Countering targeted file attacks using locationguard
Mudhakar Srivatsa, Ling Liu · USENIX Security Symposium · 2005
Serverless file systems, exemplified by CFS, Farsite and OceanStore, have received significant attention from both the industry and the research community. These file systems store files on a large collection of untrusted nodes that form an overlay network. They use cryptographic techniques to maintain file confidentiality and integrity from malicious nodes. Unfortunately, cryptographic techniques cannot protect a file holder from a Denial-of-Service (DoS) or a host compromise attack. Hence, most of these distributed file systems are vulnerable to targeted file attacks, wherein an adversary attempts to attack a small (chosen) set of files by attacking the nodes that host them. This paper presents LocationGuard - a location hiding technique for securing overlay file storage systems from targeted file attacks. LocationGuard has three essential components: (i) location key, consisting of a random bit string (e.g., 128 bits) that serves as the key to the location of a file, (ii) routing guard, a secure algorithm that protects accesses to a file in the overlay network given its location key such that neither its key nor its location is revealed to an adversary, and (iii) a set of four location inference guards. Our experimental results quantify the overhead of employing LocationGuard and demonstrate its effectiveness against DoS attacks, host compromise attacks and various location inference attacks.