A method for one-time password generation, the one-time password being used for user authentication by a restricted resource. The one-time password is generated by means of a mathematical algorithm in a user-specific device, and the one-time password is generated by the mathematical algorithm using at least one user-specific password generation parameter. A first password generation parameter is used for generating a first one-time password for use in user authentication by a first restricted resource, and a second password generation parameter is used for generating a second one-time password for use in user authentication by a second restricted resource, the second restricted resource being different from the first restricted resource, and the first and second password generation parameters being distinct.