论文标题
Spectrerewind：泄漏过去指示的秘密
SpectreRewind: Leaking Secrets to Past Instructions
论文作者
论文摘要
瞬态执行攻击利用Micro-Architectural Covert通道来泄漏在逻辑程序执行过程中不应访问的秘密。常用的微构造秘密渠道是那些在微体系式状态下留下持久足迹的渠道，例如，缓存状态变化，在暂时执行完成后，秘密从中恢复了秘密。 在本文中，我们提出了SpectrereWind，这是一种创建基于竞争的秘密渠道的新方法，以进行瞬态执行攻击。在我们的方法中，通过在瞬时执行受害者代码之前逻辑地发布必要的说明来建立秘密渠道。与需要同时进行多线程（SMT）的先前基于竞争的掩护通道不同，SpectrereWind支持基于单个硬件线程的掩护通道，使其在攻击者无法利用SMT的系统上可行。我们表明，可以使用商品处理器对浮点分区单位的争论来创建高性能（〜100 kb/s），低噪声掩护通道，用于瞬态执行攻击，而不是常用的flush+基于基于常用的flush+基于基于的加速cocace covert coblet频道。 我们利用所提出的秘密渠道实施了崩溃攻击，与基于现状的缓存渠道实现相比，表现出竞争性能。我们还表明，Covert频道在Chrome浏览器的JavaScript引擎中起作用。
Transient execution attacks utilize micro-architectural covert channels to leak secrets that should not have been accessible during logical program execution. Commonly used micro-architectural covert channels are those that leave lasting footprints in the microarchitectural state, for example, a cache state change, from which the secret is recovered after the transient execution is completed. In this paper, we present SpectreRewind, a new approach to create contention based covert channels for transient execution attacks. In our approach, a covert channel is established by issuing the necessary instructions logically before the transiently executed victim code. Unlike prior contention based covert channels, which require simultaneous multi-threading (SMT), SpectreRewind supports single hardware thread based covert channels, making it viable on systems where attacker cannot utilize SMT. We show that contention on the floating point division unit on commodity processors can be used to create a high-performance (~100 KB/s), low-noise covert channel for transient execution attacks instead of commonly used flush+reload based cache covert channels. We implement a Meltdown attack utilizing the proposed covert channel showing competitive performance compared to the stateof-the-art cache based covert channel implementation. We also show that the covert channel works in the JavaScript engine of a Chrome browser.
