
6.4 Log security event . 31
Annex A (informative): SF-Command . 32
A.1 Overview . 32
A.2 Description . 32
A.2.1 SF-IDCHANGE-EVENT service: SF-COMMAND.request (see clause 5.2.6.2) . 32
A.2.2 SF-IDCHANGE-EVENT service: SF-COMMAND.confirm (see clause 5.2.6.3) . 33
Annex B (informative): SF-Request . 34
B.1 Overview . 34
B.2 Description . 34
B.2.1 SF-ENCRYPT service: SF-REQUEST.request (see clause 5.2.3.2) . 34
B.2.2 SF-ENCRYPT service: SF-REQUEST.confirm (see clause 5.2.3.3) . 35
Annex C (informative): Example of service primitives description in the framework of
ISO 24102-3 . 36
C.1 Introduction . 36
C.2 Class for SF-SAP Command.request service primitive functions . 36
C.3 Class for SF-SAP Command.confirm service primitive functions . 36
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5 ETSI TS 102 723-9 V1.1.1 (2021-03)
C.4 Class for SF-SAP Request.request service primitive functions . 37
C.5 Class for SF-SAP Request.confirm service primitive functions . 37
History . 38

ETSI

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6 ETSI TS 102 723-9 V1.1.1 (2021-03)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is 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 IPR Policy, no investigation, 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.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Intelligent Transport Systems
(ITS).
The present document is part 9 of a multi-part deliverable. Full details of the entire series can be found in part 1 [i.2].
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.
Introduction
The communications architecture standard ETSI EN 302 665 [i.1], clause 4.4 describes the reference architecture of ITS
station, which includes the following internal functional blocks:
• ITS-S Access layer;
• ITS-S Networking & Transport layer;
• ITS-S Facilities layer;
• ITS-S Applications;
• ITS-S Management entity;
• ITS-S Security entity;
and the interfaces between these blocks.
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7 ETSI TS 102 723-9 V1.1.1 (2021-03)
The present document specifies interfaces between the security entity and facilities layer of ITS-S from a functional
point of view. Access control to the Service Access Point and further definitions of station internal signals are out of
scope of the present document.
The SAP specification is specific to the ITS architecture but generic to the concrete technologies used.
The present document is structured in the following way:
• First, the architecture integration is outlined.
• Secondly, functionalities are collected from related standards and mapped to service primitives.
• Finally, the use of service primitives in procedures is described.
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8 ETSI TS 102 723-9 V1.1.1 (2021-03)
1 Scope
The present document specifies interfaces between the ITS Security entity and the ITS Facilities layer including
interface services and service primitives which are extensible in order to achieve general applicability. Additionally, it
specifies related procedures and common parameters.
The SF-SAP description in the present document is from a functional point of view according to the ISO model
modified by ETSI EN 302 665 [i.1].
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 TS 102 940: "Intelligent Transport Systems (ITS); Security; ITS communications security
architecture and security management".
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 302 665: "Intelligent Transport Systems (ITS); Communications Architecture".
[i.2] ETSI TS 102 723-1: "Intelligent Transport Systems (ITS); OSI cross-layer topics; Part 1:
Architecture and addressing schemes".
[i.3] ISO 24102-3: "Intelligent transport systems -- Communications access for land mobiles (CALM) -
- ITS station management -- Part 3: Service access points".
[i.4] ETSI TS 103 097: "Intelligent Transport Systems (ITS); Security; Security header and certificate
formats".
[i.5] ETSI TS 102 637-1: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set
of Applications; Part 1: Functional Requirements".
[i.6] ETSI TS 101 539-2: "Intelligent Transport Systems (ITS); V2X Applications; Part 2: Intersection
Collision Risk Warning (ICRW) application requirements specification".
[i.7] ETSI TS 101 539-3: "Intelligent Transport Systems (ITS); V2X Applications; Part 3: Longitudinal
Collision Risk Warning (LCRW) application requirements specification".
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9 ETSI TS 102 723-9 V1.1.1 (2021-03)
[i.8] PRESERVE Deliverable D1.3: "V2X Security Architecture V2", January 2014.
NOTE: Available at https://www.preserve-project.eu/www.preserve-project.eu/sites/preserve-
project.eu/files/PRESERVE-D1.3-V2X_Security_Architecture_V2.pdf.
[i.9] H. Schweppe, B. Weyl, Y. Roudier, M.S. Idrees, T. Gendrullis, M. Wolf: "Securing car2X
applications with effective hardware-software co-design for vehicular on-board networks".
th
In 27 Joint VDI/VW Automotive Security Conference, Berlin, Germany, October 2011.
VDI Berichte 2131.
NOTE: Available at https://evita-project.org/Publications/SGIR11.pdf.
[i.10] ETSI EN 302 663: "Intelligent Transport Systems (ITS); ITS-G5 Access layer specification for
Intelligent Transport Systems operating in the 5 GHz frequency band".
[i.11] ETSI EN 303 613: "Intelligent Transport Systems (ITS); LTE-V2X Access layer specification for
Intelligent Transport Systems operating in the 5 GHz frequency band".
[i.12] ETSI TS 101 539-1: "Intelligent Transport Systems (ITS); V2X Applications; Part 1: Road Hazard
Signalling (RHS) application requirements specification".
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the terms given in ETSI EN 302 665 [i.1], ETSI TS 102 940 [1] and the
following apply:
security association: addressing information and 'security material' for connecting to the 'security management entity'
NOTE: This corresponds to 'enrolment authorities' and 'authorization authorities'.
security entity: functional entity inside an ITS station which offers 'security mechanisms'
security protocol: protocol used to encode and decode 'security material' and messages between ITS Stations
3.2 Symbols
Void.
3.3 Abbreviations
For the purposes of the present document, the abbreviations given in ETSI EN 302 665 [i.1], ETSI TS 102 940 [1] and
the following apply:
SAP Service Access Point
SF-SAP Security entity - Facilities layer SAP
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10 ETSI TS 102 723-9 V1.1.1 (2021-03)
4 Architecture
4.1 General
4.1.1 Introduction
Figure 1 shows the ITS station reference architecture, as defined in ETSI EN 302 665 [i.1]. The present document
contains the specification of the Service Access Points (SAP), connecting the security entity and the facilities layer,
i.e. SF-SAP.

Figure 1: ITS station reference architecture
Interaction between the security entity and the layers may follow two principles. First, the vertical message flow
through the layers from top to bottom or vice versa. Secondly, the horizontal control communication from the security
entity towards the corresponding layer. Both are described in clauses 4.1.2 and 4.1.3.
4.1.2 Vertical message flow
Figure 2 extends the ITS station reference architecture by illustrating the overall information flow through the layers,
from originating application on the left hand side, to the receiving application on the right hand side.

Figure 2: TX (left) and RX (right) information flow through the ITS station
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11 ETSI TS 102 723-9 V1.1.1 (2021-03)
The present document specifies only the SF-SAP, therefore only a subset of the ITS station reference architecture has to
be taken into account. Figure 3 shows the typical information flow between any sending (TX) and receiving (RX) party,
with regard to the SF-SAP only. The Security entity acts like a layer inside the Facilities layer, i.e. it is called during the
processing of messages traversing the Facilities layer. The security entity will however not act as a layer above or below
the Facilities layer. This means that interactions with Applications and Network & Transport layers are achieved via
other means, i.e. the FA-SAP is used for the interaction between the Facilities and Applications layers, whereas the
NF-SAP is used for the interaction between the Networking & Transport layers and Facilities
...