Patent ID: 7610487

Claim:
One or more computer storage media having computer executable instructions, that when implemented, perform a method for generating a security code for communication by a human user to a device, the method comprising: a) generating by a computing device a hash value based on a combination of a modifier and a first data value; b) repeating the operations of generating a hash value to generate a plurality of hash values, wherein each time the generating operation is repeated the modifier is changed; c) terminating the repeating when a termination condition is met, the termination condition comprising a time parameter specifying a time limit for the repeating operation and further comprising a probability below a probability threshold that a more secure hash value will be generated within a remaining time of the time limit; d) selecting by a computing device a second hash value from the plurality of hash values; e) generating by a computing device a first hash value based on a combination of the modifier associated with the second hash value and a second data value; f) generating by a computing device a security code for communication by the human user, the security code containing at least a portion of the first hash value; and g) communicating by a computing device the security code to the human user.