To date, most identity-based key agreement protocols are based on a single PKG (Private Key Generator) environment. In 2002, Chen and Kudla proposed an identity-based key agreement protocol for a multiple PKG environment, where each PKG shares identical system parameters but possesses a distinct master key. However, it is more realistic to assume that each PKG uses different system parameters. ...

To achieve security in the networks, it is important to be able to encrypt and authenticate messages sent between the users. Keys for encryption and authentication purposes must be agreed upon by the users in the networks. Three new pairwise key agreement protocols based on Weil pairing are proposed in this paper. In those protocols, all the users share common secret information. They may arran...

Recently, Al-Riyami and Paterson [1] proposed four authenticated tripartite key agreement protocols which make use of Weil pairing. In this paper, we show that the protocols are insecure against the man-in-the middle attack, key compromise impersonation attack and several known-key attacks.

In this paper we analyse the security of two authenticated group key agreement schemes based on the group key agreement protocol of Burmester and Desmedt. One scheme was proposed by Burmester and Desmedt, and uses a separate authentication scheme to achieve authentication among the participants. We show that this scheme suffers from a number of security vulnerabilities. The other scheme was gen...

Decentralized group key management schemes for supporting secure group communication systems have been studied in the two flavors of contributory key agreement and decentralized key distribution. However, the primary focus has been on the former because the latter have been criticized for additional overheads of establishing secure channels and for the possibility of weak keys produced by the g...

In 1976, Diffie and Hellman in their path breaking paper [5] proposed a two party key agreement protocol based on finite field. Diffie – Hellman Key Exchange Protocol [DH protocol] has unique importance in two party wireless communication scenarios. After this protocol several protocols have been proposed bases on DH protocol but the Man in the middle attack raises a serious security concern on...

E-payment scheme allows two users to securely exchange e-cash and digital product over an open network. A problem in the across administrative domains E-payment scenarios is how the participants can carry out the exchange between administrative domains. In other words, the participants are administrated by two trusted administrators respectively. How can they verify their identities each other?...

Three-party EKE was proposed to establish a session key between two clients through a server. However, three-party EKE is insecure against undetectable on-line and off-line password guessing attacks. In this paper, we first propose an enhanced three-party EKE to withstand the security risk in three-party EKE. We also propose a verifier-based three-party EKE that is more secure than a plaintext-...

In the internet environment, it is desirable for a user to login different servers by keying the same password and using the same smart card. This paper proposes an authentication and key agreement scheme with key confirmation for multi-server environments. Compared with the previous authentication and key agreement schemes for multi-server environments, the new scheme holds many merits. It sat...

Using smart cards, remote user authentication and key agreement can be simplified, flexible, and efficient for creating a secure distributed computers environment. Addition to user authentication and key distribution, it is very useful for providing identity privacy for users. In this paper, we propose novel user authentication and key agreement schemes with privacy protection. We first propose...