Security

This page is an entry point to a list of articles related to STM32 security. Security means protection from an attacker, seeking to exploit the product. If you are looking for a means to secure the functionality and mitigate failures, you should be looking for Safety.

STM32L5 security Learn how to use STM32 security and enable/disable TrustZone on STM32L5

STM32 cryptograhic library Learn how to use STM32 cryptographic library

A guide to use specific STM32 security feature How to use available security features

Security tips and use cases Tips about security implementation in different use cases

Mitigating a specific threat Basic introduction into available protections and their use

1. Concepts of security in STM32

For a long time the general purpose microcontrollers had little on no security features and secure applications relied on purpose built smartcard or secure element ICs. These are also based on a microcontroller architecture, but the two worlds were clearly separated for decades.

Proliferation of microcontrollers to various connected devices or sensitive applications gradually began to blur the borderline. A modern microcontroller usually provides a developer with means to thwart all but the very sophisticated attacks.

It’s important to establish 3 terms:

• Asset – value to be protected
• Threat – type of attack
• Vulnerability – a weakness that can be exploited

There are several reasons to try to improve security of a device – the obvious assets.

1. Protection of own intellectual property. Make it more difficult for indecent competition trying to steal your ideas.
2. Protection of user data. Some customers may care about their privacy.
3. Reliability – in some cases a DoS attack is major threat. Even worse case is a hijacked device being abused for attackers own purposes.
4. Brand image bolstered by a security certificate (or damaged by a history of successful hacks)

While there is no such thing as a perfect security, it’s important to balance the security efforts with the expected efforts the attacker could be willing to invest. Popular device with lots of assets to protect needs security countermeasures, while application with low production volume or no assets to protect may not need any.

To make informed decision (risk analysis) it’s necessary to identify the assets, threats and vulnerabilities.

A topic that stands out as a particularly important is the security of deploying patches or firmware updates securely for products that are already in the field. Secure solution called SBSFU is template for such situation.

For further reading please continue to: AN5156 Introduction to STM32 microcontrollers security