A shared secret, conference key, must be established among members to securely communicate among them. The Diffie-Hellman is often used for the conference key establishment. In a heterogenous network, the participants have different resources. Therefore, different burden should be placed on different participants. However, most protocols did not address this problem. Wade Trappe et. al. address...

Key establishment is any process whereby a shared secret key becomes available to two or more parties, for subsequent cryptographic use such as symmetrickey encryption. Though it is widely known that the primitive of encryption is different from key establishment, we find some researchers have confused the two primitives. In this note, we shall clarify the fundamental difference between the two...

The advantage of ID-based system is the simplification of key distribution and certification management; a user can directly use his identity as his public key instead of an arbitrary number, thus at the same time he can prove his identity rather than providing a certificate from CA. Now a revocable blind signature is becoming more practical; because a complete anonymity can be abused in real w...

In the previous lecture, we discussed the concept of Secret-Key Encryption. However, this scheme has a major limitation in the fact that the key has to be shared between the sender and the receiver before any message can be transmitted. There might be several cases where doing this is infeasible if there has been no prior communication between the sender and the receiver. In today’s lecture, we...

In this paper, a novel and efficent password based group key exchange protocol with secret sharing is proposed. Secret sharing technology is usually used to control the privileges of the authorized users to improve the robustness of the system in past years. The results are applied into designing the key exchange protocol directly, which clarify the proposed scheme. The security analysis shows ...

Reply to Comments on " Quantum Key Distribution for d-level systems for generalized Bell states " [Phys. Rev. A, 052331, (2002)] and " Quantum secret sharing based on a reusable Greenberger-Horne-Zeilinger states as secure carriers " [Phys. Abstract We show that the criticisms of two recent comments [1, 2] on the insecurity of quantum key distributions proposed in [3] and [4] and the secret sha...