Graduate School and Research Center in Digital Sciences

Seminar: NS Seminar

Monir Azraoui - PhD Student

Corporate communication

Date: April 14, 2015

Location: Eurecom - Salle 103, EURECOM

We present StealthGuard, an efficient and provably secure proof of retrievabillity (POR) scheme. StealthGuard makes use of a privacy-preserving word search (WS) algorithm to search, as part of a POR query, for randomly-valued blocks called watchdogs that are inserted in the file before outsourcing. Thanks to the privacy-preserving features of the WS, neither the cloud provider nor a third party intruder can guess which watchdog is queried in each POR query. Similarly, the responses to POR queries are also obfuscated. Hence to answer correctly to every new set of POR queries, the cloud provider has to retain the file in its entirety. StealthGuard stands out from the earlier sentinel-based POR scheme proposed by Juels and Kaliski, due to the use of WS and the support for an unlimited number of queries by StealthGuard.

NS Seminar