Method and device for introducing a service key into a terminal
First Claim
1. A method for introducing a service key into a terminal for decrypting encrypted service data transmitted from a central control station to the terminal comprising the steps of:
- producing an initialization value in a terminal programming device which has no direct communication link to said central control station;
producing in the terminal programming device a decoding key from the initialization value and an algorithm;
transmitting the decoding key and the initialization value from the terminal programming device to the terminal;
storing the transmitted decoding key in the terminal;
transmitting the initialization value from the terminal to the central control station;
producing in the central control station a coding key matching the decoding key using the initialization value and the algorithm;
coding the service key with the coding key;
transmitting the coded service key from the central control station to the terminal;
decoding in the terminal the coded service key using the stored decoding key; and
storing the decoded service key in the terminal.
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Accused Products
Abstract
A simple, efficient and reliable introduction of a service key into a terminal is made possible by a method for introducing a service key into a terminal where the terminal can use the service key to decrypt service data transmitted in encrypted form from a central control station via a public communication channel. The terminal stores a decoding key which is produced from an initialization value by a terminal programming device using an algorithm. The central control station uses an algorithm corresponding to the algorithm and initialization value in the terminal programming device in order to produce a coding key matching the decoding key. The service key stored in the central control station is coded using the coding key and is transmitted to the terminal where it is decoded using the stored decoding key.
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Citations
6 Claims
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1. A method for introducing a service key into a terminal for decrypting encrypted service data transmitted from a central control station to the terminal comprising the steps of:
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producing an initialization value in a terminal programming device which has no direct communication link to said central control station;
producing in the terminal programming device a decoding key from the initialization value and an algorithm;
transmitting the decoding key and the initialization value from the terminal programming device to the terminal;
storing the transmitted decoding key in the terminal;
transmitting the initialization value from the terminal to the central control station;
producing in the central control station a coding key matching the decoding key using the initialization value and the algorithm;
coding the service key with the coding key;
transmitting the coded service key from the central control station to the terminal;
decoding in the terminal the coded service key using the stored decoding key; and
storing the decoded service key in the terminal. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification