Patent ID: 6658114
Filing Date: 2003-12-02
Classification: H04L

Abstract:
A key management method to prevent illegal eavesdropping in a network system, comprising:dividing session keys of the network system into a plurality of family subkeys and a plurality of communication subkeys; providing a plurality of trusted-key centers for respectively preserving a part of the family subkeys and one of the communication subkeys, and generating a one-way hash value involving the preserved communication subkey and an open information; each of the trusted-key centers passing the hash value to an eavesdropper according to an authority certificate; each of the trusted-key centers interchanging the preserved family subkeys according to the authority certificate to obtain a session key which is passed to the eavesdropper; and the eavesdropper combining all the hash values from the trusted-key centers to obtain a communication key which is accompanied with the session key to eavesdrop an authorized communication.