Taking Security-By-Design To The Next Level

Trusted, independent security testing is critical to enabling widespread deployment of IoT devices.


It’s hard to argue that the pre-eminent challenge before our industry today is security. While each sensational hacking headline gets readers’ attention, countless engineers and developers behind the scenes innovate security solutions every day to stay one step ahead of the hackers.

At a high level, companies have begun to work together toward holistic solutions to complement their own security implementations on their own products and solutions. Arm launched the Platform Security Architecture (PSA) in 2017, in which we defined a framework to bring best-practice approaches to security. Since then, a huge amount of work has been done to continue to equip the design ecosystem to offer consistent secure foundations for devices, with regular deliveries. For example, this time last year, we released the first set of PSA Threat Models and Security Analyses documentation.

But we as an industry need to keep our foot on the security gas pedal because those mischief makers never sleep. Now it’s time to combat the current lack of security validation of IoT devices. We’re doing this by partnering with renowned test lab partners Brightsight, CAICT, Riscure and UL, and security experts Prove&Run, to create PSA Certified. This program is a natural step in the evolution of PSA, since trusted, independent security testing is critical to enabling the development and deployment of these devices at scale.

Why pay attention?
PSA Certified is applicable to the vast majority of the IoT device market volume today. It is based on openly published threat models, specs and open source reference code, allowing for older MCUs, as well as newer processor architecture, processors, to be tested.

Developers who build systems in line with PSA principles will be able to have all products tested and certified at one of three assurance levels.

Level 1:  The foundation of PSA Certified
This is the initial level of certification which requires a critical security questionnaire based on PSA security model goals and IoT threat models. There are different forms depending on if you are a chip maker, OS provider or device maker, and once completed, the questionnaire is reviewed alongside a PSA Certified lab check of your product.

The foundational Level 1 certification uses the 10 security model goals from the PSA architecture documents and aims to catch common security issues through an assessment of security functions. The questionnaire can be downloaded, filled in and then you can contact a partner test lab for an interview style assessment.

We have already seen leading silicon partners and IoT platform providers achieve Level 1 certification, including Cypress, Express Logic, Microchip, Nordic Semiconductor, Nuvoton, NXP, STMicroelectronics and Silicon Labs, and are listed on psacertified.org.

Level 2: Lab-based evaluation
Level 2 is aimed at chip makers and includes a 25-day lab-based evaluation against the PSA Root of Trust (PSA-RoT) protection profile. This time-limited evaluation makes the scheme affordable and efficient, and tests for both software and light-weight hardware attacks.

PSA Developer APIs – simplifying developer access to security functions 
PSA Functional API Certification is a separate certification which uses a test suite to prove that PSA based solutions have a consistent set of APIs for essential security functions, ensuring a consistent developer experience. As we launch, Nuvoton and OS provider ZAYA have already achieved both PSA Certified Level 1 and PSA Functional API Certification, and Arm Mbed OS provides out of the box compliance with PSA Certified Level 1 and PSA Functional API Certification in its latest release.

What’s next for PSA Certified?
PSA Certified Level 3 is under development and will support more extensive attacks such as side channel and physical tamper, and we will bring it to market in the near future. There is also room for additional device level evaluation such as any vertical specific devices, and we will share more information on this later in the year.

The goal of PSA Certified is to build trust in IoT and services. The program completes the circle in delivering the total PSA IoT security framework, providing a mechanism for the whole value chain to more easily specify or buy silicon or devices with the right-level of security. As it becomes widely utilized, it will build trust in the ecosystem through independent security testing of large volumes of designs and enable the ecosystem to agree a solid security API for the industry.

Visit PSAcertified.org to find out more and discover products already certified and how you can set up your products for certification as well.

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