Bucketing and information flow analysis for provable timing attack mitigation
Bucketing and information flow analysis for provable timing attack mitigation
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DOI：
10.3233/jcs-191356
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发表时间：
2020-11
期刊：
影响因子：
--
通讯作者：
Tachio Terauchi;Timos Antonopoulos
中科院分区：
文献类型：
--
作者：
Tachio Terauchi;Timos Antonopoulos
本文调查了安全渠道对计时通道攻击的影响。对少数可能性的观察，几乎没有正式的分析，即在本文中有效地进行计时式攻击可以使用两个条件来确保系统免受自适应时间通道攻击的安全性。当应用水库时，该系统将满足第一个条件，因此，与定时通道攻击变得安全。 - 渠道信息泄漏，并将某些条件放在侧通道上，以确保整个系统的安全性。虽然我们实例化了我们对定时渠道和水库的贡献，但许多结果实际上是一般的，并且适用于减少频道上可能观察次数的任何侧渠道和技术。来自信息流研究的思想（例如通道容量和改进顺序关系）的思想的琐碎（有些非常规）的使用。
This paper investigates the effect of bucketing in security against timing-channel attacks. Bucketing is a technique proposed to mitigate timing-channel attacks by restricting a system’s outputs to only occur at designated time intervals, and has the effect of reducing the possible timing-channel observations to a small number of possibilities. However, there is little formal analysis on when and to what degree bucketing is effective against timing-channel attacks. In this paper, we show that bucketing is in general insufficient to ensure security. Then, we present two conditions that can be used to ensure security of systems against adaptive timing-channel attacks. The first is a general condition that ensures that the security of a system decreases only by a limited degree by allowing timing-channel observations, whereas the second condition ensures that the system would satisfy the first condition when bucketing is applied and hence becomes secure against timing-channel attacks. A main benefit of the conditions is that they allow separation of concerns whereby the security of the regular channel can be proven independently of concerns of side-channel information leakage, and certain conditions are placed on the side channel to guarantee the security of the whole system. Further, we show that the bucketing technique can be applied compositionally in conjunction with the constant-time-implementation technique to increase their applicability. While we instantiate our contributions to timing channel and bucketing, many of the results are actually quite general and are applicable to any side channels and techniques that reduce the number of possible observations on the channel. It is interesting to note that our results make non-trivial (and somewhat unconventional) uses of ideas from information flow research such as channel capacity and refinement order relation.