# On The Performance of ARM TrustZone

## TL;DR

This paper provides a detailed analysis of the performance and energy costs associated with ARM TrustZone technology and OP-TEE framework, focusing on secure storage and world switching in real and emulated environments.

## Contribution

It offers the first comprehensive empirical evaluation of TrustZone's performance and energy consumption, including secure storage and context switching costs.

## Key findings

- Quantifies energy consumption of TrustZone operations
- Measures performance impact of secure world switching
- Provides insights into TrustZone's efficiency in real hardware

## Abstract

The TrustZone technology, available in the vast majority of recent ARM processors, allows the execution of code inside a so-called secure world. It effectively provides hardware-isolated areas of the processor for sensitive data and code, i.e., a trusted execution environment (TEE). The OP-TEE framework provides a collection of toolchain, open-source libraries and secure kernel specifically geared to develop applications for TrustZone. This paper presents an in-depth performance- and energy-wise study of TrustZone using the OP-TEE framework, including secure storage and the cost of switching between secure and unsecure worlds, using emulated and hardware measurements.