implicit and unobserved errors and vulnerabilities issues usually arise in cryptographic protocols and especially in authentication protocols. this may enable an attacker to make serious damages to the desired system, such as having the access to or changing secret documents, interfering in bank transactions, having access to users’ accounts, or may be having the control all over the system. many methods have been used to verify the cryptographic protocols such as logical, algebraic, inductive, and mathematical complexity methods. each of these methods has its special shortages, in addition to the general disadvantages of these methods. nevertheless, no one has tried to use the computational methods as cryptographic protocol’s verifiers. in this thesis, we represent genetic programming – a type of computational methods- as a new verification method for the cryptographic protocols. gaprover; new genetic programming based system has been built and successfully used to verify some known authentication protocols. we wish a new horizon would be opened in the field of cryptographic protocol verification because of this effort. moreover, we believe that further development of this method may solve many problems that encountered by researchers in the field of protocol verification because of the use of formal methods.