Patent ID: 7219235
Filing Date: 2007-05-15
Classification: H04L

Abstract:
1. A method of unlocking a locked structure comprising the steps of: (a) creating a cryptogram at an encryption device located remote of said locked structure, said encryption device having a first clock, by encrypting a time representation based upon said first clock with an encrypting cryptographic key for said locked structure using an encryption algorithm; (b) transporting said cryptogram from said encryption device to said locked structure; (c) inputting said cryptogram into a decryption device at said locked structure, said decryption device having: (d) decrypting said cryptogram using said decryption algorithm and said decrypting cryptographic key at said decryption device to produce a decrypted time representation; (e) comparing said decrypted time representation with a time representation based upon said second clock; and (f) unlocking said lock at said structure if said decrypted time representation meets a time-based criteria relative to said time representation based upon said second clock.