A method of authenticating a client to a service via a network includes retrieving a client ID and a lockstep code from a token interfaced with a client device, sending the client ID and the lockstep code to an authentication server as part of a verification request, at the authentication server, comparing the lockstep code to a confirmation lockstep code relating to the client ID, based on the comparison, sending an authentication message from the authentication server, at the authentication server, generating a new confirmation lockstep code, sending the new confirmation lockstep code to the client device, and updating the lockstep code of the token to an updated lockstep code that matches the new confirmation lockstep code.