Dep-TEE: Decoupled Memory Protection for Secure and Scalable Inter-enclave Communication on RISC-V
Shangjie Pan, Xuanyao Peng, Zeyuan Man, Xiquan Zhao, Dongrong Zhang, Bicheng Yang, Dong Du, Hang Lü, Yubin Xia, Xiaowei Li · 2025
Trusted Execution Environment (TEE) has been widely implemented by modern hardware vendors to protect security and privacy-sensitive applications and data, such as Intel SGX/TDX, ARM TrustZone, AMD SEV, and RISC-V Penglai. However, existing TEE systems face challenges in balancing memory isolation among security, performance, and scalability requirements. This paper introduces a novel TEE system, Dep-TEE, which decouples memory protection (to segments) from address translation (to page tables). This design improves communication performance by dynamically adjusting memory protection capabilities, without sacrificing application compatibility, and enhances security by safeguarding against attacks on page tables. We have built a prototype of Dep-TEE based on FPGA, incorporating hardware extensions and software support. The evaluation demonstrates that Dep-TEE significantly surpasses existing TEE solutions, achieving three orders of magnitude lower communication latency and 10x greater scalability while maintaining robust security guarantees.