SECURE AND EFFICIENT OBLIVIOUS DIRECT ACCESS MACHINE WITH MULTIPLE SERVERS IN A MALICIOUS ENVIRONMENT

摘要

An oblivious distributed distribution system is provided using an oblivious random access machine (ORAM) having a balanced ORAM tree structure, each node in the tree being adapted to store blocks of data, the structure comprising at least two portions. The system also includes at least two ORAM servers, each of the servers being adapted to communicate with a client ORAM device and programmed to enable storage of a different subset of the portions of the tree structure using a distributed file system and one Implement a tree-based access procedure of an ORAM using the tree structure, which includes a retrieval phase and a clearing phase. In the retrieval phase, the servers use an authenticated private information retrieval (PIR) protocol to retrieve blocks of data when requested by the client ORAM device. In the clearing phase, the servers use a linear secret sub-scheme.