Processorless token for producing a one-time password

A hardware device for producing a one-time password, the hardware device comprising:

• a non-volatile memory, the non-volatile memory including a pre-produced sequence of one-time passwords, each one-time password in the sequence of pre-produced one-time passwords comprising an algorithm result;
• a circuit board coupled to the non-volative memory, the circuit board being constructed and arranged to read the one-time password from the non-volatile memory by using an index value to determine a location of the one-time password in the non-volatile memory;
• and
• an output device coupled to the circuit board, the output device being constructed and arranged to output the read one-time password;
• wherein the circuit board is configured to read the one-time password by dividing the index value 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, and using the remainder of the division as an offset to read a second one-time password from the non-volatile memory, the first one-time password and the second one-time password exclusive-ored to produce the one-time password.

A computer readable storage medium with a computer program stored thereon, the computer program upon execution by a processor performing 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.

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 current one-time password to read the one-time password;
• and
• outputting the one-time password to the entity;
• wherein indexing includes (i) deriving, from a numeric value used for indexing, a first index and a second index, (ii) reading a first one-time password from the non-volatile memory using the first index, (iii) reading a second one-time password from the non-volatile memory using the second index, and (iv) combining the first one-time password and the second one-time password together to produce the current one-time password.