ETSI TR 102 893 V1.1.1 (2010-03)

Intelligent Transport Systems (ITS); Security; Threat, Vulnerability and Risk Analysis (TVRA)

DTR/ITS-0050005

General Information

• Status: Published
• Publication Date: 10-Mar-2010
• Technical Committee: ITS WG5 - Security
• Current Stage: 12 - Completion
• Due Date: 11-Mar-2010
• Completion Date: 11-Mar-2010

Standards Content (Sample)

Technical Report
Intelligent Transport Systems (ITS);
Security;
Threat, Vulnerability and Risk Analysis (TVRA)

2 ETSI TR 102 893 V1.1.1 (2010-03)

Reference
DTR/ITS-0050005
Keywords
ITS, security
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3 ETSI TR 102 893 V1.1.1 (2010-03)
Contents
Intellectual Property Rights . 6
Foreword . 6
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 7
3 Definitions and abbreviations . 8
3.1 Definitions . 8
3.2 Abbreviations . 8
4 The TVRA Method . 9
5 The ETSI Intelligent Transport System . 10
5.1 ITS architecture . 10
5.2 The Basic Set of Applications (BSA) . 11
5.2.1 BSA use case descriptions . 11
5.2.1.1 Stationary vehicle warning . 12
5.2.1.2 Traffic condition warning . 12
5.2.1.3 Signal violation warning . 12
5.2.1.4 Road work warning . 12
5.2.1.5 Collision risk warning from RSU. 12
5.2.1.6 Decentralized floating car data . 12
5.2.1.7 Regulatory/contextual speed limits . 12
5.2.1.8 Traffic information & recommended itinerary . 12
5.2.1.9 Limited access warning, detour notification . 12
5.2.1.10 In-vehicle signage . 12
5.2.1.11 Emergency vehicle warning . 12
5.2.1.12 Slow vehicle warning . 13
5.2.1.13 Motorcycle warning . 13
5.2.1.14 Emergency electronic brake lights . 13
5.2.1.15 Wrong way driving warning . 13
5.2.1.16 Traffic light optimal speed advisory . 13
5.2.1.17 Point of Interest notification . 13
5.2.1.18 Automatic access control and parking management . 13
5.2.1.19 Local electronic commerce . 13
5.2.1.20 Enhanced route guidance and navigation . 13
5.2.1.21 Media downloading . 13
5.2.1.22 Insurance and financial services . 13
5.2.1.23 Fleet management . 14
5.2.1.24 Automatic access control/parking access . 14
5.2.1.25 Vehicle software/data provisioning and update . 14
5.2.1.26 Personal data synchronization . 14
5.3 ITS communication services . 14
5.3.1 Cooperative Awareness Message (CAM) service. 16
5.3.1.1 General description . 16
5.3.1.2 Outgoing information . 17
5.3.1.3 Incoming information. 18
5.3.1.4 Local Dynamic Map (LDM) . 18
5.3.1.5 Information elements within CAM . 18
5.3.1.6 Procedure for outgoing messages . 18
5.3.1.7 Procedure for incoming messages . 18
5.3.2 Decentralized environmental Notification Message (DNM) service . 19
5.3.2.1 General description . 19
5.3.2.2 Outgoing information . 20
5.3.2.3 Incoming information. 20
5.3.2.4 LDM . 21
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5.3.2.5 Information elements within DNM messages . 21
5.3.2.6 Procedure for outgoing messages . 21
5.3.2.7 Procedure for incoming messages . 22
5.3.3 Local service advertisement service . 22
5.3.3.1 General description . 22
5.3.4 Internet-based service advertisement service . 22
5.3.4.1 General description . 22
6 ITS Security Objectives. 22
6.1 Confidentiality . 22
6.2 Integrity . 23
6.3 Availability . 23
6.4 Accountability . 23
6.5 Authenticity . 23
7 ITS Functional Security requirements . 23
7.1 Confidentiality . 24
7.2 Integrity . 24
7.3 Availability . 25
7.4 Accountability . 25
7.5 Authenticity . 25
8 ITS Target of Evaluation (ToE) . . 26
8.1 Assumptions on the ToE . 28
8.2 Assumptions on the ToE environment . 28
9 ITS system assets . 29
9.1 ITS station functional models . 29
9.2 Functional assets . 30
9.2.1 ITS-S (Vehicle) . 30
9.2.1.1 Protocol Control . 30
9.2.1.1.1 General description . 30
9.2.1.1.2 Vehicle to ITS infrastructure . 31
9.2.1.1.3 Vehicle to vehicle . 31
9.2.1.2 Service Control . 31
9.2.1.3 ITS Applications . 31
9.2.1.4 Sensor Monitor . 32
9.2.1.5 Vehicle System Control . 32
9.2.2 ITS-S (Roadside) . 33
9.2.2.1 Protocol Control . 33
9.2.2.1.1 General description . 33
9.2.2.1.2 RSU to vehicle . 33
9.2.2.1.3 RSU to ITS network . 33
9.2.2.2 Service Control . 33
9.2.2.3 ITS Applications . 34
9.2.2.4 Sensor Monitor . 34
9.2.2.5 Display Control . 34
9.3 Data assets . 35
9.3.1 ITS-S (Vehicle) . 35
9.3.1.1 Local Dynamic Map . 35
9.3.1.2 Local Vehicle Information . 35
9.3.1.3 Service Profile . 36
9.3.2 ITS-S (Roadside) . 36
9.3.2.1 Local Dynamic Map (LDM) . 36
9.3.2.2 Local Station Information . 37
9.3.2.3 Service Profile . 37
10 ITS threat analysis . 37
10.1 Attack interfaces and threat agents . 37
10.1.1 Attack interfaces and threat agents for ITS-S (Vehicle) ToE . 37
10.1.2 Attack interfaces and threat agents for ITS-S (Roadside) ToE . 38
10.2 Vulnerabilities and threats . 38
10.2.1 Threats to all ITS stations . 38
10.2.2 Availability . 39
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10.2.2.1 General threats to availability . 39
10.2.3 Integrity . 39
10.2.3.1 General threats to integrity . 39
10.2.4 Authenticity . 40
10.2.4.1 General threats to authenticity. 40
10.2.5 Confidentiality . 41
10.2.5.1 General threats to confidentiality . 41
10.2.6 General threats to accountability . 41
10.2.7 Vulnerabilities and threats . 41
10.2.7.1 Determining system vulnerabilities . 41
10.2.7.2 Threats and vulnerabilities within an ITS-S (Vehicle) . 42
10.2.7.3 Threats and vulnerabilities within an ITS-S (Roadside) . 49
10.3 Security risks in an ITS system . 55
10.3.1 Risks in an ITS-S (Vehicle) . 55
10.3.2 Risks in an ITS-S (Roadside) . 57
11 Countermeasures . 58
11.1 List of Countermeasures . 58
11.2 Evaluation of Countermeasures . 59
11.3 Countermeasure Analysis . 60
11.3.1 Reduce frequency of beaconing and other repeated messages . 60
11.3.2 Add source identification (IP address equivalent) in V2V messages . 60
11.3.3 Limit message traffic to V2I/I2V when infrastructure is available and implement message flow control
and station registration . 61
11.3.4 Implement frequency agility within the 5,9 GHz band . 62
11.3.5 Implement ITS G5A as a CDMA/spread-spectrum system . 62
rd
11.3.6 Integrate 3 Generation mobile technology into ITS G5A communications . 63
11.3.7 Digitally sign each message using a Kerberos/PKI-like token system . 64
11.3.7.1 Kerberos-like solution . 64
11.3.7.1.1 General requirements . 64
11.3.7.1.2 Countermeasure analysis . 65
11.3.7.2 PKI-like solution . 65
11.3.7.2.1 General requirements . 65
11.3.7.2.2 Countermeasure analysis . 65
11.3.8 Include a non-cryptographic checksum of the message in each message sent . 66
11.3.9 Remove requirements for message relay in the ITS BSA . 67
11.3.10 Include an authoritative identity in each message and authenticate it . 67
11.3.11 Use broadcast time (Universal Coordinated Time - UTC - or GNSS) to timestamp all messages . 68
11.3.12 Include a sequence number in each new message . 69
11.3.13 Use INS or existing dead-reckoning methods (with regular - but possibly infrequent - GNSS
corrections) to provide positional data . 70
11.3.14 Implement differential monitoring on the GNSS system to identify unusual changes in position . 70
11.3.15 Encrypt the transmission of personal and private data . 71
11.3.16 Implement a Privilege Management Infrastructure (PMI). . 72
11.3.17 Software authenticity and integrity are certified before it is installed . 73
11.3.18 Use a pseudonym that cannot be linked to the true identity of either the user or the user's vehicle . 73
11.3.19 Maintain an audit log of the type and content of each message sent to and from an ITS-S . 74
11.3.20 Perform plausibility tests on incoming messages . 75
11.3.21 Provide remote deactivation of misbehaving ITS-S (Vehicle) . 76
11.3.22 Use hardware-based identity and protection of software on an ITS-S . 76
11.4 Countermeasure Set . 77
11.4.1 ITS Countermeasure Set . 78
11.4.1.1 Countermeasures to Denial of Service (DoS) and availability threats . 78
11.4.1.2 Countermeasures to integrity threats . 80
11.4.1.3 Countermeasures to confidentiality and privacy threats. 80
11.4.1.4 Countermeasures to non-repudiation and accountability threats . 81
11.4.2 Residual risk . 81
Annex A: Cost - Benefit analysis of the selected countermeasures . 82
History . 86
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Intellectual Property Rights
IPRs essential or potentially essential to the present document 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
(http://webapp.etsi.org/IPR/home.asp).
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.
Foreword
This Technical Report (TR) has been produced by ETSI Technical Committee Intelligent Transport System (ITS).
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7 ETSI TR 102 893 V1.1.1 (2010-03)
1 Scope
The present document summarizes the results of a Threat, Vulnerability and Risk Analysis (TVRA) of 5,9 GHz radio
communications in an Intelligent Transport System (ITS). The analysis considers vehicle-to-vehicle and
vehicle-to-roadside network infrastructure communications services in the ITS Basic Set of Applications (BSA) [i.8]
operating in a fully deployed ITS.
The analysis in the present document considers issues of privacy implicitly with confidentiality. It does not consider
regulatory requirements for privacy
The present document was prepared using the TVRA method described in TS 102 165-1 [i.1].
NOTE: Whilst the present document is a technical report it identifies requirements for future work. In all cases these
requirements are considered indicative pending their ratification in formal ETSI Technical Specifications
within the ETSI ITS Work Programme.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the purposes
of the referring document;
- for informative references.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://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.
2.1 Normative references
The following referenced documents are indispensable for the application of the present document. For dated references,
only the edition cited applies. For non-specific references, the latest edition of the referenced document (including any
amendments) applies.
Not applicable.
2.2 Informative references
The following referenced documents are not essential to the use of the present document but they assist the user with regard
to a particular subject area. For non-specific references, the latest version of the referenced document (including any
amendments) applies.
[i.1] ETSI TS 102 165-1: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); Methods and protocols; Part 1: Method and proforma for Threat,
Risk, Vulnerability Analysis".
[i.2] ETSI TS 102 637-1: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of
Applications; Part 1: Functional Requirements.
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[i.3] ETSI TS 102 637-2: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of
Applications; Part 2: Specification of Co-operative Awareness Basic Service".
[i.4] ETSI TS 102 637-3: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of
Application; Part 3: Specification of Decentralized Environmental Notification Basic Service".
[i.5] ETSI EN 302 665: "Intelligent Transport Systems (ITS); Communications Architecture".
[i.6] ETSI TS 102 731: "Intelligent Transportation Systems (ITS); Security; Security Services and
Architecture".
[i.7] Brown, C. (Aalborg. 2007): "Vehicles as Sensors for Cooperative Systems". Presentation on ITS in
Europe.
[i.8] ETSI TR 102 638: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of
Applications; Definitions".
[i.9] IEEE 802.11 IEEE Standard for Information technology-Telecommunications and information
exchange between systems-Local and metropolitan area networks-Specific requirements -
Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications".
[i.10] ITU-T Recommendation X.509: "Information technology - Open Systems Interconnection - The
Directory: Public-key and attribute certificate frameworks".
[i.11] ETSI TS 102 637-4: "Intelligent Transport Systems (ITS); Vehicular Communications; Basic set of
applications; Part 4: Operational Requirements.".
[i.12] IETF RFC 4120: "The Kerberos Network Authentication Service (V5)".
NOTE: Available at http://tools.ietf.org/html/rfc4120.
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
beaconing: network layer service which retransmits requested information
End user: functional agent directly representing the human user of the ITS or the ITS service provider
geo-addressing: Network layer service that enables the addressing a specific geographic region.
ITS use case: specific scenario in which ITS messages are exchanged
ITS user: any ITS application or functional agent sending, receiving or accessing ITS-related information
ITS application: entity that defines and implements an ITS use case or a set of ITS use cases
local dynamic map: dynamically maintained information on driving and environmental conditions in the vicinity of the
ITS-S
restricted local ITS station data: data to be shared only with authorized parties
unrestricted local ITS station data: data that may be shared without requiring authorization from the recipient
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AA Attribute Authority
AC Attribute Certificate
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9 ETSI TR 102 893 V1.1.1 (2010-03)
BSA Basic Set of Applications
CAM Cooperative Awareness Message
CCH Control CHannel
CDMA Code Division Multiple Access
DNM Decentralized environmental Notification Message
FA Functional Asset
GNSS Global Navigation Satellite System
I2V Infrastructure to Vehicle
ITS Intelligent Transport System
ITS-G5A ITS radio signalling in the 5,875 GHz to 5,905 GHz frequency range
ITS-S ITS Station
LDM Local Dynamic Map
OS Operating System
OSI Open Systems Interconnection
PKC Public Key Cryptography
PKI Public Keying Infrastructure
PMI Privilege Management Infrastructure
PMI Privilege Management Infrastructure
RSU Road Side Unit
SAML Security Assertion Markup Language
SCH Service CHannel
ToE Target of Evaluation
TTP Trusted Third Party
TVRA Threat, Vulnerability and Risk Analysis
UTC Universal Coordinated Time
V2I Vehicle to Infrastructure
V2V Vehicle to Vehicle
VIN Vehicle Identification Number
4 The TVRA Method
Without an understanding of the threats posed to a system it is impossible to select or devise appropriate measures to
counter these threats. The ETSI Threat, Vulnerability and Risk Analysis (TVRA) [i.1] is used to identify risks to a system
by isolating the vulnerabilities of the system, assessing the likelihood of a malicious attack on that vulnerability and
determining the impact that such an attack will have on the system.
The TVRA method involves the following seven steps:
1) Identify security objectives.
2) Identify security requirements.
3) Produce an inventory of system assets.
4) Classify system vulnerabilities and threats.
5) Quantify the likelihood and impact of attack.
6) Determine the risks involved.
7) Specify detailed security requirements (countermeasures).
The present document summarizes the results from each of these steps in the analysis of the ETSI Intelligent Transport
System (ITS) standards.
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5 The ETSI Intelligent Transport System
5.1 ITS architecture
Intelligent Transport Systems comprise the following communicating entities (as shown in Figure 1):
• Vehicles
• Roadside units
• A network infrastructure
Figure 1: Communicating ITS entities
This simplified architecture can be represented in functional terms by the overlay shown in Figure 2.

Figure 2: ITS functional entities
For the purpose of the TVRA, reference points are named and mapped to the ITS functional model as shown in Figure 3.
The physical interface at reference point K may be implemented in a number of ways but, within the ITS functional model,
the reference point itself represents the direct management relationship that an in-vehicle ITS station may have with the ITS
infrastructure for the purpose of maintaining security parameters such as cryptographic keys.
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Figure 3: ITS functional model with reference points
The reference points indicated in Figure 3 are defined as follows:
• A describes the temporary relationship between two vehicles.
• B describes the temporary relationship between a vehicle and a roadside station.
• J describes the relationship between an ITS roadside station and the ITS network infrastructure.
• K describes the relationship between an ITS vehicle station and the ITS network infrastructure.
For the purpose of this TVRA, the interfaces at A and B are assumed to use communications in the 5,9 GHz band. It is also
assumed that the interface at K could be routed to the ITS infrastructure indirectly through a roadside station, also in the
5,9 GHz band.
5.2 The Basic Set of Applications (BSA)
The Basic Set of Applications (BSA) [i.1] represents the mandatory set of services to be deployed in an ITS station. The
BSA is described as a collection of traffic and transport use cases. For the purposes of the TVRA, these have been
re-specified in clause 5.3 as a much smaller set of communications services.
The use cases in the BSA and, thus, included in the TVRA are as follows:
1) Stationary vehicle warning - accident/vehicle problem.
2) Traffic condition warning (includes traffic jam ahead warning).
3) Signal violation warning (includes stop sign violation).
4) Road work warning.
5) Collision Risk Warning from RSU.
6) Decentralized Floating Car Data - Precipitations/Road Adhesion/Visibility/Wind.
7) Regulatory/Contextual speed limits.
8) Traffic information & Recommended itinerary.
9) Limited access, detour notification.
10) In-vehicle signage.
5.2.1 BSA use case descriptions
The following clauses provide a brief description of the use cases within the BSA. Communication patterns and message
repetition rates are specified in TS 102 637-1 [i.2] and TS 102 637-4 [i.11].
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5.2.1.1 Stationary vehicle warning
A stationary vehicle at a potentially dangerous location periodically sends out a warning to other vehicles. The information
may also be forwarded by available Road-Side Units (RSU) to a traffic management centre.
5.2.1.2 Traffic condition warning
Warning other vehicles about a detected potentially dangerous traffic condition.
5.2.1.3 Signal violation warning
When a signal violation is detected, all potentially affected vehicles are warned. The detection is done in the road side unit.
NOTE: Use cases 5.2.1.3 and 5.2.1.5 are similar
5.2.1.4 Road work warning
A mobile road infrastructure component distributes messages to warn affected vehicles about road works.
5.2.1.5 Collision risk warning from RSU
Detect potential collisions of vehicles that cannot directly communicate and warn the drivers.
NOTE: Use cases 5.2.1.3 and 5.2.1.5 are similar
5.2.1.6 Decentralized floating car data
Detect potential local dangers and send out warning message to potentially affected vehicles. Different warning reasons can
be precipitation, road adhesion, visibility, or wind.
5.2.1.7 Regulatory/contextual speed limits
Road side infrastructure broadcasts speed limits that can be
• regulatory, i.e. set by an authority; or
• contextual, e.g. reduced limit due to rain.
NOTE: Use cases 5.2.1.7 and 5.2.1.10 are the same.
5.2.1.8 Traffic information & recommended itinerary
Broadcast traffic conditions. May also cause vehicles to download the recommended itinerary over a different channel.
5.2.1.9 Limited access warning, detour notification
Broadcast access restrictions, e.g. due to road works. May also provide detour advice in the same messages.
5.2.1.10 In-vehicle signage
Traffic sign information is broadcasted to be displayed in the vehicle.
NOTE: Use cases 5.2.1.7 and 5.2.1.10 are the same.
5.2.1.11 Emergency vehicle warning
An emergency vehicle periodically broadcasts its position, speed and heading as well as whether it has its siren on and/or
its blue light (or equivalent) in use.
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5.2.1.12 Slow vehicle warning
A slow vehicle periodically broadcasts its presence and thus encourages other vehicles to overtake. The broadcast
information contains an indication that this is a special type of vehicle, called "slow vehicle".
5.2.1.13 Motorcycle warning
A motorcycle periodically broadcasts its presence. If other vehicles detect the imminent danger of collision, a warning is
issued. The information broadcast contains an indication that this is a special type of vehicle, called "motorcycle".
5.2.1.14 Emergency electronic brake lights
Warn vehicles behind of a sudden slowdown. Broadcast respective message.
5.2.1.15 Wrong way driving warning
Warn vehicles in front of a detected violation of a one-way road. Broadcast respective message.
5.2.1.16 Traffic light optimal speed advisory
A traffic light to broadcasts timing data associated with its current state (e.g. time remaining before switching between
green, amber and red).
5.2.1.17 Point of Interest notification
Road side unit periodically sends information about local services. The vehicle may establish a unicast connection to
request more information.
NOTE: Use cases 5.2.1.17 through 5.2.1.19 are similar and mainly distinguished by the protocols used over the
transparent communication channel.
5.2.1.18 Automatic access control and parking management
A road side unit periodically broadcasts the presence of an access controlled area. Vehicles requiring access provide
credentials authorizing the access in unicast communications.
5.2.1.19 Local electronic commerce
A road side unit periodically broadcasts the presence of local electronic commerce. Vehicles requiring access provide
credentials authorizing the access in unicast communications.
5.2.1.20 Enhanced route guidance and navigation
Road side unit periodically sends service announcements containing links to "known navigation support servers".
NOTE: Use cases 5.2.1.20 through 5.2.1.26 are similar and mainly distinguished by the type of service advertised
and the respective service protocols.
5.2.1.21 Media downloading
A road side unit periodically broadcasts the presence of the possibility to download media files. Vehicles establish a unicast
connection and download required media data.
5.2.1.22 Insurance and financial
...