Patent ID: 11902428
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 6:
7. A method for generating a shared key for executing encrypted communication between a communication apparatus and another communication apparatus from among a plurality of communication apparatuses according to an authenticated key exchange protocol using ID-based encryption, the method comprising:
generating a short-term private key by using a first element on coset modulo a prime number from a private key of the communication apparatus;
generating a short-term public key of the communication apparatus by using a second element on coset modulo the prime number from the short-term private key;
generating private information associated with the communication apparatus by using a third element on coset modulo the prime number from the short-term private key, a short-term public key generated by said another communication apparatus, public information associated with the communication apparatus and said another communication apparatus; and
generating the shared key for executing encrypted communication with said another communication apparatus by executing a pairing operation, wherein the pairing operation comprises computing on an elliptic curve using the private key of the communication apparatus and the private information associated with the communication apparatus.