The disclosure relates to a method and a system for authorising a connection between a computer terminal and a source server, including an initialization phase wherein: the terminal connects to a gateway server, the gateway server sends a secret key to the terminal, the terminal hides the password in a data file by applying an encryption algorithm bootstrapped by the secret key, then deletes the secret key and the password, and a connection phase wherein: the terminal sends the data file containing the password to the gateway server, the gateway server extracts the files password by executing a reverse encryption algorithm bootstrapped by the secret key, and sends the password to the source server without saving it, the source server analysis the received password and authorizes the connection with the terminal if the password is authenticated.