Abstract: A data carrier (100) is described for use with a reader for the secure transmission of information. The data carrier (100) comprises an identification number associated with the data carrier (100) and a memory for storing a one-time pad and data. The one-time pad is uniquely associated with the identification number. The data carrier (100) further comprises an encryption circuit for encrypting the data with the one-time pad, and a controller to prevent reuse of bits in the one-time pad. The reader comprises a generator to generate the one-time pad via one of the following: a look-up table, and a pseudorandom number generator operating on a secret key and the identification number of the data carrier.

Abstract: A key (10) includes a transceiver core (12) that couples to antenna electrodes that include all or part of a key shank (11) and an electrically conductive surface (16). The transceiver core (12) utilizes these electrodes (11 and 16) to capacitively transceive information with a reader (41). The reader (41) may, in turn, utilize all or part of a keyed lock cylinder (43) as an antenna electrode.