A kind of compression method and device of DFA matrix

Abstract

The invention discloses a method and a device for compressing a DFA matrix. The method comprises the steps of acquiring the determined DFA matrix of a finite state automaton and dividing lines of the DFA matrix into a plurality of groups; respectively selecting out an element value with the largest occurrence number in each row in lines belonging to the same group, and obtaining a kernel of the group; obtaining special element values in lines belonging to the same group and establishing a first corresponding relation and a second corresponding relation, wherein the first corresponding relation is the corresponding relation between groups and kernels, and the second corresponding relation is the corresponding relation among groups, lines and rows where the special element values are positioned; storing the kernels, the special element values, the first corresponding relation and the second corresponding relation. By means of the method and the device for compressing the DFA matrix, the compressing rate of the DFA matrix can be increased, the precondition that continuous same states exist in the rows of the DFA matrix is not required when the DFA matrix is compressed, and the error-tolerant rate is relatively high.

Description

technical field [0001] The present invention relates to the field of digital processing, in particular to a method and device for compressing a deterministic finite state automaton (English: Deterministic Finite Automaton, DFA for short) matrix. Background technique [0002] With the explosive expansion of the Internet scale and the rapid development of network technology, network security issues are becoming more and more serious. Traditional firewalls can no longer meet today's complex and changeable network security needs. In this case, the industry has developed an intrusion detection system (English: Intrusion-Detection System, IDS for short). IDS is a network security system that monitors network transmission in real time, issues an alarm or takes active response measures when suspicious data packets are found, and can provide real-time protection for computer network systems in the face of internal attacks, external attacks and misoperations. Help computer network sy...

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Problems solved by technology

However, there is a problem with the jump table using this DFA: when a large number of regular expressions are compiled into DFA, it occupies a large storage space, making the retrieval speed slow

[0013] However, the above method is only effective under the condition that the columns of the DFA matrix have the same continuous state, the error tolerance rate is low, and one bit in the bitmap can only represent one state, and a large amount of data is still required to record the state. The DFA matrix The compression rate is not high

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