International Association
for Cryptologic Research

We present a novel mechanism that allows a client

to securely outsource his private data to the cloud while at the same

time to delegate to a third party the right to run

certain algorithms on his data. The mechanism is

privacy-preserving, meaning that the third party only learns the result

of his algorithm on the client\'s data, while at the same time the access

pattern on the client\'s data is hidden from the cloud. To achieve this we

combine recent advances in the field of Oblivious RAM and Secure Two-Party

Computation: We develop an Oblivious RAM which is ran between the cloud and a

proxy server, and which does not need the data to be decrypted at any

point. The evaluation on the data is done by employing Yao\'s garbled

circuit solution for Secure Two-Party Computation.