Abstract: A method and system for selectively disrupting voice modulated radio communications circuits wherein the original communication is recorded, delayed for a selected period then synchronized with a transmitted signal and reinjected into the transmitted signal thereby preventing the intended recipient of the signal from obtaining any intelligence therefrom.

Abstract: The present invention teaches apparatus, method and use for a portable shopper product information remote unit. A plurality of remote units are provided to shoppers within a retail establishment which uses bar code scanners at a cashier's counter to record products of the shopper's purchase. The units are retrieved from each shopper subsequent to a finished purchase and returned to a central maintenance system. The remote units' batteries are recharged and data updated with at least updated pricing information such that the bar code scanners at the cashier's counters and the remote units are provided with the same updated product pricing information.

Abstract: A method and system for disrupting discrete keyed continuous wave radio communications wherein the discrete keyed continuous wave communications signal conveys intelligence by virtue of the duration and spacing of a coded series of characters by insertion of additional character representing signals within the spaces between the characters of the original signal, thereby changing the coded series and thus depriving the intended recipient of the original intelligence.

Abstract: A privacy communication method and system which utilizes coherent, continuously changing frequencies for keyed, pulsed, and voice communications. A synthesized swept frequency or "chirp" signal imparts a privacy or secure communications capability to the communications signal by virtue of the random or pseudo-random nature of the transmitted signals which is programmed.

Abstract: An automatic authentication apparatus utilizing a random code generator to provide a challenge signal for transmission to a remote station. The challenge code also being converted to a response code at the sending station and stored therein. The receiving station generating a response signal to the challenge signal and transmitting the response signal to the sending station. The sending station comparing the two response signals to determine that communications with a friendly station has been established.