Side channels in deduplication: trade-offs between leakage and efficiency
Armknecht, Frederik; Boyd, Colin Alexander; Davies, Gareth Thomas; Gjøsteen, Kristian; Toorani, Mohsen
Chapter
Accepted version
Permanent lenke
http://hdl.handle.net/11250/2488888Utgivelsesdato
2017Metadata
Vis full innførselSamlinger
Originalversjon
10.1145/3052973.3053019Sammendrag
Deduplication removes redundant copies of files or data blocks stored on the cloud. Clientside deduplication, where the client only uploads the file upon the request of the server, provides major storage and bandwidth savings, but introduces a number of security concerns. Harnik et al. (2010) showed how cross-user client-side deduplication inherently gives the adversary access to a (noisy) side-channel that may divulge whether or not a particular file is stored on the server, leading to leakage of user information. We provide formal definitions for deduplication strategies and their security in terms of adversarial advantage. Using these definitions, we provide a criterion for designing good strategies and then prove a bound characterizing the necessary trade-off between security and efficiency.