SaTC: An Architecture for Restoring Trust in Our Personal Computing Systems

今天的计算机是如此复杂和不透明，以至于用户不可能希望知道机器内发生的一切，更不用说信任了。虽然软件安全技术有助于确保用户计算的完整性，但它们仅与底层硬件一样值得信任。尽管许多建议在一定程度上缓解了硬件信任问题，但用户最终必须依赖于其他各方的保证。这项工作通过一个简单、小且速度慢的可插拔硬件元素来恢复硬件信任。这个项目研究的是提供信任核心的技术，即使是最激进的系统也不会减慢速度，并且易于制造。为了使这个缓慢但可信的硬件元素在现实系统中有用，它不能显著降低系统性能。为了实现这一目标，本工作开发了两项补充技术：执行指令的无依赖并行验证和基于密码散列的存储完整性保证。此外，加密散列还确保了代码的完整性，并防止处理器执行其自己的恶意代码。这些技术的组合提供了一个安全的硬件环境，在这种环境中，只要他们的软件也是安全的，用户就不必担心他们的数据会被泄露。因此，当与开发良好的软件安全技术相结合时，这项工作显著提高了用户对其计算系统的信任级别。

Computers today are so complex and opaque that a user cannot possibly hope to know, let alone trust, everything occurring within the machine. While software security techniques help ensure the integrity of user computations, they are only as trustworthy as the underlying hardware. Even though many proposals provide some relief to the problem of hardware trust, the user must ultimately rely on the assurances of other parties. This work restores hardware trust through a simple, small, and slow pluggable hardware element. This project investigates techniques that provides a kernel of trust that keeps even the most aggressive systems in line without slowing them down and is easy to manufacture.For this slow but trusted hardware element to be useful in real world systems, it must not degrade system performance significantly. To achieve this goal, this work develops two complimentary techniques: dependence-free parallel verification of executed instructions, and cryptographic hash-based memory integrity assurance. Additionally, cryptographic hashing also ensures code integrity and prevents the processor from executing its own malicious code. A combination of these techniques provides a secure hardware environment where users need not worry about their data being compromises, as long as their software is also secure. Therefore, when combined with well-developed software security techniques, this work provides a significant increase in the level of trust users place in their computing systems.