Platform Security Architecture

The Platform Security Architecture (PSA) is a holistic set of threat models, security analyses, hardware and firmware architecture specifications, and an open source firmware reference implementation. PSA provides a recipe, based on industry best practice, that allows security to be consistently designed in, at both a hardware and firmware level.

PSA is a contribution from Arm to the entire IoT ecosystem, from chip designers and device developers to cloud and network infrastructure providers and software vendors.

PSA is scalable for all connected devices, offering common ground rules and a more economical approach to building more secure devices.

If you’re ready to get started, access PSA resources now.

Standardized isolation

• Designed to secure low cost IoT devices, where a full Trusted Execution Environment (TEE) would not be appropriate
• PSA protects sensitive assets (keys, credentials and firmware) by separating these from the application firmware and hardware
• PSA defines a Secure Processing Environment (SPE) for this data, the code that manages it and its trusted hardware resources
• PSA is architecture agnostic and can be implemented on Cortex-M, Cortex-R and Cortex-A-based devices
• The initial focus is Cortex-M-based devices

Standardized interfaces

• PSA specifies interfaces to decouple components:
  • Enables reuse of components in other device platforms
  • Reduces integration effort
• Partners can provide alternative implementations:
  • Necessary to address different cost, footprint, regulatory or security needs
• PSA provides an architectural specification:
  • Hardware, firmware and process requirements and interfaces

Example of IoT device implementation

• OEMs can choose their preferred implementations.
• Trusted Firmware-M will be a new OSS project:
  • To reduce rework across our partners
  • To speed up device or component validation against standards such as Common Criteria EAL
• Open to any RTOS and other partners