PRISM: Lightweight Enclave Isolation with Prismatic Capabilities

2026-08-26

AI Summary

为解决TEE中内存安全和性能问题，本文提出PRISM架构，利用棱镜能力创建用户空间隔离区，实现高效的所有权建立、域转换及远程证明。

Abstract

Trusted execution environments (TEEs) protect sensitive code and data from external interference, but lack inherent memory safety. CHERI can enforce spatial memory safety at the object level. Attempts to establish a TEE using CHERI primitives suffer from (1) expensive capability revocation operations, (2) need to rely on the host operating system (OS) to support provenance tracking and physical memory protection, (3) expensive domain transitions, and (4) lack of support for remote attestation. We introduce prismatic capabilities and present PRISM, a TEE architecture for CHERI leveraging prismatic capabilities to create userspace enclaves while addressing these challenges. PRISM binds enclave 'hues' (identifiers) in prismatic capabilities to physical memory access controls, enables O(1) ownership establishment without memory sweeps, and supports efficient domain transitions that atomically activate and deactivate prismatic capabilities. Additionally, PRISM enables remote attestation of its enclaves. We demonstrate that execution of userspace enclaves in PRISM incurs only moderate overhead (<= 15%), a significant improvement over the same workloads under Intel SGX

Problem

• Trusted Execution Environments
• Memory Safety
• Capability Revocation
• Domain Transitions
• Remote Attestation

Innovation

• prismatic capabilities
• userspace enclaves
• remote attestation
• domain transitions