Patent ID: 8280059
Filing Date: 2012-10-02
Classification: H04L

Abstract:
1. A method for generating a group key, wherein system parameters are selected based on an elliptic curve, the method comprising: forming, by group members, a star-shaped structure, and selecting an organizer from the group members; randomly selecting, by the group members, DH secret values according to the system parameters individually, generating DH public values individually according to the system parameters and the selected DH secret values, and broadcasting the DH public values in the group; selecting, by the organizer, a secret exponent after receiving the DH public values of the other group members, computing an intermediate message DH value according to the secret exponent, generating an intermediate message carrying the intermediate message DH value, broadcasting the intermediate message in the group, and generating a group key according to the DH secret value selected by the organizer and the DH public values of the other group members; and computing, by the other group members, the DH secret value selected by the organizer according to the intermediate message after receiving the intermediate message and the DH public value of the organizer, verifying the computed DH secret value selected by the organizer to be correct according to the received DH public value of the organizer, and generating a group key according to the DH secret value selected by the organizer and the DH public values of the other group members; wherein the computing the intermediate message DH value according to the secret exponent further comprises: wherein the generating the intermediate message carrying the intermediate message DH value further comprises: or