一种新的基于椭圆曲线密码体制的 Ad hoc组密钥管理方案

在安全的组通信中,组密钥管理是最关键的问题.论文首先分析了组密钥管理的现状和存在的问题,然后基于椭圆曲线密码体制,针对Ad hoc网络提出了一种安全有效的分布式组密钥管理方案,并对其正确性和安全性进行了证明,由椭圆曲线离散对数困难问题保证协议的安全.针对Ad hoc网络节点随时加入或退出组的特点,提出了有效的组密钥更新方案,实现了组密钥的前向保密与后向保密.与其他组密钥管理方案相比,本方案更加注重组成员的公平性,没有固定的成员结构,并且还具有轮数少、存储开销、通信开销小等特点,适合于在Ad hoc网络环境中使用.     

适合ad hoc网络无需安全信道的密钥管理方案

密钥管理问题是构建ad hoc安全网络系统首要解决的关键问题之一.针对ad hoc网络特点,提出了一个无需安全信道的门限密钥管理方案.该方案中,可信中心的功能由局部注册中心和分布式密钥生成中心共同实现,避免了单点失效问题;通过门限技术,网络内部成员相互协作分布式地生成系统密钥;利用基于双线性对的公钥体制实现了用户和分布式密钥生成中心的双向认证;通过对用户私钥信息进行盲签名防止攻击者获取私钥信息,从而可以在公开信道上安全传输.分析表明该方案达到了第Ⅲ级信任,具有良好的容错性,并能抵御网络中的主动和被动攻击,在满足ad hoc网络安全需求的情况下,极大地降低了计算和存储开销.     

基于椭圆曲线密码组合公钥的ad hoc密钥管理方案

Ad Hoc网络是一种独具特色的网络,作为一种新型的无线,多跳、无中心分布式控制网络,它无需网络基础设施,具有很强的自组织性,鲁棒性.抗毁性和容易构建的特点,其安全问题一直是研究的热点和难点.文中提出了一种改进的基于椭圆曲线密码组合公嘲的ad hoc密钥管理方案.与原方案相比,除了保持快捷地计算出节点的公私钥对、扩展性好、无需证书等特性外,新方案进一步提高了ad hoc网络的安全性,避免了单点失败.     

适于ad hoc网络安全通信的新签密算法

首先提出了一个基于身份的新签密算法,并对其安全性和效率进行了分析及证明;结果表明,该算法在随机预言机模型下是可证明安全的,而且与已有基于身份的签密算法相比,其计算量和传输代价小,特别适合用于ad hoc网络的密钥管理、安全路由等通信安全协议.最后,以ad hoc网络分布式门限密钥管理中各服务节点所拥有的系统密钥份额的更新为例,说明了将新签密算法用于ad hoc网络安全协议的方法及其意义.     

基于簇的ad hoc网络密钥管理方案

将自认证公钥的概念和组合公钥的思想相结合,为ad hoc网络提出了一种新的门限密钥分发方案,在此基础上,和"簇"的组网方式结合,提出一种完整的密钥管理方案.该方案公钥自身具有认证功能,不需要证书管理,密钥分发过程简单,消除了IBE(identity-based encryption)方案中存在的密钥托管问题.方案能够灵活地适应ad hoc网络动态拓扑性,适用于各种规模的网络.理论和仿真分析表明,该方案计算量和通信量都比较小,与PKI、IBE方案相比,具有更高的安全性和实用性.     

Ad_hoc网络动态密钥管理

阐述了当前ad　hoc网络中有关认证和密钥管理的研究概况,特别论述了SecurePebblenets方法中密钥管理节点的生成,对节点加入和退出处理进行更详细分析,并补充了节点变化对簇的影响,对于ad　hoc网络密钥管理的研究具有一定参考价值。     

一种新的适于Ad hoc网可认证密钥协商协议

提出一种新的适于Ad hoc网可认证密钥协商协议。基于签密技术。在同一逻辑步内同时实现了认证和加密功能,提高了密钥协商效率;基于身份的公钥密码系统,降低了建立和管理公钥基础设施的代价;应用椭圆曲线上双线性对,使得该协议能以短的密钥和小的计算量实现同等安全要求。与已有密钥协商协议相比,新协议计算和传输量小,带宽要求低,安全性高,适合能源和带宽受限的Ad hoc网络。     

移动ad hoc网络预分配非对称密钥管理方案

为了降低移动ad hoc网络非对称密钥管理中的通信开销,基于组合公钥思想,将ElGamal方案与预分配密钥方式相结合,提出一种基于身份的预分配非对称密钥管理方案(PAKMS)。该方案通过私钥生成中心为节点预分配主密钥子集及基于时间获得节点密钥更新的方式,从方法上降低了移动ad hoc网络非对称密钥管理中的通信开销;私钥生成中心为节点预分配主密钥子集的方式也使节点在网络运行阶段不再依赖私钥生成中心为节点分配和更新密钥。由此,弱化了基于身份密钥管理中存在的私钥托管问题对网络安全的影响。与典型方案对比分析表明,该方案在提供节点密钥更新服务的情况下能够有效降低网络通信开销。此外,对方案的安全性进行了详细证明。     

利用容错学习问题构造基于身份的全同态加密体制简

基于容错学习问题构造的一类全同态加密体制在云计算安全领域具有重要的潜在应用价值,但同时普遍存在着公钥尺寸较大的缺陷,严重影响其身份认证与密钥管理的效率。将基于身份加密的思想与基于容错学习问题的全同态加密相结合,提出一种基于身份的全同态加密体制,能够有效克服公钥尺寸对于全同态加密应用效率的影响。在随机喻示模型下,体制的安全性归约到容错学习问题难解性和陷门单向函数单向性,并包含严格的安全性证明。     

基于ECC的可公开验证的非交互式密钥共享方案

提出一种基于椭圆曲线加密的非交互式零知识证明协议,并基于该证明协议提出一个可公开验证的密钥共享方案.在该方案中,密钥和密钥份额被嵌入椭圆曲线的点上,任何人均可对密钥和密钥份额进行验证,只有合法参与者集合可恢复出密钥,但无法知道密钥的具体内容;这样有效阻止了攻击者窃取密钥,也防止了数据的误发和成员之间的欺诈,更有利于密钥的复制与更新.     

An efficient heterogeneous key management approach for secure multicast communications in ad hoc networks

In a mobile wireless ad hoc network, mobile nodes cooperate to form a network without using any infrastructure such as access points or base stations. Instead, the mobile nodes forward packets for each other, allowing communication among nodes outside wireless transmission range. As the use of wireless networks increases, security in this domain becomes a very real concern. One fundamental aspect of providing confidentiality and authentication is key distribution. While public-key encryption has provided these properties historically, ad hoc networks are resource constrained and benefit from symmetric key encryption. In this paper, we propose a new key management mechanism to support secure group multicast communications in ad hoc networks. The scheme proposes a dynamic construction of hierarchical clusters based on a novel density function adapted to frequent topology changes. The presented mechanism ensures a fast and efficient key management with respect to the sequential 1 to n multicast service.     

A heterogeneous‐network aided public‐key management scheme for mobile ad hoc networks

A mobile ad hoc network does not require fixed infrastructure to construct connections among nodes. Due to the particular characteristics of mobile ad hoc networks, most existing secure protocols in wired networks do not meet the security requirements for mobile ad hoc networks. Most secure protocols in mobile ad hoc networks, such as secure routing, key agreement and secure group communication protocols, assume that all nodes must have pre‐shared a secret, or pre‐obtained public‐key certificates before joining the network. However, this assumption has a practical weakness for some emergency applications, because some nodes without pre‐obtained certificates will be unable to join the network. In this paper, a heterogeneous‐network aided public‐key management scheme for mobile ad hoc networks is proposed to remedy this weakness. Several heterogeneous networks (such as satellite, unmanned aerial vehicle, or cellular networks) provide wider service areas and ubiquitous connectivity. We adopt these wide‐covered heterogeneous networks to design a secure certificate distribution scheme that allows a mobile node without a pre‐obtained certificate to instantly get a certificate using the communication channel constructed by these wide‐covered heterogeneous networks. Therefore, this scheme enhances the security infrastructure of public key management for mobile ad hoc networks. Copyright © 2006 John Wiley & Sons, Ltd.     

Privacy-preserving attribute-based encryption scheme on ideal lattices

Based on the small key size and high encryption efficiency on ideal lattices,a privacy-preserving attribute-based encryption scheme on ideal lattices was proposed,which could support flexible access policies and privacy protection for the users.In the scheme,a semi-hidden policy was introduced to protect the users’ privacy.Thus,the sensitive values of user’s attributes are hidden to prevent from revealing to any third parties.In addition,the extended Shamir secret-sharing schemes was used to construct the access tree structure which can support “and” “or” and “threshold” operations of attributes with a high flexibility.Besides,the scheme was proved to be secure against chosen plaintext attack under the standard mode.Compared to the existing related schemes,the scheme can yield significant performance benefits,especially the size of system public/secret keys,users’ secret key and ciphertext.It is more effective in the large scale distributed environment.     

An identity attribute–based encryption using elliptic curve digital signature for patient health record maintenance

Providing security to the data that stored in personal health record (PHR) is an emerging and critical task in recent years. For this purpose, some of the encryption and key generation techniques are developed in the traditional works. But it has the drawbacks such as lacks in access control policies, reduced security, and ineffective. So this work implemented the efficient techniques, namely, elliptic curve Diffie‐Hellman for the secret key generation and identity attribute–based encryption for improving the security of the cloud data. Initially, the cloud user can request the patient's data to the PHR admin, and then they can generate the secret by using the elliptic curve Diffie‐Hellman algorithm. The key that used for encryption and decryption is generated by using the identity attribute–based encryption technique. Then, the access control is provided to the users based on their roles. The requested data are encrypted by applying the advanced encryption standard technique. After that, the elliptic curve digital signature algorithm is used to generate the digital signature for the encrypted data. Furthermore, it is verified with the user's digital signature; if it matches, the data can be accessed by the user with the help of advanced encryption standard decryption mechanism. Finally, the authenticated user can able to access the patient's data from PHR. In experiments, the performance of the proposed encryption and key generation technique is evaluated and compared with the existing techniques for proving the effectiveness of the implemented system.     

A hybrid chaotic system and cyclic elliptic curve for image encryption

Recently, several image encryption schemes based on chaotic maps have been proposed. Nevertheless, most of them hinder the system performance, security, and suffer from the small key space problem. This paper presents an efficient hybrid image encryption scheme based on a cyclic elliptic curve and chaotic system that overcomes these disadvantages. The new scheme generates an initial keystream based on chaotic system and an external secret key of 256-bit in a feedback manner. Then, the generated keystream are mixed with key sequences derived from the cyclic elliptic curve points. Thorough encryption performance and security analysis ascertains efficacy of the proposed encryption scheme.     

TIDS: threshold and identity-based security scheme for wireless ad hoc networks

As various applications of wireless ad hoc network have been proposed, security has received increasing attentions as one of the critical research challenges. In this paper, we consider the security issues at network layer, wherein routing and packet forwarding are the main operations. We propose a novel efficient security scheme in order to provide various security characteristics, such as authentication, confidentiality, integrity and non-repudiation for wireless ad hoc networks. In our scheme, we deploy the recently developed concepts of identity-based signcryption and threshold secret sharing. We describe our proposed security solution in context of dynamic source routing (DSR) protocol. Without any assumption of pre-fixed trust relationship between nodes, the ad hoc network works in a self-organizing way to provide key generation and key management services using threshold secret sharing algorithm, which effectively solves the problem of single point of failure in the traditional public-key infrastructure (PKI) supported system. The identity-based signcryption mechanism is applied here not only to provide end-to-end authenticity and confidentiality in a single step, but also to save network bandwidth and computational power of wireless nodes. Moreover, one-way hash chain is used to protect hop-by-hop transmission.     

Securing the Communication in Private Heterogeneous Mobile Ad hoc Networks

Mobile ad hoc networking has been a hot research topic for a decade or so, and many paradigms have been making use of it. One of these paradigms is the Personal Networks (PN). It is an emerging concept where the user’s personal devices form a virtual network which is secure and private, and reacts to changing environment and context intelligently. A fundamental property of the PN is that personal devices form private multi-hop clusters in an ad hoc manner whenever they come across each other. To this end, this paper presents a pair-wise key based scheme for forming secured private clusters in mobile ad hoc networks. The solution tackles the problem of node authentication combined with traffic encryption in relatively small ad hoc networks using proactive neighbour discovery and authentication. Additionally, the paper proves the feasibility of this solution by means of prototyping and experimental performance analysis.     

Privacy preserving friend discovery cross domain scheme using re-encryption in mobile social networks

In order to guarantee the users’ privacy in the process of making friends in the mobile social networks,a new scheme of proxy re-encryption privacy protection in the cross-domain environment was introduced.The scheme employed the cross-domain multi-authority to sharing secret keys,so as to realize the access and shave of the cross-domain users data.And the secret keys of users’ attributes were re-encrypted,based on the technology of the proxy re-encryption and attribute encryption,to achieve the friends matching under the conditions of extending the access policy.Meanwhile,in purpose of enhancing the privacy of users’ data,the technology which contained the separation of users’ privacy ciphertext and secret keys was adopted.Based on that,problems in the existing system such as user data’s inability to be shared cross-cloud,less matching during the process of making friends and users’ inability to make friends when offline had been addressed.Security and experimental analysis show that this scheme can achieve chosen plaintext attack (CPA) security,ensure the privacy of friend discovery,and that is more effective than existing solutions.     

Dynamic asymmetric group key agreement for ad hoc networks

A group key agreement protocol allows a set of users to establish a common symmetric key via open networks. Dynamic asymmetric group key agreement means that a dynamic set of users form a temporary group and negotiate to share a public encryption key, so that anyone can send message securely and efficiently to the temporary group. Users can join or leave the group efficiently without triggering a completely new key agreement protocol, which will greatly benefit the users in ad hoc networks. We describe a generic construction of dynamic asymmetric group key agreement by combining a conventional authenticated group key agreement, a public key encryption and a multi-signature. Then we give out an instance with constant rounds of interactions and constant transmission cost for each participant.