AVES – Automated Vehicle Safety and Security Analysis
Framework
Giedre Sabaliauskaite
Lin Shen Liew
Fengjun Zhou
iTrust Centre for Research in Cyber
Security, Singapore University of
Technology and Design
Singapore
[email protected]
iTrust Centre for Research in Cyber
Security, Singapore University of
Technology and Design
Singapore
[email protected]
iTrust Centre for Research in Cyber
Security, Singapore University of
Technology and Design
Singapore
[email protected]
ABSTRACT
Automated Vehicle (AV) safety and cybersecurity is an important
issue that has to be adequately addressed to ensure that AVs are
ready to drive on public roads, and that they are able to safely and
efficiently coexist with other motorized and non-motorized traffic
participants. So far, there are numerous challenges, such as lack of
international standards, software and hardware limitations, absence
of methods for integrated safety and security analysis, etc. This
paper proposes a novel approach, AVES Framework, for systematic, model-based, integrated AV safety and cybersecurity analysis.
AVES Framework adheres to road vehicle development lifecycle
and is consistent with international and national standards. It is a
flexible method and may be used to analyze any AV regardless of its
automation and connectivity level. Furthermore, several relationship matrices and a Safety and Cyber Security Deployment (SCSD)
Model, inspired by the Quality Function Deployment method, are
used in AVES Framework for relationship analysis and decision
making with respect to safety and cybersecurity requirements, measures, and system components.
KEYWORDS
automated vehicle, safety, cybersecurity, ISO 26262, SAE 3016, SAE
3061, TR 68, Quality Function Deployment
ACM Reference Format:
Giedre Sabaliauskaite, Lin Shen Liew, and Fengjun Zhou. 2019. AVES ś
Automated Vehicle Safety and Security Analysis Framework. In Proceedings
of ACM Conference (Conference’17). ACM, New York, NY, USA, 8 pages.
https://doi.org/10.1145/nnnnnnn.nnnnnnn
1
INTRODUCTION
Automated vehicles (AVs) are gradually turning into reality, thanks
to the rapid advancement of Internet of Things and Artificial Intelligence. Expectations are high, among those motivating the development of AVs, that the road users will get to enjoy better mobility
and increased safety on the road.
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https://doi.org/10.1145/nnnnnnn.nnnnnnn
However, can we trust AVs? Are AVs safe, secure, and ready to
efficiently coexist with other motorized (motorbikes, buses, etc.)
and non-motorized (pedestrians, bicyclists, etc.) traffic participants?
Recent accidents involving AVs have raised some doubts about
the AV safety. Security is another important concern, since in addition to failures AVs are vulnerable to cyberattacks [4, 5, 7, 11, 14]. A
successful attack could lead to various safety, operational, financial,
or privacy losses [2]. This indicates that AV safety and cybersecurity are inter-dependent, and therefore should be analyzed in a
consistent and integrated way.
In AVs, driving automation is implemented using the Automated
Driving System (ADS) ś the hardware and software collectively
capable of performing automated driving functions [2]. There are
numerous challenges related to ADS safety and cybersecurity analysis. Firstly, there are five levels of driving automation, as defined
by the SAE J3016 standard [1], ranging from driver assistance (level
1) to full driving automation (level 5). An AV can be designed to
perform at one or several driving automation levels. More precisely,
multiple ADS applications ś features ś can be implemented in a single AV, each associated with a particular level of driving automation
and operational environment [2].
In addition, AVs can operate in isolation, or can communicate
with other vehicles, road infrastructure, and personal devices. Based
on connectivity level, we can define two types of AVs: autonomous
AVs (AVs that operate in isolation from other vehicles, using their
internal sensors to "see" the environment) and Extended Automated
Vehicles (ExAVs) (AVs that extend beyond the physical boundary
of the road vehicle and consist of road vehicle, off-board systems,
external interfaces and the data communication between AV and
off-board systems [8]).
Furthermore, ADS has numerous design constraints, as described
in [13]. Six classes of constraints have been identified, such as performance, predictability, storage, thermal, power, and others. These
constraints have to be considered during AV safety and security
analysis.
Finally, there is a lack of international standards for addressing
AV safety and security due to the novelty of AV domain. Available
standards are not sufficient for highly automated vehicles [10].
Furthermore, they treat safety and security separately.
ISO 26262 [9] and ISO/PAS 21448 [10] have been developed for
addressing road vehicle safety needs. Two types of safety are defined for road vehicles: functional safety (ISO 26262) and Safety Of
The Intended Functionality (SOTIF) (ISO/PAS 21448). Functional
safety is the absence of unreasonable risk due to hazards caused
by malfunctioning behavior of electric/electronic systems; SOTIF
Conference’17, July 2017, Washington, DC, USA
Connectivity level
Autonomous
vehicle
Extended
vehicle
Automation level
1
2
3
AVES
Framework
4
5
Figure 1: AVES Framework scope.
ś absence of unreasonable risk due to hazards caused by intended
functionality (e.g. inability of the function to correctly comprehend the situation) or performance limitations [10]. Both of these
standards are primarily developed for vehicles that could include
some driver assistance system, however, are not sufficient for highly
automated vehicles [10].
To address vehicle security needs, the SAE J3061 standard has
been developed [2]. It defines cybersecurity lifecycle of cyberphysical vehicle systems. However, the security lifecycle, defined
in SAE J3061, is analogous to the vehicle safety lifecycle described
in ISO 26262, and therefore, it is not sufficient for higly automated
vehicle cybersecurity analysis. ISO and SAE are currently jointly
developing ISO 21434 [3] standard, which will replace SAE J3061
in 2019.
In Singapore, a technical reference TR 68 for autonomous vehicles has been published in 2019 [16]. It consists of four parts, which
include basic AV behaviours (Part 1), safety (Part 2), cybersecurity
(Part 3), and vehicular data (Part 4). In this standard safety and
security are considered separately as well.
How can we analyze AV safety and cybersecurity in a consistent
and integrated way throughout entire vehicle development lifecycle,
taking into consideration the aforementioned challenges?
We propose a new approach AVES ś Automated Vehicles Safety
and Security Analysis Framework. It consists of several stages,
distributed across AV development lifecycle, which facilitate AV
safety and cybersecurity analysis. Four relationship matrices and a
Safety and Cyber Security Deployment (SCSD) Model are used by
the AVES Framework to help in decision making and managing AV
safety and cybersecurity.
The remainder of this paper is structured as follows. Section 2
presents an overview of the AVES Framework. Relationship matrices and SCSD Model are described in Section 3. Finally, Section 4
concludes the paper and describes our future work.
2
AVES FRAMEWORK
AVES Framework is developed with the intent to achieve the following objectives: firstly, it should be consistent with the aforementioned international and national road vehicle safety and security
Sabaliauskaite, et al.
standards; secondly, it must adhere to vehicle development lifecycle;
lastly, it should enable integrated Safety and Cyber Security (S&CS)
analysis of an AV at any vehicle automation and connectivity levels,
as depicted in Fig. 1.
Fig. 2 shows the main stages of the AVES Framework, which are
described in more detail in Table 1. As we can see from Fig. 2 and
Table 1, AVES Framework consists of 11 stages distributed throughout the entire vehicle lifecycle, which includes concept, product
development, production, operation, service, and decommissioning
phases.
AVES Framework starts with development of high-level AV specifications (Stage 1) at concept phase, needed for high-level safety
and cybersecurity analysis, requirement specification and risk evaluation (Stage 2), and measure selection (Stage 3) (see Fig. 2). Once
we are satisfied with the outcome of the analysis at the concept
phase, we can move to the product development phase and perform
similar activities at a more detailed and technical level (Stages 4-6).
Integrated AV safety and cybersecurity analysis, performed in
Stages 2 and 4, is based on the System-Theoretic Process Analysis
(STPA) [12]. Its description is out of scope of this paper.
There are feedback loops between stages, as shown in Fig. 2, to
address the changes/modifications that have to be performed in
previous stages. For example, if we are not able to select a satisfactory set of safety and security measures to implement safety
and security requirements in Stage 3, we need to return to Stage 2
and modify the requirements. If we are not able to do so using the
existing AV design (specifications developed in Stage 1), we need to
return to Stage 1 and modify AV design. After that, it is necessary
to repeat Stages 2 and 3.
Finally, at the end of product development phase, once the S&CS
analysis is completed and risk level is acceptable, we are able to
construct the SCSD Model (Stage 7), which is the main source of
information for analyzing AV safety and security during subsequent
AV lifecycle phases, such as production, operation, service, and
decommissioning (AVES Stages 8-11). During these phases, we
normally do not have full access to the information from concept
and product development phases. Thus, SCSD Model could provide
a sufficient amount of information required for S&CS analysis in
these phases.
3
RELATIONSHIP MATRICES AND SCSD
MODEL
Relationship matrices and SCSD Model are inspired by the principles of Quality Function Deployment (QFD) [6]. QFD was developed
in Japan in 1960s as a systematic method for structured product
planning and development. Fundamentally, QFD is a process or
methodology that utilizes a series of matrices to transform qualitative customer requirements into detailed engineering specifications
hence plans so that the end product can satisfy those requirements.
Besides proven effective in reducing development time and cost,
QFD is also a tool useful for recording the considerations/decisions
made during the product development process, which may facilitate
cross-functional communication and discussion [6].
QFD matrix, namely House of Quality (HoQ), displays the relationships between dependent (WHATs) and independent (HOWs)
Concept
Architecture
AVES – Automated Vehicle Safety and Security Analysis Framework
Stage 1.
Concept-level AV
specification
Conference’17, July 2017, Washington, DC, USA
Specifications
High-level S&CS
requirements
and risk levels
Stage 2.
Concept-level
S&CS analysis and
risk evaluation
Changes
Stage 3.
S&CS measure
selection and
conflict analysis
Changes
S&CS measures
Changes
No
Analysis results
Design
Specifications
Stage 4.
Detailed AV
specification
Initial S&CS
measures
Specifications
Stage 5.
Technical-level
S&CS analysis and
risk evaluation
Technical S&CS
requirements
and risk levels
Changes
Product Development
Prototype
No
Risk level acceptable?
Stage 8.
S&CS analysis during
production phase
using SCSD Model
Legend:
Yes
Stage 7.
SCSD Model construction
Stage 9.
S&CS analysis during
operation phase
using SCSD Model
Decommissioning
Service
S&CS measures and
software/hardware
components
Changes
Vehicle
Operation
Stage 6.
S&CS measure
revision and
implementation
Changes
S&CS
requirements
Production
Risk level acceptable?
Yes
workflow between stages
Stage 10.
S&CS analysis during
service phase using
SCSD Model
feedback
Stage 11.
S&CS analysis during
decommissioning phase
using SCSD Model
information transfer
Figure 2: Stages of the AVES Framework.
variables. WHATs are included as rows of HoQ, while HOWs ś as
columns.
Typically, QFD process begins with defining the customer requirements and mapping them on the design requirements using a
relationship matrix. Such a matrix helps to select design requirements. Then, cascading matrices could be constructed to map design
requirements to engineering design, engineering design to product
characteristics, and so on.
We use QFD-style matrices in AVES Framework for relationship
analysis and decision making with respect to safety and cybersecurity requirements, safety and security measures, and system
components.
Five matrices are used in AVES Framework:
• Matrix 1: S&CS Requirement Conflicts ś helps to analyze relationships between safety and cybersecurity requirements;
• Matrix 2: S&CS Requirement Coverage ś helps in selecting
safety and cybersecurity measures to satisfy S&CS requirements;
• Matrix 3: S&CS Measure Relationships ś helps to analyze
relationships between safety and cybersecurity measures;
• Matrix 4: S&CS Measure Implementation ś helps to assign
software/hardware components to safety and cybersecurity
measures;
• SCSD Model: a meta-matrix, which incorporates Matrices
1-4.
The workflow of Matrices 1-4 is shown in Fig. 3, and the SCSD
Model structure is depicted in Fig. 4. Matrix 1 is constructed in
AVES Stages 2 and 5, while Matrices 2, 3 and 4 ś Stages 3 and 6.
Finally, SCSD Model is constructed in Stage 7.
As we can see from Fig. 3, there is a correlation between Matrices 1-4: a matrix’s column headers (the HOWs) shall conditionally
become the subsequent matrix’ row headers (the WHATs). Furthermore, there are feedback loops to previous matrices to enable
revision of the input information, if necessary. For example, if the
conflicts between safety and cybersecurity measures cannot be
solved in Matrix 3, it is necessary to return to Matrix 2 and select
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Sabaliauskaite, et al.
Table 1: Summary of 11 stages of AVES Framework
Stage Title
No.
Description
1
AV specifications (descriptions, diagrams, etc.), needed for performing S&CS
analysis in Stage 2, are prepared.
AV S&CS analysis is performed using the specifications defined in Stage 1 as
an input. Hazards and threats are identified, their risk levels are evaluated,
and high-level S&CS requirements are defined. Matrix 1 is used to analyze
conflicts between requirements.
S&CS measures are selected based on high-level requirements defined in
Stage 2, and the analysis of possible conflicts between S&CS measures is
performed. Matrix 2 is used to facilitate measure selection, while Matrix 3 ś
to analyze relationships between measures, and Matrix 4 ś to assign system
components to measures. Matrix construction can be skipped if there is no
sufficient information on S&CS measures and components available yet.
2
Concept-level AV specification
Concept-level S&CS analysis and risk evaluation
3
S&CS measure selection and
conflict analysis
4
Detailed AV specification
5
6
7
Lifecycle
phase
Detailed models and descriptions, needed for performing S&CS analysis in
Stage 5, are developed, using AV design documentation and information Product
received from Stages 1 and 3.
development
Technical-level S&CS analy- AV S&CS analysis is performed using the specifications defined in Stage 4 and
sis and risk evaluation
high-level analysis results from Stage 2. Hazards and threats are identified,
their levels are evaluated, and technical S&CS requirements are defined. Matrix
1 is used to analyze conflicts between requirements.
S&CS measure revision and S&CS measures are selected based on technical S&CS requirements defined in
implementation
Stage 5; the analysis of possible conflicts between S&CS measures is performed.
Matrix 2 is used to facilitate measure selection, while Matrix 3 ś to analyze
relationships between measures, and Matrix 4 ś to assign software/hardware
components to measures.
SCSD (Safety and Cyber Security Deployment) Model is constructed based
SCSD Model construction
on the artefacts of previous stages. (SCSD model is explained in Section 3)
8,9, S&CS analysis using SCSD
10,11 Model
The SCSD Model is used to handle any hazards or security threats, which
might occur after product development phase has been completed.
another set of measures that satisfy the safety and cybersecurity requirements, and then to analyze the relationships of newly selected
measures in Matrix 3.
The following subsections include detailed description of all
matrices.
Matrix 1
Matrix 1 is constructed in AVES Stages 2 and 5, where AV hazards and threats are identified, their risks are evaluated, and S&CS
requirements are defined. The S&CS requirements are to be both
row headers and column headers of Matrix 1, as shown in Fig. 5.
This matrix serves to capture the relationships that exist between
requirements, using symbols shown in Table 2. Note that each cell
(i.e. intersection of row and column) may be empty or contain only
one symbol. The additional rows appended to Matrix 1, as depicted
in Fig. 5, are described in Table 3.
This matrix is used in the following way. All safety and cybersecurity requirements, identified in the analysis phase, are included
Production,
Operation,
Service and
Decommissioning.
Table 2: Symbols used in Matrix 1 to denote the relationships
between requirements
Symbol Definition
X
3.1
Concept
The requirement (row header) is conflicted by another
requirement (column header).
as rows and columns of Matrix 1. Information about their risk level
is added at the bottom of the matrix. Then, we choose each requirement from the rows and go through all the requirements, listed in
the columns, and analyze if there are any conflicts between them.
Identified conflicts are recorded in the matrix using "X" symbol.
At the end of conflict analysis, the total number of conflicts of
each requirement is recorded at the bottom of the matrix. The final
step is to revise the results and decide which requirements to include
for implementation, depending on their risk levels and number of
AVES – Automated Vehicle Safety and Security Analysis Framework
Conference’17, July 2017, Washington, DC, USA
Matrix 1
S&CS Requirements
Matrix 2
S&CS Requirements
S&CS Measures
Matrix 3
S&CS Requirements
S&CS Measures
Matrix 4
Legend:
S&CS Measures
S&CS Measures
Components
Input
Feedback
Figure 3: Correlation between Matrices 1-4.
Measures
Matrix 1
Measures
Components
S&CS Requirements
S&CS Requirements
Requirements
Requirements
Matrix 2
X
Risk level
Matrix 3
Matrix 4
Number of conflicts
Selected for
implementation
Figure 4: Graphical representation of SCSD Model.
Figure 5: Matrix 1.
Table 3: Description of the additional rows of Matrix 1
Row
Description
Risk level
Each cell must contain a symbol that represents
the risk level of the corresponding requirement.
Each cell must contain a number that shows
how many łXž the corresponding column (in
Matrix 1) has.
The cell must be marked with a tick if the corresponding requirement is judged to be selected
for implementation. Its corresponding Risk level
and Number of conflicts are used as judging criteria.
Number of
conflicts
Selected for
implementation
conflicts with other requirements. The requirements, selected for
implementation, should have no or minimum/acceptable number
of conflicts with other requirements. Otherwise, it is necessary to
revise the requirements and then repeat their conflict analysis.
It might be difficult to identify conflicts among high level safety
and security requirements in the concept phase. In such cases, Matrix 1 is still a useful tool for making the selection of requirements
for implementation based on their risk level. However, Matrix 1
is particularly useful in product development phase for analysing
conflicts between technical safety and cybersecurity requirements,
which include technical details.
3.2
Matrix 2
Matrix 2 is constructed in AVES Stages 3 and 6 to help in selecting
safety and security measures. The requirements, selected for implementation from Matrix 1, and the S&CS measures are to be row
headers and column headers of Matrix 2, respectively, as shown
in Fig. 6. This matrix is intended to capture the relationships that
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Sabaliauskaite, et al.
Table 6: Description of the additional columns of Matrix 2
M
H
Pass
L
Risk level
Selected
S&CS Requirements
S&CS Measures
Column
Description
Risk level
Each cell must contain a symbol that represents
the risk level of its corresponding requirement.
The cell must be marked with a tick, if its corresponding requirement is judged to be adequately satisfied. The judging criteria are: i)
the effectiveness of measures (which have been
selected for implementation) in satisfying the
corresponding requirement; ii) the corresponding risk level.
Note that this column, once filled, is intended
to allow the analysts to quickly spot which requirements are not yet adequately satisfied by
the selected set of measures. If the number of
unsatisfied requirements is significant, then the
selected set of measures should be revised and
this column be updated accordingly.
Pass
Type of measure
Cost
Coverage
Selected for
implementation
Figure 6: Matrix 2.
Table 4: Symbols used in Matrix 2 to denote the relationships
between requirements and measures
Symbol Definition
L
M
H
The measure is 1-30% effective in satisfying the
requirement.
The measure is 31-60% effective in satisfying
the requirement.
The measure is 61-100% effective in satisfying
the requirement.
Table 5: Description of the additional rows of Matrix 2
Row
Description
Type
of
measure
Each cell may contain up to three symbols,
namely łPž, łDž and łCž, which signify that the
corresponding measure is preventive, detective
and corrective respectively.
Each cell must contain a number that shows
the cost required for implementing the corresponding measure.
Each cell must contain a number that shows
how many łHž the corresponding column (in
Matrix 2) has.
The cell must be marked with a tick, if its corresponding measure is judged to be selected
for implementation. Its corresponding Type of
measure, Cost and Coverage are used as judging
criteria.
Cost
Coverage
Selected for
implementation
exist between requirements and measures, using symbols shown
in Table 4. The additional rows and columns appended to Matrix 2,
as depicted in Fig. 6, are described in Tables 5 and 6 respectively.
Matrix 2 is used to make a decision regarding S&CS requirement
satisfaction using the S&CS measures. If a requirement can be satisfied by the measure (shown by column headers), then at their
corresponding cell (i.e. intersection of corresponding row and column) of Matrix 2, its degree of satisfaction must be indicated. The
degree of satisfaction shows how effective the measure is in mitigating specific failures or attacks addressed by the S&CS requirements.
For more details, see Table 4.
Once the analysis of all the requirements is finished, it is necessary to determine which measures should be selected for implementation, based on several criteria, such as cost of the measure
and coverage. Once the selection of the measures is completed,
we fill in the "Pass" column; this column is intended to conclude
the requirements satisfaction analysis. Ideally, all the requirement
should have a tick in the "Pass" column. If that is not possible, at
least the requirements with high risk level should be satisfied.
3.3
Matrix 3
Matrix 3 is constructed after Matrix 2 is completed in AVES Stages 3
and 6. It is useful for analyzing relationships between safety and security measures. The S&CS measures, selected for implementation
(acquired from Matrix 2), are to be both row headers and column
headers of Matrix 3, as shown in Fig. 7. This matrix serves to capture the relationships that exist between measures, using symbols
shown in Table 7. The additional rows appended to Matrix 3, as
depicted in Fig. 7, are described in Tables 8.
In Matrix 3, if a measure complements (or conflicts) another
measure, then notation "O" (or "X") is placed at their corresponding
cell (i.e. intersection of corresponding row and column), as defined
in Table 7.
At the end of relationship analysis, the total number of supports
and conflicts for each measure are recorded at the bottom of the
matrix. If there are any conflicts, they have to be analysed and
solved by returning to Matrix 2 and modifying the list of selected
measures, and then repeating relationship analysis using Matrix 3.
AVES – Automated Vehicle Safety and Security Analysis Framework
Conference’17, July 2017, Washington, DC, USA
Pass
X
Implementation status
O
Other means
X
Implementation priority
Components
Selected
S&CS Measures
Selected
S&CS Measures
Selected
S&CS Measures
Notes
Number of supports
Figure 8: Matrix 4.
Number of conflicts
Implementation priority
Pass
Table 9: Symbols used in Matrix 4 to denote the relationships
between measures and components
Figure 7: Matrix 3.
Symbol Definition
X
The component is required for implementing
the measure.
Table 7: Symbols used in Matrix 3 to denote the relationships
between measures
Table 10: Description of the additional row of Matrix 4
Symbol Definition
X
O
The measure (row header) is conflicted by another measure (column header).
The measure (row header) is supported by another measure (column header).
Table 8: Description of the additional rows of Matrix 3
Row
Description
Number of
supports
Number of
conflicts
Implementation priority
Each cell must show the number of łOž Matrix
column (in Matrix 3) contains.
Each cell must show the number of łXž its corresponding column (in Matrix 3) contains.
Each cell must contain a number that signifies
the degree of priority of the corresponding measure. For example, 1 means highest priority; the
greater the number, the lower the priority. The
degree of priority is determined according to
the risk levels of the requirements that can be
satisfied by the corresponding measure.
The cell must be marked with a tick, if the corresponding measure is judged to be acceptable.
The judging criteria are: i) the balance between
corresponding Number of supports and Number
of conflicts; ii) the corresponding priority.
Pass
The number of supports ("O") in Matrix 3 shows the overlaps among
measures. It could help identify redundant measures. The analysis
is concluded using "Pass" row (see Tables 8 for more details).
Row
Description
Notes
Each cell may include properties of the corresponding component, which are deemed worth
mentioning ś e.g. constraints and limitations.
3.4
Matrix 4
Matrix 4 is aimed at recording and tracking the implementation
status of safety and security measures, selected for implementation
in Matrix 3. Matrix 4 is constructed in AVES Stages 3 and 6. While
construction of Matrix 4 may be skipped in AVES Stage 3 if implementation details are unavailable, it must be performed in AVES
Stage 6 so that the SCSD Model could be built in Stage 7.
The S&CS measures (acquired from Matrix 3) and the ADS components (such as hardware and software) are to be row headers
and column headers of Matrix 4 respectively, as shown in Fig. 8.
This matrix serves to capture the relationships that exist between
measures and components, using symbols shown in Table 9. The
additional rows and columns appended to Matrix 4, as depicted in
Fig. 8, are described in Tables 10 and 11 respectively.
Note that not all the measures are related to software or hardware
components. Some of them might be implemented using other
means, e.g. activities, which have to be described in łOther meansž
column of Matrix 4.
This matrix can be used when preparing for measure implementation, as well as during the implementation process. During
preparation phase, it is a useful tool for making decision on software/hardware component selection for measure implementation.
The results are recorded in "Pass" column, as described in Table 11.
During implementation phase, Matrix 4 can help to track current
status of implementing each measure. "Implementation priority"
column shows which measures should be implemented first, while
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Table 11: Description of the additional columns of Matrix 4
Column
Description
Other
Describes other means, e.g. activities, used to
means
implement measures.
Implementati- This column is the transpose of row łImplemenon priority tation priorityž of Matrix 3.
Pass
The cell must be marked with a tick if the corresponding measure has been assigned appropriate component(s) to make it viable.
Implementa- Each cell must contain a percentage value (e.g.
tion status
0-100%) that represents the progress of implementing the measure. The entire column is to
be periodically updated.
"Implementation status" indicates the progress of implementing
each measure (see Table 11 for more details).
3.5
SCSD Model
The fifth matrix is the the meta-matrix ś SCSD Model, which incorporates Matrices 1-4 into one model, as shown in Fig. 4. SCSD
Model is constructed in AVES Stage 7 at the end of AV product
development phase, using the data of Matrix 1 from AVES Stage 5,
and Matrices 2-4 from AVES Stage 6.
As mentioned in Section 2, SCSD Model is particularly useful in
production, operation, service, and decommissioning phases of AV
development lifecycle, when the detailed information from concept
and product development phases is no longer available. In these
phases, SCSD Model could be used to provide a sufficient amount
of information required for S&CS analysis.
There is a similar model, Six-Step Model (SSM), proposed in [15]
for analysis of safety and security of cyber-physical systems, by utilizing a collection of matrices to model the interrelationships among
six different dimensions of CPS ś i.e. functions, structure, failures,
safety countermeasures, attacks, and security countermeasures.
We performed a case study, in which we constructed SSM of an
AV. The findings of the case study revealed that construction of SSM
was time consuming and some of the information, captured in SSM,
was redundant. We used these findings as an input for developing
SCSD Model.
The SSM is a more complex model compared to SCSD Model;
SSM requires 6 hierarchies while SCSD Model ś 3 hierarchies; SSM
is composed of 21 relationship matrices while SCSD Model ś 4
relationship matrices. Furthermore, SSM is not tailored to fit the
AV development lifecycle.
4
SUMMARY AND CONCLUSIONS
This paper proposes a novel approach, AVES Framework, for unified,
systematic, model-based AV safety and cybersecurity analysis.
AVES Framework adheres to road vehicle development lifecycle,
and it may be used to analyze any AVs regardless of their automation
and connectivity levels. To the best of authors’ knowledge, there
are no similar approaches proposed yet.
Another novel point of this work is using principles of QFD for
safety and cybersecurity analysis, in particular, for relationship
Sabaliauskaite, et al.
analysis and decision making with respect to safety and cybersecurity requirements, safety and security measures, and system
components. Four relationship matrices and a meta-matrix, SCSD
Model, are constructed throughout the stages of AVES Framework.
This is an initial paper including an overview of AVES Framework’s stages and models. Further work will include detailed description and validation of the AVES Framework.
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Vehicle Automated Driving Systems. SAE International.
[2] 2016. SAE J3061: Cybersecurity Guidebook for Cyber-Physical Vehicle Systems.
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