METHOD FOR ENCRYPTION AND TRANSMISSION OF ENCRYPTED VOICE DATA IN GSM-900 AND DCS-1800 CELLULAR MOBILE COMMUNICATION NETWORKS Russian patent published in 1999 - IPC

FIELD: confidential communication equipment. SUBSTANCE: method involves converting voice data into digital representation, encoding it using voice conversion algorithm, and additional encryption using key pairs which are hidden from other parties. Then method involves transmission of this information from user to user through duplex communication channel for data transmission (as computer files); this channel is provided by GSM (DCS) network. Simultaneously upon reception method involves decryption and digital-to-analog converting of information which is received from information channel. Voice conversion and encryption/decryption features are provided by special mobile user set which is connected to standard radio equipment (mobile terminal sets) through asynchronous serial port RS-232 which is designed for connection of computer. In this duplex transparent data transmission channel provided by GSM-900 AND DCS-1800 cellular communication networks serves as transport for transmission of encrypted voice. EFFECT: increased security of information transmission, impossibility of decryption of information intercepted in arbitrary communication system interface. 2 dwg