VERFAHREN ZUR STEUERUNG DER VERTRAULICHKEIT EINER PERSÖNLICHEN MITTEILUNG

摘要

When a call of personal communication at a communication number PID arrives at an exchange (20), the exchange (20) fetches the user information UK corresponding to the number PID and call registration communication terminal identification number SID from a data base (30) and transmits the number PID to a communication terminal (10) (step S3). Upon receiving the response from the terminal (10), the exchange (20) generates a random number R (step S7) and sends the number R to the terminal (10) and, at the same time, generates a secret key K=F(R, UK) from the information UK and the number R (step S10). The terminal (10) generates the secret key K=F(R, UK) from the received number R and the information UK inputted by the user (step 9). The exchange (20) and terminal (10) transmit secreted communication information to each other by using the same secret key K and release the secrecy of the received secret communication information.