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SUMMARY:Mitigating Side Channels in Deduplicating Cloud Storage
DTSTART:20181120T101500
DTSTAMP:20260407T101400Z
UID:c5d3787e8fb3b14d3b9e402871e98c3b70d4f46d53b1ad694fedd1cc
CATEGORIES:Conferences - Seminars
DESCRIPTION:Dr. Mohsen Toorani\, Department of Informatics\, University of
  Bergen\nAbstract: \nOutsourced storage is by now strikingly prevalent fo
 r individuals and enterprises. Cloud storage providers (CSPs) use deduplic
 ation for saving bandwidth and storage which helped them to reduce the cos
 ts tremendously. Deduplication is the process by which CSPs only store one
  copy of each file\, irrespective of how many times that file is uploaded.
  Client-side deduplication\, where the client only uploads the file upon t
 he request of the server\, provides significant storage and bandwidth savi
 ngs but introduces some security concerns. An adversary can exploit side-c
 hannel information in several attack scenarios when deduplication takes pl
 ace at the client side\, leaking information on whether a specific plainte
 xt exists in the cloud storage. In this talk\, we elaborate on these attac
 k scenarios on deduplicating cloud storage systems and discuss some possib
 le countermeasures\, specifically the method of probabilistic uploads. We 
 introduce formal definitions for deduplication strategies and their securi
 ty in terms of adversarial advantage. Using these definitions\, we provide
  a criterion for designing good strategies and then prove a bound characte
 rizing the necessary trade-off between security and efficiency. Generalizi
 ng existing security definitions\, we introduce formal security games for 
 some possible adversaries in this domain and show that games representing 
 all natural adversarial behaviors are in fact equivalent. These results al
 low users and practitioners alike to accurately assess the vulnerability o
 f deployed systems to this real-world concern and identify the steps requi
 red to mitigate the security risks. \n \nBiography\nMohsen Toorani is a 
 postdoctoral research fellow at the Department of Informatics at the Unive
 rsity of Bergen. He received his Ph.D. from the University of Bergen in 20
 15. Since 2016\, he has been working on a collaborative project with the N
 orwegian University of Science and Technology on Cryptographic Tools for C
 loud Security. His research interests include cryptographic protocols and 
 primitives and security of distributed systems. He has served as the edito
 rial board member\, TPC member\, and reviewer for several journals and con
 ferences and is a member of the IACR\, IEEE\, and ACM. 
LOCATION:BC 420 https://plan.epfl.ch/?room==BC%20420
STATUS:CONFIRMED
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