Active protocol discoverer based on grammatical evolution

Abstract

The paper presents a proposition of a system of protocol discovering (Protocol Discoverer) developed on the basis of Grammatical Evolution techniques. Unlike numerous other solutions based solely on observing messages between participants of a conversation, our Protocol Discoverer is an active participant which generates messages and sends them to the system for which the protocol is to be identified. This solution allows not only for identifying typical behaviors of participants within a protocol, but also for finding anomalous behaviors (the ones which normally do not occur between participants using a defined protocol). In order to generate the description of a protocol in the form of a context-free grammar, the solution presented in the article is based on the evolutionary approach using Grammatical Evolution by Grammatical Evolution. Universal grammar is the basis for creating evolutionary solution grammars which describe particular pairs of requests-responses appearing in the protocol.