Patent ID: 8902040

Claim:
An electronic lock for dynamic controlled access comprising a mechanical locking mechanism; a clock; a microprocessor; a memory storing a hash function and instructions for identifying, based at least partly on a current time, at least two currently valid arguments to be hashed by the hash function to produce a hash, each of the currently valid arguments comprising a currently valid time period that includes the current time, at least two of the currently valid time periods being different time periods, the hash of each currently valid argument returning a currently valid access code, such that at least two respective access codes are valid at the current time; and a human interface device configured to permit a human user to input an access code and to transmit the input access code to the microprocessor; the memory further containing programmed instructions for the microprocessor to receive a signal from the clock indicating the current time, receive the input access code transmitted from the human interface device, compare the input access code to one of the currently valid access codes, the one of the currently valid access codes having been returned by the microprocessor identifying and hashing one of the currently valid arguments, to determine whether the input access code equals the returned valid access code, if the input access code does not equal the returned currently valid access code and the input access code has not yet been compared to all of the currently valid access codes, compare the input access code to another currently valid access code returned by the microprocessor hashing another one of the currently valid arguments, at least until either the input access code is determined to equal one of the currently valid access codes or the input access code has been compared to all of the currently valid access codes and does equal any of the currently valid access codes, and if the input access code is determined to equal one of the currently valid access codes, unlock the mechanical locking mechanism.