Abstract: Deep packet inspection is an advanced packet filter technology, widely used in the network firewall. Pattern matching algorithm based on regular expression has become one of the important methods in achieving DPI. Because the traditional regular expression matching algorithm has higher time complexity, it can not be used in real-time network security protection. In order to improve the real-time of regular expression matching algorithm, this paper proposed the parallel regular expression matches algorithm based on distributed storage. This algorithm counts step data, uses of the distributed storage, and realizes parallel processing. Experimental analysis shows that compared with the traditional serial algorithm, the proposed algorithm increases at least five times in matching speed, and can effectively reduce the time complexity of the algorithm, improve the matching efficiency.

Key words: Regular expression, Pattern matching algorithm, DFA (Deterministic finite automaton)，DPI, Distributed storage