A method for generating a cryptographic key for implementing a method for controlling access to a resource of a server by a client terminal, with the method being implemented by the client terminal, said terminal being configured to communicate with the server, the client terminal comprising a memory wherein is stored a reference datum (Dref) obtained by applying an encoding method to a reference biometric datum (DBref) and to a legitimate cryptographic key enabling the client terminal to be authenticated with the server during an access control, the stored reference datum (Dref) depending on an error correcting code, the error correcting code being obtained from the legitimate cryptographic key, the method comprising the following steps: - receiving a test biometric datum (DBtest), - applying a decoding method to the test biometric datum (DBtest) and the stored reference datum (Dref), said decoding comprising the implementation of an error decoding method, to obtain a generated cryptographic key (K') such as: if the test biometric datum (DBtest) corresponds to the reference biometric datum (DBref), the generated cryptographic key (K') is the legitimate cryptographic key, otherwise, the generated cryptographic key (K') is an illegitimate cryptographic authentication key (Ki) that does not enable authentication of the client terminal with the server during an access control, the decoding method thus generating a cryptographic key (K') regardless of the test biometric datum (BDtest), and - using the generated cryptographic key (K') for the implementation of an access control method to a server resource by the client terminal, so that the exchange of information between the client terminal and the server does not take place if only the legitimate cryptographic key is generated. with the method being implemented by the client terminal, said terminal being configured to communicate with the server, the client terminal comprising a memory wherein is stored a reference datum (Dref) obtained by applying an encoding method to a reference biometric datum (DBref) and to a legitimate cryptographic key enabling the client terminal to be authenticated with the server during an access control, the stored reference datum (Dref) depending on an error correcting code, the error correcting code being obtained from the legitimate cryptographic key, the method comprising the following steps: - receiving a test biometric datum (DBtest), - applying a decoding method to the test biometric datum (DBtest) and the stored reference datum (Dref), said decoding comprising the implementation of an error decoding method, to obtain a generated cryptographic key (K') such as: if the test biometric datum (DBtest) corresponds to the reference biometric datum (DBref), the generated cryptographic key (K') is the legitimate cryptographic key, otherwise, the generated cryptographic key (K') is an illegitimate cryptographic authentication key (Ki) that does not enable authentication of the client terminal with the server during an access control, the decoding method thus generating a cryptographic key (K') regardless of the test biometric datum (BDtest), and - using the generated cryptographic key (K') for the implementation of an access control method to a server resource by the client terminal, so that the exchange of information between the client terminal and the server does not take place if only the legitimate cryptographic key is generated. - receiving a test biometric datum (DBtest), - applying a decoding method to the test biometric datum (DBtest) and the stored reference datum (Dref), said decoding comprising the implementation of an error decoding method, to obtain a generated cryptographic key (K') such as: if the test biometric datum (DBtest) corresponds to the reference biometric datum (DBref), the generated cryptographic key (K') is the legitimate cryptographic key, otherwise, the generated cryptographic key (K') is an illegitimate cryptographic authentication key (Ki) that does not enable authentication of the client terminal with the server during an access control, the decoding method thus generating a cryptographic key (K') regardless of the test biometric datum (BDtest), and if the test biometric datum (DBtest) corresponds to the reference biometric datum (DBref), the generated cryptographic key (K') is the legitimate cryptographic key, otherwise, the generated cryptographic key (K') is an illegitimate cryptographic authentication key (Ki) that does not enable authentication of the client terminal with the server during an access control, the decoding method thus generating a cryptographic key (K') regardless of the test biometric datum (BDtest), and - using the generated cryptographic key (K') for the implementation of an access control method to a server resource by the client terminal, so that the exchange of information between the client terminal and the server does not take place if only the legitimate cryptographic key is generated.