SecPaging: Secure Enclave Paging with Hardware-Enforced Protection against Controlled-Channel Attacks

As a prevalent privacy-preserving technology, Trusted Execution Environment has become widely adopted in numerous commercial processors. Nonetheless, they remain susceptible to various controlled-channel attacks. Untrusted operating systems can deduce enclave secrets by manipulating page tables or observing allocation- or swap-based page faults. In this paper, we propose SecPaging, a novel secure enclave paging mechanism based on hardware-enforced and microcode-supported protection to prevent these attacks. First, enclave PTEs are protected through hardware isolation, preventing privileged attackers from malicious tampering or observations. Second, an Eager-Allocation mechanism is employed to prevent allocation-based controlled-channel attacks. Besides, a Record-Reload mechanism is proposed to prevent swap-based controlled-channel attacks. We simulate SecPaging on real SGX. Experiments demonstrate that controlled channel attacks can be defended with minimal performance overhead.