Artifice: Data in Disguise

Abstract

With the widespread adoption of disk encryption technologies, it has become common for adversaries to employ coercive tactics to force users to surrender encryption keys and similar credentials. For some users this creates a need for hidden volumes that provide plausible deniability or the ability to deny the existence of sensitive information. Plausible deniability directly impacts groups such as democracy advocates relaying information in repressive regimes, journalists covering human rights stories in a war zone, or NGO workers hiding food shipment schedules from violent militias. All of these users would benefit from a plausibly deniable data storage system. Previous deniable storage solutions only offer pieces of an implementable solution. We introduce Artifice, the first tunable, operationally secure, self repairing, and fully deniable storage system.

With Artifice, hidden data blocks are split with Shamir Secret Sharing to produce a set of obfuscated carrier blocks that are indistinguishable from other pseudo-random blocks on the disk. The blocks are then stored in unallocated space and possess a self-repairing capability and rely on combinatorial security. Unlike preceding systems, Artifice addresses problems regarding flash storage devices and multiple snapshot attacks through comparatively simple block allocation schemes and operational security. To hide the user’s ability to run a deniable system and prevent information leakage, Artifice stores its driver software separately from the hidden data.

Full Paper

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BibTeX

@inproceedings{barker-msst20,
  author       = {Austen Barker and Yash Gupta and Sabrina Au and Eugene Chou and Ethan L. Miller and Darrell D. E. Long},
  title        = {Artifice: Data in Disguise},
  booktitle    = {Proceeding of the Conference on Mass Storage Systems and Technologies (MSST '20)},
  month        = oct,
  year         = {2020},
}