The Block-based Mobile PDE Systems Are Not Secure - Experimental Attacks
The Block-based Mobile PDE Systems Are Not Secure - Experimental Attacks
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DOI：
10.48550/arxiv.2203.16349
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发表时间：
2022-03
期刊：
影响因子：
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通讯作者：
Niusen Chen;Bo Chen;Weisong Shi
中科院分区：
文献类型：
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作者：
Niusen Chen;Bo Chen;Weisong Shi
如今，移动的设备已被广泛用于存储和处理敏感数据。为了确保敏感数据的机密性，主流移动的操作系统（如Android和iOS）中通常集成了全磁盘加密（FDE）。然而，FDE不能防御强制攻击，其中对手可以迫使设备所有者公开解密密钥。为了对抗强制性攻击，合理可否认加密（PDE）被用来合理地否认敏感数据的存在。然而，大多数现有的用于移动的设备的PDE系统被部署在块层，并且遭受可否认性妥协。已经观察到，在文献中没有现有的作品已经实验证明了上述的妥协，我们的工作通过实验确认块层移动的PDE系统的可否认性妥协的桥梁这一差距。我们已经建立了一个移动终端测试床，它由一个主机计算设备和闪存设备。此外，我们在测试平台的块层部署了隐藏卷PDE和隐写文件系统，并执行了磁盘取证，以评估原始NAND闪存上的潜在危害。我们的实验结果证实，在实践中，对手确实有可能通过访问原始NAND闪存来破坏块层PDE系统。我们还讨论了在真实的世界中执行此类攻击时可能出现的问题。
Nowadays, mobile devices have been used broadly to store and process sensitive data. To ensure confidentiality of the sensitive data, Full Disk Encryption (FDE) is often integrated in mainstream mobile operating systems like Android and iOS. FDE however cannot defend against coercive attacks in which the adversary can force the device owner to disclose the decryption key. To combat the coercive attacks, Plausibly Deniable Encryption (PDE) is leveraged to plausibly deny the very existence of sensitive data. However, most of the existing PDE systems for mobile devices are deployed at the block layer and suffer from deniability compromises. Having observed that none of existing works in the literature have experimentally demonstrated the aforementioned compromises, our work bridges this gap by experimentally confirming the deniability compromises of the block-layer mobile PDE systems. We have built a mobile device testbed, which consists of a host computing device and a flash storage device. Additionally, we have deployed both the hidden volume PDE and the steganographic file system at the block layer of the testbed and performed disk forensics to assess potential compromises on the raw NAND flash. Our experimental results confirm it is indeed possible for the adversary to compromise the block-layer PDE systems by accessing the raw NAND flash in practice. We also discuss potential issues when performing such attacks in real world.