Key management system for open communication environments

摘要: A telecommunications security device for use on the communication medium includes a first and second unit each arranged to be inserted into example telephone line adjacent user device. The units are identical therefore either can act as central computer access port with other providing one of set remote units. Each separable memory module all modules having storing information. information stored plurality pairs random signals pair request signal code. receipt call provides requesting an ID code from issues signal. On matching received expected transmission gate is opened. used in turn until have been whereupon indicator shows this condition. removed re-written fresh codes. key logic circuit which controls numbers fixed rules allowing authentication and/or encryption against unauthorized access.