Data transmission links
First Claim
1. A method of establishing a secure communications link between a mobile terminal of a mobile communications system and a server, the method comprising:
- retrieving from storage, in the mobile terminal a prime number, p, and generator, g, for a Diffie-Hellman key exchange protocol;
generating a positive integer b less than p−
1 at the terminal;
sending a message including the value of (gbmod p) from the terminal to the server;
determining a shared secret number for the terminal and the server by calculating the value of (gab mod p), where a is a positive integer less than p−
1, at both the terminal and the server, using b and a value y=ga mod p for the server at the terminal, and using a, b, g and p at the server; and
using the shared secret number to establish said secure communications between the terminal and the server.
1 Assignment
0 Petitions
Accused Products
Abstract
This invention generally relates to secure communications links for data transmission and more particularly relates to data communications links in which asymmetric cryptographic techniques are used to establish a secure link using symmetric cryptography.
A method of establishing a secure communications link between a mobile terminal of a mobile communications system and a server, the method comprising: retrieving from storage, in the mobile terminal a prime number, p, and generator, g, for a Diffie-Hillman key exchange protocol; generating a positive integer b at the terminal; sending a message including the value of (gbmod p) from the terminal to the server; determining a shared secret number for the terminal and the server by calculating the value of (gab mod p), where a is a positive integer, at both the terminal and the server, using b and a public value for the server y=ga mod p at the terminal, and using a, b, g and p at the server; and using the shared secret number to establish said secure communications between the terminal and the server. Corresponding software is also provided.
The method facilitates fast and if desired, anonymous, download of software to a mobile communications system terminal.
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Citations
28 Claims
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1. A method of establishing a secure communications link between a mobile terminal of a mobile communications system and a server, the method comprising:
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retrieving from storage, in the mobile terminal a prime number, p, and generator, g, for a Diffie-Hellman key exchange protocol;
generating a positive integer b less than p−
1 at the terminal;
sending a message including the value of (gbmod p) from the terminal to the server;
determining a shared secret number for the terminal and the server by calculating the value of (gab mod p), where a is a positive integer less than p−
1, at both the terminal and the server, using b and a value y=ga mod p for the server at the terminal, and using a, b, g and p at the server; and
using the shared secret number to establish said secure communications between the terminal and the server. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 20, 21, 22, 25, 26)
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18. A method of establishing a secure communications link between a server of a mobile communications system and a mobile terminal, the method comprising:
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retrieving from storage, in the server a prime number, p, and generator, g, for a Diffie-Hellman key exchange protocol;
generating a positive integer b less than p−
1 at the server;
sending a message including the value of (gbmod p) from the server to the terminal;
determining a shared secret number for the server and the terminal by calculating the value of (gab mod p), where a is a positive integer less than p−
1, at both the server and the terminal, using b and a value y=ga mod p for the terminal at the server, and using a, b, g and p at the server; and
using the shared secret number to establish said secure communications between the server and the terminal. - View Dependent Claims (19, 23, 24, 27, 28)
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Specification