A method for checking authentication functions of an authentication between a mobile radio network and a mobile terminal that can be operated in the mobile radio network and/or a mobile subscriber identification module, USIM, that allows a mobile terminal that can be operated in the mobile radio network to have an authenticated access to the mobile radio network, comprising the steps executed by the mobile terminal and/or the mobile subscriber identification module, USIM: receiving, within the scope of the authentication, an authentication vector, AV, comprising a random number, RAND, an expected reply message, XRES, codification values, CK, data integrity values, IK, and an authentication token, AUTN, wherein the authentication token comprises a sequence number, SQN, an information parameter, AMF, and an authentication code, MAC, verifying the authentication token, AUTN, while using the mobile subscriber identification module, USIM, generating an expected authentication code, XMAC, from a key value, K, stored by the mobile subscriber identification module, USIM, the random number, RAND, the sequence number, SQN, and the information parameter, AMF, comparing the generated expected authentication code, XMAC, with the authentication code, MAC, of the authentication token, AUTN, and generating and transmitting at least one reply message, RES, AUTS, to the mobile radio network in dependence on the result of the comparison for the purpose of an authentication of the terminal and/or the mobile subscriber identification module, USIM, in the mobile radio network, characterized by using parameters that are managed in a modifiable manner by means of the mobile terminal and/or by means of the mobile subscriber identification module, USIM, for generating the reply message, and checking the behaviour of the authentication functions of the authentication by creating a relation between the parameters managed in a modifiable manner and the result of the authentication. receiving, within the scope of the authentication, an authentication vector, AV, comprising a random number, RAND, an expected reply message, XRES, codification values, CK, data integrity values, IK, and an authentication token, AUTN, wherein the authentication token comprises a sequence number, SQN, an information parameter, AMF, and an authentication code, MAC, verifying the authentication token, AUTN, while using the mobile subscriber identification module, USIM, generating an expected authentication code, XMAC, from a key value, K, stored by the mobile subscriber identification module, USIM, the random number, RAND, the sequence number, SQN, and the information parameter, AMF, comparing the generated expected authentication code, XMAC, with the authentication code, MAC, of the authentication token, AUTN, and generating and transmitting at least one reply message, RES, AUTS, to the mobile radio network in dependence on the result of the comparison for the purpose of an authentication of the terminal and/or the mobile subscriber identification module, USIM, in the mobile radio network, characterized by using parameters that are managed in a modifiable manner by means of the mobile terminal and/or by means of the mobile subscriber identification module, USIM, for generating the reply message, and checking the behaviour of the authentication functions of the authentication by creating a relation between the parameters managed in a modifiable manner and the result of the authentication.