EN 17927:2023
(Main)Security Evaluation Standard for IoT Platforms (SESIP). An effective methodology for applying cybersecurity assessment and re-use for connected products.
Security Evaluation Standard for IoT Platforms (SESIP). An effective methodology for applying cybersecurity assessment and re-use for connected products.
This document describes a cybersecurity evaluation methodology, named SESIP, for components of connected ICT products. Security claims in SESIP are made based on the security services offered by those components. Components can be in hardware and software. SESIP aims to support comparability between and reuse of independent security evaluations. SESIP provides a common set of requirements for the security functionality of components which apply to the foundational components of devices that are not application specific. The methodology describes the re-use of evaluation results.
Sicherheitsbewertungsstandard für IoT Plattformen (SESIP) - Ein effektives Verfahren zur Anwendung der Cybersicherheitsbewertung und Wiederverwendung für vernetzte Produkte
Dieses Dokument legt ein Verfahren zur Evaluierung der Cybersicherheit namens SESIP für Plattformen und Plattformteile von vernetzten IoT Produkten fest. Sicherheitsansprüche in SESIP werden auf der Grundlage der von diesen Plattformen angebotenen Sicherheitsdienste gestellt. Plattformteile können aus Hardware und Software bestehen. SESIP zielt darauf ab, die Vergleichbarkeit zwischen unabhängigen Sicherheits-evaluierungen und deren Wiederverwendung zu unterstützen. SESIP bietet eine Reihe gemeinsamer Anforderungen für die Sicherheitsfunktionalität von Plattformteilen, die auf die grundlegenden Plattformen von nicht anwendungsspezifischen Geräten Anwendung finden. Dieses Verfahren legt die Wiederverwendung von Evaluierungsergebnissen fest.
Norme d'évaluation de la sécurité pour les plates-formes IoT (SESIP) - Une méthodologie efficace pour appliquer et réutiliser des évaluations de la cybersécurité de produits connectés
Le présent document décrit une méthodologie d'évaluation de la cybersécurité, appelée SESIP, pour les plates-formes et les parties de plate-forme des produits connectés IoT. Les déclarations de sécurité de la SESIP sont fondées sur les services de sécurité offerts par ces plates-formes. Les parties de plate-forme peuvent être matérielles ou logicielles. La SESIP vise à favoriser la comparabilité et la réutilisation des évaluations de sécurité indépendantes. La SESIP fournit un ensemble commun d'exigences relatives à la fonctionnalité de sécurité des parties de plate-forme qui s'appliquent aux plates-formes de base des dispositifs qui ne sont pas spécifiques à une application. La méthodologie décrit la réutilisation des résultats d'évaluation.
Standard ocenjevanja varnosti za platforme IoT (SESIP) - Učinkovita metodologija za uporabo ocene kibernetske varnosti in ponovno uporabo za povezane izdelke
Ta dokument opisuje metodologijo ocenjevanja kibernetske varnosti (Standard ocenjevanja varnosti za platforme IoT – SESIP) za sestavne dele povezanih izdelkov IKT. Varnostne zahteve v standardu ocenjevanja varnosti za platforme IoT temeljijo na varnostnih storitvah, ki jih ponujajo ti sestavni deli. Sestavni deli so lahko strojna ali programska oprema. Standard ocenjevanja varnosti za platforme IoT podpira primerljivost med neodvisnimi ocenami varnosti in njihovo ponovno uporabo. Standard ocenjevanja varnosti za platforme IoT določa skupen niz zahtev za varnostno delovanje sestavnih delov, ki se uporabljajo za temeljne sestavne dele naprav, ki niso aplikacijsko specifične. Metodologija opisuje ponovno uporabo rezultatov ocene.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-april-2024
Standard ocenjevanja varnosti za platforme IoT (SESIP) - Učinkovita metodologija
za uporabo ocene kibernetske varnosti in ponovno uporabo za povezane izdelke
Security Evaluation Standard for IoT Platforms (SESIP) - An effective methodology for
applying cybersecurity assessment and re-use for connected products
Sicherheitsbewertungsstandard für IoT-Plattformen - Eine effektive Methode zur
Anwendung der Cybersicherheitsbewertung und Wiederverwendung für vernetzte
Produkte
Norme d'évaluation de la sécurité pour les plates-formes IoT (SESIP) - Une
méthodologie efficace pour appliquer l'évaluation de la cybersécurité et la réutilisation
des produits connectés
Ta slovenski standard je istoveten z: EN 17927:2023
ICS:
35.030 Informacijska varnost IT Security
35.240.95 Spletne uporabniške rešitve Internet applications
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN 17927
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2023
ICS 35.030; 35.240.95
English version
Security Evaluation Standard for IoT Platforms (SESIP).
An effective methodology for applying cybersecurity
assessment and re-use for connected products.
Norme d'évaluation de la sécurité pour les plates- Sicherheitsbewertungsstandard für IoT-Plattformen -
formes IoT (SESIP) - Une méthodologie efficace pour Eine effektive Methode zur Anwendung der
appliquer et réutiliser des évaluations de la Cybersicherheitsbewertung und Wiederverwendung
cybersécurité de produits connectés für vernetzte Produkte
This European Standard was approved by CEN on 13 April 2023.
CEN and CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for
giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical
references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to
any CEN and CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN and CENELEC member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.
CEN and CENELEC members are the national standards bodies and national electrotechnical committees of Austria, Belgium,
Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia,
Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and United Kingdom.
CEN-CENELEC Management Centre:
Rue de la Science 23, B-1040 Brussels
© 2023 CEN/CENELEC All rights of exploitation in any form and by any means
Ref. No. EN 17927:2023 E
reserved worldwide for CEN national Members and for
CENELEC Members.
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms, definitions, symbols and abbreviated terms . 5
4 Overview . 6
5 Security Functional Requirements (SFRs) . 19
6 Security Process Packages (SPPs) . 38
7 Security Assurance Requirements (SARs) . 40
8 SESIP Assurance Levels . 53
Annex A (informative) SESIP evaluation case example . 60
Annex B (informative) Guidance — Attack potential rating . 61
Annex C (informative) Example use cases . 64
Annex D (informative) Security Target template . 73
Annex E (Normative) Composition Guidelines . 92
Annex F (Informative) SESIP in overall product securing process . 98
Bibliography . 101
European foreword
This document (EN 17927:2023) has been prepared by Technical Committee CEN/JTC 13 “Cybersecurity
and Data Protection”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2024, and conflicting national standards shall be
withdrawn at the latest by May 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
Introduction
This document specifies the Security Evaluation for Secure IoT Platforms (SESIP). It includes general
requirements for Security Functional Requirements (SFRs), Security Process Packages (SPPs) and
Security Assurance Requirements (SARs) designed to be used in the evaluation and certification of IoT
platforms.
SESIP is a methodology for the security evaluation of platforms on which connected products are based.
The term “platform” in SESIP is defined as the implementation of underlying features for an application
layer; a platform can be subdivided in “platform parts”.
SESIP does not address the final connected product itself, but the results of the SESIP evaluation of
connected platforms are meant to be able to be used as evidence for compliance demonstration to
standards addressing Connected Products.
This makes SESIP not redundant with current IoT standards but a tool on which those standards can base
on by reusing outputs. It is indeed impossible for a product vendor to provide, with reasonable effort,
assessment evidences for all platform parts integrated from different developers/manufacturers.
This SESIP methodology specific goals are summarized below:
• To be accessible to applicable IoT products stakeholders;
• To provide clear but harmonized security claims;
• To consider time-to-market needs by providing an optimized and efficient methodology;
• To enable the reuse of evaluation results in different products and/or between different standards
and avoid redundant evaluations of same platform (parts)without added value;
• To support Connected Products compliance demonstration to Connected Product standards.
Fulfilling of these goals allows SESIP raising the overall security in IoT ecosystems by increasing the
number of security evaluations through clarity in security claims and optimized efforts.
1 Scope
This document specifies a cybersecurity evaluation methodology, named SESIP, for platforms and
platform parts of connected IoT products. Security claims in SESIP are made based on the security
services offered by those platforms. Platform parts can be in hardware and software. SESIP aims to
support comparability between and reuse of independent security evaluations. SESIP provides a common
set of requirements for the security functionality of platform parts which apply to the foundational
platforms of devices that are not application specific. The methodology specifies the re-use of evaluation
results.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 17000:2020, Conformity assessment — Vocabulary and general principles
ISO/IEC 17065:2012, Conformity assessment — Requirements for bodies certifying products, processes and
services
3 Terms, definitions, symbols and abbreviated terms
For the purposes of this document, the terms and definitions given in ISO/IEC 17000:2020,
ISO/IEC 17065:2012 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
composite platform
platform integrating a certified platform (part)
3.2
connected application
application
overall software layer implementing an IoT end-user use case based on the underlying connected
platform
3.3
connected application part
application part
subset of the connected application defined by a specific context (e.g. data, resources, etc.) and to be
isolated from the rest of the application
3.4
connected platform
platform
hardware and/or software that provides secure services to a connected application
3.5
connected platform developer
platform developer
developers who build platform (parts) and supply them to product vendors or to other platform
developers, and who need to certify the security of the platform (parts) that they build.
3.6
connected platform part
platform part
part
hardware and/or software that implements a subset of the features of a connected platform, and that can
be evaluated separately e.g. the hardware, a cryptographic library, an OS.
3.7
connected product
product
combination of a connected platform and a connected application that a product vendor puts on the
market.
3.8
keystore
repository in which certificates, private keys, or secrets can be stored.
3.9
SESIP profile
security profile generic to a type of platform (part), template for a SESIP Security Target of a platform of
type targeted by the profile
3.10
SESIP Security Target
SESIP ST
ST
statement of SESIP security requirements in terms of security features (SFRs and SPPs) and evaluation
activities (SARs) to be addressed during the evaluation of a platform (part)
4 Overview
4.1 General
This clause provides an overview of the essential principles underlying SESIP:
• The base concepts of the methodology
• A threat model adapted to the IoT ecosystem
• A life cycle adapted to connected products in the IoT ecosystem
• Reusability, an essential objective of SESIP, in order to handle at an acceptable cost the increasing
complexity of the connected platforms that need to be evaluated in the IoT ecosystem
• Accessibility, which is required to encourage product vendors to leverage security features included
in evaluated connected platforms; the results of an evaluation is expected to be accessible and
exploitable by security-proficient developers without the need to be evaluation specialists.
• Security self-assessment in SESIP
4.2 SESIP concepts
SESIP is originated from the ISO 15408 series ([4], [5], [6]), specialized for the evaluation of connected
platforms in the context of IoT; it provides the base concepts as follows:
• SESIP keeps the main definitions and high-level concepts introduced in ISO 15408-1 [4].
• SESIP Security Functional Requirements (SFRs) for the security features to be implemented by
platforms (parts) and to be evaluated; SESIP does not use the SFR catalogue specified in ISO 15408-2
[5] but keeps the concept of a catalogue of SFRs, specialized for the IoT ecosystem, but each SFR being
at a level of final service to the user.
• SESIP Secure Process Packages (SPPs) for the security processes to be implemented by the developer
of the platform under evaluation.
• SESIP Security Assurance Requirements (SARs) for the evaluation activities to be performed; SESIP
keeps the categorization of the Security Assurance Requirements and the associated type of
developer’s inputs as in ISO 15408-3 [6], however it specifies again the content as described in 7.1.
• SESIP assurance levels; SESIP does not use “EAL” packages specified in ISO 15408-3 [6], but defines
its own assurance packages adapted to the IoT ecosystem: the SESIP levels (see Clause 8).
See details about SESIP implementation of those concepts in Clauses 5 to 8.
SESIP is an evaluation methodology that specifies as precisely as possible how to evaluate the security of
a product, in this case a connected platform. Similarly, SESIP does not specify any particular procedure,
nor does it explicitly organize the mutual recognition principles between certificates, and only provides
guidance and directions. A SESIP evaluation/certification scheme based on this SESIP evaluation
methodology is expected to be specified in another document by the certification scheme owner.
4.3 IoT use cases and threat model
4.3.1 General
IoT is a broad term, but always contains a product (“thing”) and some form of connectivity (“internet”).
SESIP focuses on the “thing” side of IoT, and on the security of connected platforms, on which connected
products are based.
4.3.2 Architecture
A connected platform typically includes the following components:
• Hardware (processing unit, memory, possibly a secure element, at least one network interface,
possibly some sensors) and associated features e.g. Firmware, Boot Loader and Root-of-Trust.
o It is assumed that the connected platform includes at least one network interface that is directly or
indirectly connected to a network and exposed to potential attackers.
• An operating system, providing a foundation to run Connected Applications on the hardware.
• A network connectivity layer (e.g. Comm library), allowing the connection of the product to backend
or other products.
• Software application services offered to connected applications, providing an application framework
to product vendors (e.g. Crypto library, Secure Storage, Identity and Attestation features).
The Figure 4-1 shows an example of a Connected platform:
Figure 4-1 — Example of connected product architecture
4.3.3 Assets
Platform assets depend on the platform implementation and use case. However, the list of typical main
assets shown in Table 4-1 has been established by a group of IoT stakeholders:
Table 4–1 — Main assets of connected platform
Asset Protections
User data (local) Privacy concerns are essential.
Protections of confidentiality, integrity and authenticity shall be
provided.
User data (authentication data) Confidentiality is required for secrets.
Secondary data (like counters) shall be appropriately protected
(confidentiality, integrity).
Data in transit (internet) Confidentiality and integrity are often essential, as is the
authenticity.
Data in transit (local) Integrity is often essential.
Confidentiality is not a systematic requirement.
Authenticity is less common.
Code, including platform code and Integrity and authenticity are strong requirements.
application code
Confidentiality is optional.
Product identity Integrity and unicity are required.
Configuration and system data Integrity and authenticity are required.
Life cycle related data Integrity is required.
It is understood that not all platforms provide complete coverage, but such limitations shall be carefully
motivated when claiming SESIP SFRs (e.g. limited bandwidth or legacy protocol).
The assets may be further categorized into different criticality levels that will be protected at the
appropriate level in the platform (part) – in the case of a multi-assurance platform, see 4.5.2. For instance,
there may be different levels of cryptographic keys, depending on their function and life cycle. In that
case:
• Protection mechanisms shall be appropriate at every level.
• Assets shall be usable without disclosing them to a lower level.
• Usage of the assets from a lower level shall be appropriately controlled (access control).
4.3.4 Attackers and threats
4.3.4.1 Base scenario
The minimum and mandatory threat model in SESIP is an attacker with only remote (no physical) access
to the connected platform during the exploitation phase (see Annex B). This addresses the main IoT
concern of a scalable attack exploited using a remote connection to the connected platform.
Nevertheless, the attacker can perform any type of preliminary attack on a connected platform (part)
owned, including physical attacks; this shall be considered for the base scenario in an identification phase
(see Annex B).
Also, in this base scenario, threats related to untrusted software that could be loaded onto connected
platforms are not considered.
4.3.4.2 Extended scenario – physical access
When connected platforms are physically accessible to attackers, the threat model can be expanded and
covered by the use of the SFRs “Limited physical attacker resistance” and “Physical attacker resistance”.
The typical example scenarios where attackers have physical access to a victim product are:
• Connected platform deployed outside of a physically protected environment; e.g. a doorbell, outside
IP camera.
• Temporary physical access; e.g. “evil maid” attacks where the attacker has temporary physical access
to the product that has already been acquired by an end user, or “supply chain” attacks where the
attacker delivers a compromised product to the target.
4.3.4.3 Extended scenario – untrusted software
When untrusted software can be loaded onto connected platforms, either by the end user or by an
external entity, and that could impact the platform, its parts, or its applications, the base threat model can
be expanded and covered by the use of the SFRs “Software attacker resistance: Isolation of platform”,
“Software attacker resistance: Isolation of platform parts”, and “Software attacker resistance: Isolation of
application parts”.
4.4 Connected product life cycle
Different life cycle models can be applied to connected products, and to the connected platforms that
compose each product. Nevertheless, some patterns can be found in most products that are significant
for security:
Vendor provisioning is the phase during which the product is provisioned with credentials that are
shared with the vendor’s backend, and that allow the product to communicate securely with the backend
and to perform management operations. This phase typically concludes with the delivery of the product
to the customer.
User provisioning is the phase during which the product is provisioned with a user’s credentials and
specific data that allow the product to represent that user. This phase typically concludes with the normal
usage phase of the product.
Normal usage is supposed to be the product’s normal state, until one of the following events occurs:
• The user applies a factory reset, which removes all user-related data and credentials, and prepares
the product to be transferred to another entity (e.g. for resale, for return, or even for temporary
storage). The product is then ready again for user provisioning, but a user should not have the ability
to return the product to an earlier life cycle phase.
• The user decommissions the product, before discarding it. This Terminated state is irreversible.
Some products may include an additional state related to Field return, during which specific debugging
features may be available. All user data and credentials shall have been removed before reaching that
state.
The product life cycle shown in Figure 4-2 is used as a reference in the SFRs when references to a life
cycle are required.
Figure 4-2 — Reference product life cycle
Note that the vendor states are only reachable by the vendor, either before delivery of the product, or
after return of the product by the user.
In addition to the product life cycle, the connected platform and some of its parts may have different life
cycles that are also significant to security. Such security life cycles are product-specific, and their
contribution to the security of the connected platform (part) should be described in the corresponding
Security Target.
4.5 Reusability in SESIP
4.5.1 General
Connected products are complex, often much more than most of the products that have had their security
formally certified until today. SESIP recognizes this by providing a dedicated methodology for the
connected platforms on which these products are based. Connected platforms are often built by
assembling several pre-existing hardware and software components; some of them include security
components that protect critical assets and need to be evaluated at a high assurance level. Such
components are often integrated in several connected platforms targeting different use cases.
SESIP methodology specifies ways to independently evaluate subsets of components, which may then be
called platform parts, and reuse the evaluation results in any connected platform. Those results can come
from an evaluation under SESIP methodology, but also from other compatible external evaluations.
4.5.2 Building connected products from connected platforms
4.5.2.1 Reuse of external evaluations
As mentioned in 4.3, SESIP focuses on the “Things” in IoT, and more specifically on the solutions on which
these connected things are built, which we call connected products. Every connected product belongs to
a category or a vertical, and dedicated security standards are likely to be built for the most common types
of connected products (e.g. Consumer IoT, Industrial IoT, Connected Vehicles, etc.). For each type, a
specific risk analysis is needed to determine the appropriate functional and assurance requirements and
may then result in the creation of a specific evaluation scheme.
In such a multi-scheme context, the SESIP methodology security requirements are specified in a way that
enables the establishment of equivalence with the requirements of other schemes. After successful
compatibility analysis, this allows the reuse of evaluation results between schemes.
4.5.2.2 Reuse of platform parts evaluations
4.5.2.2.1 General
A typical connected platform is not a single component, as it comprises some hardware, including at least
one [micro]controller or [micro]processor, and some software, including at least an operating system. A
connected platform may include many more components, for instance related to communication or
security. A vendor typically builds its connected platform by selecting hardware and software
components, most likely from different third-party vendors, and then assembling them.
Every vendor in that supply chain needs to provide security evaluation assessment, ending with the
integrator in charge of ensuring that the fully connected platform is secure. To maintain security through
the whole assembly process can be quite complex, unless all the vendors of those components (hardware
and software) use a common methodology.
In order to address this, SESIP considers the following reuse contexts:
• Reuse of evaluated platform parts in several platforms (parts)
• Reuse of evaluated platform parts from a hosting platform (part) to another one
4.5.2.2.2 Reuse of evaluated platform parts in several platforms (parts)
SESIP allows the evaluation of platform parts, individually or in composition (see 4.5.3), in such a way
that the evaluation results of those platform parts remain applicable in different connected products.
An example is provided in Figure 4-3:
Key
Assurance claim
Evaluation scope
Reused into
Figure 4-3 — Example of evaluation results reuse in several platforms (parts)
4.5.2.2.3 Reuse of evaluated platform parts from a hosting platform (part) to another one
SESIP allows for the reuse of evaluation results for parts evaluated inside a particular platform to be
integrated into another platform (part).
An example is provided in Figure 4-4:
Key
Assurance claim
Evaluation scope
Reused into
Figure 4-4 — Example of evaluation results reuse from a platform (part) to another one
In all cases, the reuse of evaluation evidence is in particular based on security integration guidance for
each component; then, the assessment of the connected platforms integrating evaluated platform parts
requires the verification that secure integration guidelines and composition rules (see 4.5.2) are
respected.
Note that reuse effort will vary depending on the use case, from straightforward portability with few
verifications, e.g. full self-containment of security functionality, to a dedicated set of activities needing to
be performed on the integrating scope and to be defined in the previously mentioned integration and
composition guidelines. In any case, the effort will be significantly lower than a re-evaluation on
evaluated parts in a new platform (part).
Using SESIP as core methodology allows vendors to have a clear understanding of the assumptions and
guidance of the third-party components they integrate by reusing evidence provided by the components’
vendors during the evaluation of their platform (part).
4.5.2.3 Reuse of platform evaluation in connected products
Most Connected Products will be built by vendors who develop one or several dedicated Application(s)
on top of a generic or off-the-shelf connected platform. SESIP focuses on the connected platform to
provide a foundation for the security assessment, and potentially the certification, of Connected Products.
It addresses the security level of the whole operating system including services used for the storage,
installation, initialization, and execution of this Application, as well as its data protection.
4.5.3 Additive composition within SESIP
4.5.3.1 General
The objective of additive composition is to facilitate the evaluation of a connected platform by reusing
previous evaluation results of the platform (parts).
SESIP allows different composition scenarios:
• Combination of previously evaluated platform parts
• Combination of platform part(s) to be evaluated with previously evaluated platform part(s)
• Combination of a platform to be evaluated with previously evaluated platform parts
Additive composition allows successive compositions of platform parts into wider ones which themselves
can be evaluated and integrated into wider platform parts, as illustrated in Figure 4-5. Each composition
benefits from the reuse of the evaluation results of the previously integrated platform part. Such
integrations and related composition evaluation can be done until reaching a full IoT platform, ready to
be part of an IoT device. The final IoT device can rely on the successive evaluated platform parts and
reuse each evaluation result. All the supply chain actors benefit from the additive composition: from the
evaluation of a hardware block, through the evaluation of intermediate modules, to an evaluated device.
An example of composition scenario is shown in Figure 4-5:
Individual evaluations
Any set of components aiming at being integrated
into a Connected Platform can be individually
evaluated
Composition 1
Each target previously individually evaluated can
become a part of a composition
Composition 2
Composition 1 can then be combined with an upper
layer not yet evaluated. It becomes a part of this new
composition
Key
Assurance claim
Platform/part
Figure 4-5 — Example of composition scenarios
4.5.3.2 Composition evaluation rules
Evaluation of a platform part to be further integrated into a wider platform (part) shall produce
composition guidelines listing rules to be respected by any other platform part interacting with it. This
shall be specified as an objective for the environment and referred to specifically in the guidance as per
SESIP ASE and AGD requirements (see details in 7.2).
Evaluation of a composition of platform parts shall assess that the guidance (including objectives for the
environment, user guidance, integration guidance, etc.) of each platform part is respected.
Evaluation of a composition of platform parts shall assess the impact of the composition on the correct
security functioning of the platform parts.
Annex E outlines the steps of a composition process and provides detailed guidelines for each actor.
4.5.3.3 Assurance level of compositions
Composition may occur between platform parts that are evaluated at different assurance levels. By
default, the composition can claim at most the lowest assurance level of the platform parts it is composed
of. For instance, a connected platform composed of a SESIP2 platform part and a SESIP5 platform part
cannot be certified at an overall level higher than SESIP2 without providing additional evidence about
the SESIP2 part or about its usage by the SESIP5 platform part.
Nevertheless, in such a case, the Security Target may identify a subset of the SFRs that require higher
assurance. In that case, the Security Target can claim the assurance level of the high-assurance part,
provided that the SFRs covered by the higher part are clearly identified to the reader. Using the example
from the previous paragraph, the connected platform could claim being at SESIP2 with a SESIP5 part
covering only the SFRs of the SESIP5 part. The assurance level for such an evaluation shall be referred to
as “SESIP2 with SESIP5 part(s)”.
Moreover, the SESIP level of an individual platform part could also be increased once composed with
another platform part providing security features with a higher assurance level; this shall be
demonstrated by evidences at the composition level.
Such multi-assurance evaluations are expected to fulfil industry requirements for composition. For
instance, industry requirements may mandate that critical assets such as some cryptographic keys or
credentials be specifically protected using a tamper-resistant product like a secure element, while other
assets that are less critical will require a lower level of protection. In that case, the connected platform is
required to have a subset evaluated to a higher assurance level, as specified above.
4.6 Accessibility and transparency
IoT security remains a challenge. A SESIP evaluation will help IoT vendors to select connected platforms
that provide an appropriate level of security, but SESIP also aims to ensure that these vendors have the
ability to properly leverage in their products the security features provided by evaluated platforms
(parts). This is achieved mostly through the Security Target, which is expected to become a document
exploitable by developers who are proficient in security but are not evaluation specialists. This can be
achieved by ensuring that Security Targets are transparent and readable, that the security choices are
explicit and motivated, and that SESIP can ensure some consistency between Security Targets.
To that end, SESIP Security Targets shall respect several key characteristics:
• The security objectives are the concretization of the risk analysis informing the reader about the
security features to be covered by the product. They shall be specified in the Security Target writer
such that developers can leverage these features, and to facilitate the reuse of SESIP evidence.
• The SESIP Security Functional Requirements (SFRs), which are the expression of the security
objectives into implementation requirements, are tailored for connected platforms. In SESIP, each
SFR covers a full security purpose by itself. This allows the Security Target users to develop an
intuitive understanding of the security requirements. Note that flexibility for requirement
construction is lower than when purposes are met by several SFRs; however, in a specific context
where needs are predictable, such as a connected platform, such flexibility has been found not
beneficial. SESIP specifies a set of such SFRs, which are detailed in Clause 5.
• The specification summary written by the platform evaluator shall be at a sufficient level of detail to
demonstrate that the SFRs are met by the specific implementation.
• The summary description of the flaw remediation process, written by the platform (part) developer,
shall explain in particular how the discovery of a vulnerability and the subsequent analysis may lead
to the development and distribution of a platform update or to other corrective measures.
• Reference to user guidance shall be included, along with a description of how a prospective user can
access this documentation.
Note that accessibility does not necessarily imply oversimplification; in particular, the semantics of SESIP
SFRs are precisely specified, so there is no ambiguity about the meaning of the SFR, even expressed in
plain language.
The SESIP Security Target and the documentation that it refers to are intended to be accessible
documentation, at least to prospective adopters of the platform (part); this can be refined in individual
schemes, depending on the security sensitivity of the evaluated platforms (parts).
4.7 Security self-assessment in SESIP
Security self-assessment is achievable with SESIP, but as self-assessment has many different meanings in
the industry, it is important to specify it here.
Security self-assessment by the developer is based on the demonstration that all security requirements
are properly covered in the form of a rationale included in the SESIP Security Target.
Such a rationale shall be provided for:
• Every Security Functional Requirement claimed, describing how this requirement is covered by the
implementation
• In the case of a composition, every security objective for the environment defined by a platform part,
to demonstrate how this objective is met and/or specify it again as a security objective for the
platform environment
• The flaw remediation claim, providing a description of a compliant process
• Each document required by the claimed Security Assurance Level, explaining how that
documentation can be accessed
• Publicly known vulnerabilities against the platform (part), providing a vulnerability review
Every rationale is based on a self-assessment by the developer that shall be validated by a third-party
platform evaluator. The extent of work performed by the platform evaluator depends on the selected
assurance level.
4.8 Catalogue of security features and assurance packages
SESIP includes catalogues of security features as an essential part of the methodology:
• The catalogue of Security Functional Requirements (SFRs) which allows for a consistent specification
of platforms (parts) and supports a fair comparison between them.
• The catalogue of Security Process Packages (SPPs) which allows the claim and the application
verification of specific secure processes to be implemented by the platform developer, at any phase
of the platform life cycle.
These catalogues specify a set of security features that are essential to platforms (parts), and for which
there is a shared understanding in the community. These security features are therefore more likely to
be accessible to product vendors; they also simplify reusability and contribute to SESIP’s formalism (see
previous subclauses).
Those sets of security features will evolve over time, following the evolution of IoT security challenges,
growing usage of the SESIP methodology, and the security responses provided by connected platforms.
Platform (part) vendors may also want to differentiate their offerings by including platform-specific or
innovative security features that bring added value to their customers, and it is possible to have such
features evaluated following the SESIP methodology.
However, it is also expected that the methodology provides the stability required to build and maintain a
coherent certification ecosystem. Therefore, in the case where a feature does not match any of the
SFRs/SPPs specified in the SESIP catalogue, a vendor may be allowed by the scheme to add product-
specific SFRs/SPPs, as long as they are explicitly identified as such, and are clearly separated from the
SFRs/SPPs already in the catalogue.
Regarding Security Assurance Requirements (SARs), vendors are not allowed to claim any additional
requirements in a SESIP evaluation. However, a specific certification scheme may include limited
refinement of the SARs in the SESIP levels.
4.9 SESIP profiles and mappings
4.9.1 General
SESIP profiles and SESIP Mappings are documents intended to support the usability of the SESIP
methodology in the field.
4.9.2 SESIP profiles
The SESIP methodology allows the specification of security profiles generic to a type of platform (part);
e.g. MCU/MPU, cryptographic library, communication library, etc. These are called SESIP profiles: a SESIP
profile document is a generic SESIP Security Target defining the SESIP requirements in terms of security
features (see Clause 5) and evaluation activities (see Clause 7) to be addressed during the evaluation of
a platform (part) of the type targeted by the profile.
SESIP profiles are intended to be written by entities or groups needing security evaluations for a specific
market and/or playing a role in such evaluations. This allows them to ensure that any platform (parts)
evaluated against a SESIP profile implements an expected minimum set of features, reaching a targeted
security level; also, as the same set of features is assessed based on the same evaluation activities, this
allows comparability between evaluations of different evaluated platform (parts).
Thanks to the accessibility of SESIP requirements (see 4.6), stakeholders without specific expertise in
evaluation are able to write and understand a SESIP profile.
Note also that profiles allow the consideration of risk and threat analysis for specific type of products;
such risk analysis would have previously been established by the relevant actors (e.g. via dedicated
working groups of industrials). See Annex F for more details.
4.9.3 SESIP mappings
As specified in 4.5.1, SESIP is intended to work with existing standards, providing them with a framework
for the evaluation of their requirements. Indeed, SESIP specifies security requirements (see Clauses 5 and
7) that can be claimed by developers to be addressed in SESIP evaluations. Those requirements have been
expressed at a level allowing the coverage of main features of IoT platforms. As a result, requirements of
existing standards can easily be mapped to SESIP requirements.
Along with such mapping, the results of the SESIP evaluation can be reused as a demonstration of
compliance to an IoT standard, confirming that the IoT standard’s security features have been correctly
and efficiently implemented.
SESIP Mappings are intended to be written by entities or groups who would like to use SESIP evaluation
results as the basis for the demonstration of compliance to a standard. The benefit of the SESIP evaluation
in this context is the reuse of an initial SESIP evaluation to demonstrate compliance with several
standards, each standard being associated with a dedicated mapping.
5 Security Functional Requirements (SFRs)
5.1 General
Connected platforms need to provide developers and evaluators of IoT applications with functionality to
build secure products and allow efficient verification of the accurate use of these secure platforms by
users, developers, and evaluators/certifiers. Such needs are expressed by Security Functional
Requirements (SFRs) which are generic security features to be implemented by connected platforms.
This clause provides a catalogue of SFRs that have been specified by a group of IoT actors based on their
own expertise and on a continuous monitoring of security requirements related to platform layers
coming from the field (e.g. through IoT standards) and for which a SESIP evaluation can produce reusable
assessment outputs.
The developers shall use this catalogue to select the SFRs to be claimed in the Security Target to specify
the security mechanisms implemented by their platform (part) and to be part of the security evaluation
scope. The text of the SFRs cannot be modified; however, they can be refined and/or specified more in
details through refinements or application notes. This is in particular useful in case of SESIP profile (see
4.9) and/or when mapping to IoT standards requirements.
This catalogue of SFRs can be extended by proprietary SFRs in Security Target and SESIP profiles when
none in the catalogue can be used to claim a specific security feature to be part of the evaluation.
The SFRs in this catalogue are specified with the wording of the requirement, the “value”, and the
“considerations”.
• The wording of the requirement specifies what shall be implemented; in some requirements, the text
includes fields within angle brackets (< > ) to be filled with the specificities of platforms (parts).
• The “value” section specifies the value added by a platform providing this functionality, to the users,
evaluators, and developers of composite IoT products and platforms.
• The “considerations” section specifies what aspects should be considered in the evaluation and
certification of this SFR.
5.2 Identification an
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