摘要 |
In a system for the transmission of confidential data between a transmitter (1) and a receiver (3), the transmitter (1) transmits a standard key E to the receiver (3). The standard key E preferably is a random number generated within the transmitter (1). An element at the location of the transmitter (1) calculates an intrinsic key R1 for coding the data to be transmitted, and an element at the location of the receiver calculates an intrinsic key R2 for decoding the data. The calculation of each of the intrinsic keys R1 and R2 is accomplished in each case by a microprocessor (4' and 5') situated within a portable object (4 and 5) which also includes a memory (4'' and 5'') storing a program, a secret code S, and an identification code In. The intrinsic keys R1 and R2 are each calculated as a function of the secret code S, the identification code In, and the standard key E. The portable objects at the transmitter and receiver ends of the system must be matched.
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