Low-Computation Oblivious Transfer Scheme for Private Information Retrieval

[[abstract]]The most efficient previous oblivious transfer schemes require 2t rounds of communication to obtain t secret messages. Its computational requirements and bandwidth consumption are quite demanding. Therefore, to guarantee the quality of this growing popular communication service, an efficient t-out-n oblivious transfer scheme is urgently desired. Based on the discrete logarithm, we propose an efficient t-out-n oblivious transfer scheme in this paper. Compared with existing oblivious transfer schemes, our scheme can reduce many computations and communications for both the sender and the receiver. In our scheme, only several modular multiplications and three rounds of communications are needed for a user (receiver) to obtain t messages. Since no modular exponentiation and inverse computations are performed by a user (receiver), our proposed scheme is suitable for the limited computation capacities of receivers such as smart cards or mobile units