While disk encryption is suitable for use in most situations where confidentiality of disks is required, stronger guarantees are required in situations where adversaries may employ coercive tactics to gain access to cryptographic keys. Deniable volumes are one such solution in which the security goal is to prevent an adversary from discovering that there is an encrypted volume. Multiple snapshot attacks, where an adversary is able to gain access to two or more images of a disk, have often been proposed in the deniable storage system literature; however, there have been no concrete attacks proposed or carried out. We present the first multiple snapshot attack, and we find that it is applicable to most, if not all, implemented deniable storage systems. Our attack leverages the pattern of consecutive block changes an adversary would have access to with two snapshots, and demonstrate that with high probability it detects moderately sized and large hidden volumes, while maintaining a low false positive rate.
翻译:虽然磁盘加密在多数需要磁盘保密的情况下适合使用,但在对手可能采用胁迫手段获取加密密钥的情况下,需要更有力的保障。可否认的数量是安全目标之一是防止对手发现有加密的容量。在可否认的存储系统文献中,常常提出多次即时攻击,即对手能够获取两个或两个以上的磁盘图像;然而,没有提议或实施具体的攻击。我们提出了第一次多次即时攻击,我们发现它适用于大多数甚至全部已实施的可否认的存储系统。我们的攻击利用连续街区改变的模式,对手可以用两张快照进入,并表明它极有可能探测到中小和大隐藏的数量,同时保持低的假正率。