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SUMMARY:Privacy and Integrity of Remote Storage and Computation - Olga Ohr
 imenko\, Brown University
DTSTART:20130320T100000Z
DTEND:20130320T110000Z
UID:TALK43839@talks.cam.ac.uk
CONTACT:Microsoft Research Cambridge Talks Admins
DESCRIPTION:Cloud computing provides on demand remote storage and computat
 ion resources at a cost that depends only on the usage rate. However\, the
  loss of the physical control over data and computation raises new challen
 ges in terms of security. These challenges include maintaining privacy of 
 remotely stored data and verification of outsourced computation.\n\nIn thi
 s talk\, we first address the problem of privacy-preserving access to data
  stored with a cloud provider. Storing the data in encrypted form is a key
  component in maintaining the privacy of the data. However\, encrypting th
 e data is not enough since information about the data may be leaked throug
 h the pattern in which users access the data. We show how to achieve effic
 ient privacy-preserving data access using low communication and storage ov
 erhead. Our method is based on a combination of encryption\, which directl
 y hides data values\, and stateless oblivious RAM simulation\, which hides
  the pattern of data accesses. We provide experimental results from our ap
 proach and compare it with a more powerful scheme where a client is allowe
 d to keep a state.\n\nIn the second part of the talk\, we consider the pro
 blem of verification of a very common and computationally intensive outsou
 rced computation: keyword search over a document collection. We present a 
 method that allows a client to verify that the result she receives to her 
 query is complete and sound. We propose a solution that requires the cloud
  provider to compute not only the result\, but also a cryptographic proof 
 of the computation. The client then uses the proof to verify that the list
  of documents returned is correct w.r.t. her query and document collection
 . We show that our solution adds a small overhead: the size of the proof i
 s as large as the query result\, and the verification time for the client 
 is negligible and takes milliseconds.\n\n
LOCATION:Auditorium\, Microsoft Research Ltd\, 21 Station Road\, Cambridge
 \, CB1 2FB
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