Group Key Agreement(GKA)is an important research point in key establishment field. This paper proposes a new ID-based GKA protocol in ternary tree structure. It also considers the situation when some participants change. It discusses the security and computational cost of the new scheme. The result shows that the new protocol realizes the secure key agreement with lower computational cost.
Group Key Agreement(GKA)is an important research point in key establishment field. This paper proposes a new ID-based GKA protocol in ternary tree structure. It also considers the situation when some participants change. It discusses the security and computational cost of the new scheme. The result shows that the new protocol realizes the secure key agreement with lower computational cost.
ID-based group key agreement (GKA) has been increasingly researched with the advantage of simple public key management. However, identities of group members can be exposed in the ID-based GKA protocol, so eavesdroppers can easily learn who belongs to the specific group. Recently, Wan et al. proposed a solution for this problem, an anonymous ID-based GKA protocol, which can keep group memberspsila anonymity to outside eavesdroppers; nevertheless, the protocol has some security flaws. This paper shows that Wan et al.psilas GKA is insecure against colluding attack and their joining/leaving protocols do not guarantee forward and backward secrecy. We also propose a new forward secure ID-based GKA with anonymity from enhancing Wan et al.psilas joining/leaving protocols. Our scheme provides forward and backward secrecy and is essentially just efficient as Wan et al.psilas scheme.
Group key exchange protocols play main role in group applications such as computer networks, telecommunication and military systems. Given the wide range of usage of group applications, research and design of these protocols can play an important role in securing international exchanges, trade and military issues. Most existing group key exchange protocols establish multi-party or group key exchange protocols based on extending the two party well known Diffie- Hellman key exchanges. The security of these protocols is based on this assumption that difficulty of solving group Dif- fie-Hellman problem can be reduced to the difficulty of two party Diffie-Hellman problems. In spite of this assumption, Group key exchanges are not simply extension of two party protocols. In fact there are many differences and challenges that must be considered in design and implementation of these protocols. This difference is due to essential difference between peer to peer communication and group communication. In group communication in addition to considering the main goal e.g. obtaining group session key, consideration of group member changing is important too. In this paper, a Dynamic ID-based Group Key Agreement protocol based on Weil pairing is proposed. This complete ternary tree struc- ture is used and dynamic changes in group are considered too. Finally we show that the proposed protocol is more effi- cient than other protocols with similar structure and also satisfies all known security requirements .
In 2009, Zeng Ping et al. proposed a new Group Key Agreement protocol Based on the ID-AGKA protocol which uses full binary tree structure and each tree node represents a user. Their protocol support users to join or leave the group at any time and the session key will be changed with the users' dynamic changes. In this paper, we point out that Zeng Ping et al.'s Group Key Agreement protocol is non-authenticated and easy to be forged or modified. Then we give a method that attacker can force all group members accepted the modified session private key in BR security model. So, It means that the Zeng Ping et al.'s Protocol can not meet the attribute of implicit key authentication and key control. Finally, we propose an improved protocol to overcome this problem.
Aiming at the fact that the concurrent group key agreement( GKA) protocol is discussed only within the isolate model,and based on m-ary tree decisional Diffie-Hellman within the framework of universally composable( UC) security,a group key agreement protocol is designed,and the ideal functionality model for GKA protocol formulated. The security modular design and implementation of GKA protocol indicates that this protocol could meet the requirement of UC security. Compared with the similar protocol of GKA,this new protocol has the advantages of less communication and computation overhead,while supports group members in their dynamic joining and exiting.
Through the group key agreement, all group members could negotiate a common session key which is used in later secure communication.While simple GKA cannot provide enough security to resist the adversary's attack, and the malicious damage during the agreement makes the authenticated key agreement particularly important.In identity-based authentication, user's unique identity information is used as the public key, which makes it exempt from a series of management of the certification in public-key infrastructure.Thereby, the identity-based key agreement can simplify the key management procedures and reduce the risk of failure at the certification authority.Recently, several identity-based group key agreement protocols have been proposed, however most of them are either vulnerable to impersonation and replay attack or inefficient and unscalable.This paper proposes a novel authenticated group key agreement protocol which is based on bilinear pairings.It needs two rounds to negotiate the session key, and the low computational complexity makes the protocol efficient and scalable.Meanwhile, our protocol also ensures the forward and backward secrecy and the key independence.Under the Decisional Diffie-Hellman assumption, our protocol is proved to be secure against the adversary. 1.
The application of intelligent computing in Internet of Things (IoTs) makes IoTs systems such as telemedicine, in-vehicle IoT, and smart home more intelligent and efficient. Secure communication and secure resource sharing among intelligent terminals are essential. A secure communication channel for intelligent terminals can be established through group key agreement (GKA), thereby ensuring the security communication and resource sharing for intelligent terminals. Taking into account the confidentiality level of the shared resources of each terminal, and the different permissions of the resource sharing of each terminal, a GKA protocol for intelligent IoTs is proposed. Compared with previous work, this protocol mainly has the following advantages: (1) The hidden attribute identity authentication technology can achieve the security of identity authentication and protect personal privacy from being leaked; (2) Only intelligent terminals satisfying the threshold required of the GKA can participate in the GKA, which increases the security of group communication; (3) Low-level group terminals can obtain new permissions to participate in high-level group communication if they meet certain conditions. High-level group terminals can participate in low-level group communication through permission authentication, which increases the flexibility and security of group communication; (4) The intelligent terminals in the group can use their own attribute permission parameters to calculate the group key. They can verify the correctness of the calculated group key through a functional relationship, and does not need to exchange information with other members in the same group. Under the hardness assumption of inverse computational Diffie-Hellman problem and discrete logarithm problem, it is proven that the protocol has high security, and compared with the cited literatures, it has good advantages in terms of computational complexity, time cost and communication energy cost.