1. A computer implemented method for provisioning an OTP generator, the method comprising: selecting one or more variance techniques from a set of variance techniques, wherein the variance technique is given by the function OTP=H(F(SKC, SKPC),InputSet), wherein the InputSet is a set comprising K and Time, wherein H is a Hash; wherein K is a key, wherein SKC is a Symmetric Key certificate, F is a function for use in a variance technique for OTP generation, and wherein SKPC is a Symmetric Key Policy Certificate; provisioning the OTP generator with the one or more variance techniques; and enabling a validator to determine which authentication technique is used by the OTP generator.