On Some Crypto-messages Parser

Some methods of automatic verification of cryptographic protocols require creating specially designed formal languages based on suitable algebra of terms (called crypto-terms or crypto-messages). Sometimes in verification process it is essential to check whether a given crypto-term is a sub term of another one or in general whether some crypto-term belongs to the specified crypto-Language (a set of some crypto-terms) or not. Another problem is creating the set of all ant chains of subterms of a given term wit h respect to the order introduced by a subterm relation. The main goal of this paper is to present a tool for verification whether crypto-term belongs to the specified crypto-language or not. Our main purpose is to check lexical analysis and syntax analysis. Finally, after checking that a crypto-sentence is correct, we convert it into the special format, purpose was to check lexical analysis and syntax analysis. For our investigation Flex and Bison - the well known grammar tools – have been used. We believe that our tool will be usefull in research on the topic of symbolic verification of cryptographic protocols.