Patent ID: 9660983
Date: 2017-05-23
CPC Classifications: G06F,G09C,H04L

Claim:
1. A method to authenticate, the method comprising: receiving, by a computing device of a plurality of computing devices of a user, a request for a one time password; automatically selecting, by the computing device and in response to the request, a counter to use in calculating the requested one time password, the selected counter being selected from a synchronous set of copied counters copied from a corresponding set of original counters maintained by an authenticator, the synchronous set of copied counters is a mutually exclusive set of counters assigned to the computing device among the plurality of computing devices of the user; the mutually exclusively set is a part of a larger superset of the original counters maintained by the authenticator, where no other counters except the assigned exclusive set of counters are downloaded from the authenticator to the computing device, said automatic selecting being carried out on one of a random, round robin or sequential basis from among the copied counters; wherein, the synchronous set of copied counters having at least three counters and a last selected counter is excluded from being selected by the computing device again; retrieving, by the computing device, a counter value from the selected counter; retrieving, by the computing device, a key value previously downloaded from the authenticator; calculating, by the computing device, the one time password as a function of the retrieved counter value and of the retrieved key value; and outputting, by the computing device, the calculated one time password.