Multivariate Broadcast Encryption with Group Key Algorithm for Secured IoT

The expanding and ubiquitous availability of the Internet of Things(IoT)have changed everyone’s life easier and more convenient.Same time it also offers a number of issues,such as effectiveness,security,and excessive power consumption,which constitute a danger to intelligent IoT-based apps.Group managing is primarily used for transmitting and multi-pathing communications that are secured with a general group key and it can only be decrypted by an authorized group member.A centralized trustworthy system,which is in charge of key distribution and upgrades,is used to maintain group keys.To provide longitudinal access controls,Software Defined Network(SDN)based security controllers are employed for group administration services.Cloud service providers provide a variety of security features.There are just a few software security answers available.In the proposed system,a hybrid protocols were used in SDN and it embeds edge system to improve the security in the group communication.Tree-based algorithms compared with Group Key Establishment(GKE)and Multivariate public key cryptosystem with Broadcast Encryption in the proposed system.When all factors are considered,Broadcast Encryption(BE)appears to become the most logical solution to the issue.BE enables an initiator to send encrypted messages to a large set of recipients in a efficient and productive way,meanwhile assuring that the data can only be decrypted by defining characteristic.The proposed method improves the security,efficiency of the system and reduces the power consumption and minimizes the cost.

Provable Efficient Certificateless Group Key Exchange Protocol

Certificateless public key cryptography （CL-PKC） avoids the inherent escrow of identity-based cryptography and does not require certificates to guarantee the authenticity of public keys. Based on CL-PKC, we present an efficient constant-round group key exchange protocol, which is provably secure under the intractability of computation Diffie-Hellman problem. Our protocol is a contributory key exchange with perfect forward secrecy and has only two communication rounds. So it is more efficient than other protocols. Moreover, our protocol provides a method to design efficient constant-round group key exchange protocols and most secret sharing schemes could be adopted to construct our protocol.

A Secure Key Management Scheme for Heterogeneous Secure Vehicular Communication Systems

Intelligent transportation system （ITS） is proposed as the most effective way to improve road safety and traffic efficiency. However, the future of ITS for large scale transportation infrastructures deployment highly depends on the security level of vehicular communication systems （VCS）. Security applications in VCS are fulfilled through secured group broadcast. Therefore, secure key management schemes are considered as a critical research topic for network security. In this paper, we propose a framework for providing secure key management within heterogeneous network. The seeurity managers （SMs） play a key role in the framework by retrieving the vehicle departnre infi^rmation, encapsulating block to transport keys and then executing rekeying to vehicles within the same security domain. The first part of this framework is a novel Group Key Management （GKM） scheme basing on leaving probability （LP） of vehicles to depart current VCS region. Vehicle＇s LP factor is introduced into GKM scheme to achieve a more effieient rekeying scheme and less rekeying costs. The second component of the framework using the blockchain concept to simplify the distributed key management in heterogeneous VCS domains. Extensive simulations and analysis are provided to show the effectiveness and effieiency of the proposed framework： Our GKM results demonstrate that probability-based BR reduees rekeying eost compared to the benchmark scheme, while the blockchain deereases the time eost of key transmission over heterogeneous net-works.

Identity Based Group Key Agreement in Multiple PKG Environment

Secure and reliable group communication is an increasingly active research area by growing popularity in group-oriented and collaborative applications. In this paper, we propose the first identity-based authenticated group key agreement in multiple private key generators （PKG） environment. It is inspired on a new two-party identity-based key agreement protocol first proposed by Hoonjung Lee et al. In our scheme, although each member comes from different domain and belongs to different PKGs which do not share the common system parameters, they can agree on a shared secret group key. We show that our scheme satisfies every security requirements of the group key agreement protocols.

Password-Based Group Key Agreement Protocol for Client-Server Application

The security issue is always the most important concern of networked client-server application. On the putpose to build the secure group communication among of a group of client users and one server, in this paper, we will present a new password-based group key agreement protocol. Our protocol will meet simplicity, efficiency, and many desired security properties.

Performance study on Gossip-based group key distribution protocal

Group key distribution is faced with two important problems, i.e. reliability and scalability, to support security multicast for large and dynamic groups. With group member increasing, traditional reliable multicast protocol can not deal with them fully. Gossip-based group key distribution idea for wide-area dissemination was provided. It is based on an gossip-based loss recovery control mechanism. It can provide a probabilistic reliable guarantee for a information dissemination to reach every group member, which can achieve scalability and reliability. To achieve full reliability, three layers protocol model in group key distribution was provided. One is best effect layer, which provides unreliable dissemination. Other is gossip-based loss recovery layer, which provides probabilistic reliable guarantee. Last is vsync-based layer, which provide deterministic loss recovery. We integrate probabilistic loss recovery method with deterministic one. The model possess scalability that probabilistic method has and full reliability prosthesis by vsync-based. To evaluate the effectiveness of gossip technique in scalable and reliable multicast protocols. We have compared gossip protocol with other reliable multicast protocols. Experimental result shows that gossip protocol has better scalability than other.

Identity Based Group Key Agreement from Bilinear Pairing

We present a provably secure authenticated tree based key agreement scheme for multicast. There is a wide variety of applications that can benefit from using our scheme, e. g. , pay-Tv, teleconferencing, software updates. Compared with the previous published schemes, our scheme provides group member authentication without introducing additional mechanism. Future, we give the security proof of our scheme under the random oracle model.

A Layer-Cluster Key Agreement Protocol for Ad Hoc Networks

Mobile ad hoc networks create additional challenges for implementing the group key establishment due to resource constraints on nodes and dynamic changes on topology. The nodes in mobile ad hoc networks are usually low power devices that run on battery power. As a result, the costs of the node resources should be minimized when constructing a group key agreement protocol so that the battery life could be prolonged. To achieve this goal, in this paper we propose a security efficient group key agreement protocol based on Burmester-Desmedt （BD） scheme and layer-cluster group model, referred to as LCKM-BD, which is appropriate for large mobile ad hoe networks. In the layer-cluster group model, BD scheme is employed to establish group key, which can not only meet security demands of mobile ad hoc networks but also improve executing performance. Finally, the proposed protocol LCKM-BD are compared with BD, TGDH （tree-based group Diffe-Hellman）, and GDH （group Diffie-Hellman） group key agreement protocols. The analysis results show that our protocol can significantly decrease both the computational overhead and communication costs with respect to these comparable protocols.

Security Analysis of Broadcaster Group Key Exchange Protocols

Group key exchange protocols are basic protocols to provide privacy and integrity in secure group communication. This paper discusses the security of one type of group key exchange protocols and defines the kind of protocols as broadcaster group protocols. It points out two attacks on this kind of protocols. The first attack can be avoided by using fresh values in each action during one session of the group protocol. The second attack should be related with concrete application. It also proposes a dynamic key agreement protocol as an example of solutions at the last part of the paper.

针对动态群组及应用的扩展非对称群密钥协商协议(英文)

Group Key Agreement(GKA)is a cryptographic primitive allowing two or more entities to negotiate a shared session key over public networks.In existing GKA models,it is an open problem to construct a one-round multi-party GKA protocol.Wu et al.recently proposed the concept of asymmetric group key agreement(ASGKA)and realized a one-round ASGKA protocol,which affirmatively answers the above open problem in a relaxed way.However,the ASGKA protocol only applies to static groups.To fill this gap,this paper proposes an extended ASGKA protocol based on the Wu et al.protocol.The extension allows any member to join and leave at any point,provided that the resulting group size is not greater than n.To validate the proposal,extensive experiments are performed and the experimental results show that our protocol is more effective than a plain realization of the Wu et al.protocol for dynamic groups.The extended protocol is also more efficient than the up-to-date dynamic GKA protocol in terms of communication and computation.

通用可组合符号化分析群组密钥协商协议(英文)

Canetti and Herzog have already proposed universally composable symbolic analysis(UCSA) to analyze mutual authentication and key exchange protocols. However,they do not analyze group key exchange protocol. Therefore,this paper explores an approach to analyze group key exchange protocols,which realize automation and guarantee the soundness of cryptography. Considered that there exist many kinds of group key exchange protocols and the participants’ number of each protocol is arbitrary. So this paper takes the case of Burmester-Desmedt(BD) protocol with three participants against passive adversary(3-BD-Passive) . In a nutshell,our works lay the root for analyzing group key exchange protocols automatically without sacrificing soundness of cryptography.

Minimum Exact Cover Problem of Group Key Distribution

Secure group communications are restrained by the number of the group size, number of changes and their distribution, all existing works do not meet the commands of applications with large group size and high dynamic members. In this paper, minimum exact cover problem for group key distribution （GMECP） is presented, and a heuristic solution is testified. Then an algorithm of batch rekeying with renewing cost tending to zero is illustrated, which can process any large number of change requests with best security guaranteed. Efficiency analysis and simulation test show that the achievement can improve the efficiency of any tree-based group key management.

Scalable protocol for cross-domain group password-based authenticated key exchange

Cross-domain password-based authenticated key exchange （PAKE） protocols have been studied for many years. However, these protocols are mainly focusing on multi-participant within a single domain in an open network environment. This paper proposes a novel approach for designing a cross-domain group PAKE protocol, that primarily handles with the setting of multi-participant in the multi- domain. Moreover, our protocol is proved secure against active adversary in the Real-or-Random （ROR） model. In our protocol, no interaction occurs between any two domain authentication servers. They are regarded as ephemeral certificate authorities （CAs） to certify key materials that participants might subsequently use to exchange and agree on group session key. We further justify the computational complexity and measure the average computation time of our protocol. To the best of our knowledge, this is the first work to analyze and discuss a provably secure multi-participant cross-domain group PAKE protocol.

An Improved ID-Based Group Key Agreement Protocol

ID-based constant-round group key agreement protocols are efficient in both computation and communication, but previous protocols did not provide valid message authentication. An improvement based on attack analysis is proposed in this paper. The improved method takes full advantage of the data transmitted at various stages of the protocol. By guaranteeing the freshness of authentication messages, the authenticity of the generator of authentication messages, and the completeness of the authenticator, the improved protocol can resist various passive and active attacks. The forward secrecy of the improved protocol is proved under a Katz-Yung （KY） model. Compared with existing methods, the improved protocol is more effective and applicable.

A dynamic,secure,and efficient group key agreement protocol

The key challenge of dynamic peer communication is how to realize secure and efficient group key manage-ment.A two rounds key agreement protocol for dynamic peer group(DPG)is proposed in this paper.The protocol,which was obtained by combining the ElGamal encryption scheme with the ElGamal signature scheme,is efficient and simple.The protocol is proven secure against passive attack by using indistinguishable method.Moreover,both perfect forward secrecy(PFS)and key independence(KI)were achieved.Because the protocol is based on the broadcast channel,it is also suitable for key agreement in wireless communications,especially in ad-hoc networks.

nPAKE^+:A Tree-Based Group Password-Authenticated Key Exchange Protocol Using Different Passwords

Although two-party password-authenticated key exchange （PAKE） protocols have been intensively studied in recent years, group PAKE protocols have received little attention. In this paper, we propose a tree-based group PAKE protocol - nPAKE^＋ protocol under the setting where each party shares an independent password with a trusted server. The nPAKE^＋ protocol is a novel combination of the hierarchical key tree structure and the password-based Diffie-Hellman exchange, and hence it achieves substantial gain in computation efficiency. In particular, the computation cost for each client in our protocol is only O（log n）. Additionally, the hierarchical feature of nPAKE^＋ enables every subgroup to obtain its own subgroup key in the end. We also prove the security of our protocol under the random oracle model and the ideal cipher model.

Authenticated Group Key Agreement Protocol Based on Twist Conjugacy Problem in Near-Rings

Nowadays some promising authenticated group key agreement protocols are constructed on braid groups, dynamic groups, pairings and bilinear pairings. Hence the non-abelian structure has attracted cryptographers to construct public-key cryptographic protocols. In this article, we propose a new authenticated group key agreement protocol which works in non-abelian near-rings. We have proved that our protocol meets the security attributes under the assumption that the twist conjugacy search problem（TCSP） is hard in near-ring.

A Dynamic ID-Based Authenticated Group Key Exchange Protocol without Pairings

So far, most of the proposed group key exchange （GKE） protocols do not consider the attack when the adversary reveals the parties＇ ephemeral private keys without their long-term private keys, so these GKE protocols are insecure on this attack. In this paper, for resisting above attack, we propose a dynamic authenticated group key exchange （AGKE） protocol in the ID-based setting. Different from previous ID-based protocols, our protocol does not utilize bilinear pairings, which makes it more efficient. At last, we analyze the security of the protocol in the cCK （enhanced Canetti-Krawczyk） security model.

Role of magpie in bird community formation in secondary forest

We analyzed a bird community in a secondary forest and the results show that the magpie was one of the key groups in the secondary forest.The key group is identified based on the nests used by other birds at a rate of 25%-40.17%.The size of the community is different and the number of these key groups is not certain.