Efficient secure pattern search algorithm

In this paper we describe an efficient protocol for oblivious evaluation of a binary alphabet Deterministic Finite Automata (DFA) between the DFA owner (client) and the input text owner (server). The protocol requires only a single round of client-server communication. The number of server-side computations is linear to the text length and does not depend on the size of the DFA, and the number of client-side computations is linear to the multiplication of the number of the DFA states and text length, and it does not depend on the internal structure of the DFA. Our protocol uses white-box based 1-out-of-2 oblivious transfer protocol as a construction block. As a result, we have no public-key operations in our algorithm. Also, we have developed a test program which implements the protocol and this paper includes the results of benchmarks done for different input data. These results demonstrate the efficiency of the construction and confirm the low computational overhead of server side operations.