CleanOS: Limiting Mobile Data Exposure with Idle Eviction

Yang Tang, Phillip Ames, Sravan Bhamidipati, Ashish Bijlani, Roxana Geambasu, Nikhil Sarda

Proceedings of the 10th USENIX Symposium on Operating Systems Design and Implementation (OSDI’12), Hollywood, CA, October 2012

Abstract

Mobile-device theft and loss have reached gigantic proportions. Despite these threats, today’s mobile devices are saturated with sensitive information due to operating systems that never securely erase data and applications that hoard it on the vulnerable device for performance or convenience. This paper presents CleanOS, a new Android-based operating system that manages sensitive data rigorously and maintains a clean environment at all times. To do so, CleanOS leverages a key property of today’s mobile applications — the use of trusted, cloud-based services. Specifically, CleanOS identifies and tracks sensitive data in RAM and on stable storage, encrypts it with a key, and evicts that key to the cloud when the data is not in active use on the device. We call this process idle eviction of sensitive data. To implement CleanOS, we used the TaintDroid mobile taint-tracking system to identify sensitive data locations and instrumented Android’s Dalvik interpreter to securely evict that data after a specified period of non-use. Our experimental results show that CleanOS limits sensitive-data exposure drastically while incurring acceptable overheads on mobile networks.

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cleanos:osdi2012

Columbia University Department of Computer Science