基于TEE的主动可信TPM/TCM设计与实现

可信技术正在从被动可信度量向着下一代的主动可信监控方向发展，要求TPM/TCM模块有能力主动度量和干预主机系统，传统的TPM/TCM从架构和运行机制等方面都无法满足这种能力.TEE（trusted executionenvironment）技术提供了可信执行环境和主动访控能力，为构建下一代TPM/TCM提供了基本平台，但还存在系统结构、存储以及通信等多方面挑战.提出基于ARM平台TrustZone机制的TZTCM方案，通过分核异步系统架构解决TZTCM独立可信运行和主动可信安全监控问题，基于PUF（physical unclonable functions）安全存储机制和基于UUID（universally unique identifier）的TEE安全通信机制，解决了TEE环境下可信平台模块的存储安全和通信安全问题，为设计实现主动可信TPM/TCM给出了理论和实践参考.通过实验验证了所提关键机制的有效性，实验结果表明，TZTCM在密码计算能力上较常见TPM也有很大提升.TZTCM只需要在系统中增加或修改相应的软/固件，除了主动可信监控能力，还具有低成本、高性能、低功耗、易升级等特点，相对传统TPM/TCM具有非常明显的优势.

Design and Implementation of TPM/TCM with Active Trust Based on TEE

Trusted computing is being developed towards the next-generation active safeguard, which requires that the TPM/TCM has the ability to actively measure and intervene the host system. Unfortunately, traditional TPM/TCM can not satisfy the requirements in the respects of the architecture and the runtime mechanisms. TEE (trusted execution environment) technology provides a trusted execution environment and the ability of accessing/controlling the host resources during the run-time, which brings a foundation for the next generation TPM/TCM. However, there are still three main challenges:Software architecture, secure storage, and secure communication. In this paper, we propose the design and implementation of TZTCM, which is a TPM/TCM scheme based on ARM TrustZone. TZTCM adopts several key mechanisms to overcome the three challenges. Firstly, the NUCAA (non-uniform core assigned and asynchronous) system architecture is designed to enable the independent and active operation of TZTCM. Secondly, the secure storage mechanism based on PUF (physical unclonable functions) is designed to guarantee the privacy of data in TZTCM. Thirdly, the secure communication mechanism based on UUID (universally unique identifier) is designed to prevent the channel (between host and TZTCM) from malicious activities. Therefore, TZTCM provides a prototype system of the next-generation TPM/TCM. We show that TZTCM has the identical security as a hardware TPM/TCM chip via theoretical analysis. We implement an instance of TZTCM on an ARM development board (Hikey-board 620), and the runtime test shows that TZTCM can achieve higher performance for cipher computing than traditional TPMs. Compared to current TPMs/TCMs, TZTCM has very obvious advantages in many aspects:active safeguard capability, only software/firmware required, easy update, and low power consumption.