Patent ID: 8752148

Claim:
A method of authenticating an entity using a one-time password, the method comprising: initializing a non-volatile memory of a hardware device with a pre-produced sequence of one-time passwords, each one-time password in the pre-produced sequence of one-time passwords being produced by an algorithm; indexing into the non-volatile memory of the hardware device upon a request for a one-time password to read the one-time password; and outputting the one-time password to the entity; wherein indexing includes dividing a numeric value used for indexing by a number of one-time password elements in the non-volatile memory, using the result as the offset to read a first one-time password from the non-volatile memory, using the remainder of the division as an offset to read a second one-time password from the non-volatile memory, and exclusive-oring the first one-time password and the second one-time password to produce the one-time password.