改进的双方密钥协商协议

双方认证密钥协商是生成会话密钥的重要手段。分析了赵建杰等于2011年提出的一个可证明安全的双方认证密钥协商协议,指出如果敌手持有原协议的长期私钥,协议是不安全的。提出一种改进的协议,新协议将影响安全性的公开参数保护起来,避免了长期私钥的泄露,并对新协议的安全性和计算量进行了讨论。分析结果表明,新协议在减少计算量的前提下实现了协议双方的安全密钥协商。     

构建无证书的两方认证密钥协商协议

基于无证书的认证密钥协商方案相比基于PKI的方案具有身份管理的简单性,同时相比基于身份的方案具有无密钥托管性。基于可证安全的无证书加密方案提出了一个两方认证密钥协商方案.通过与其他方案在安全性和有效性方面的比较,该方案满足更多的安全属性要求,如完美前向安全性,PKG前向安全性,已知会话相关临时秘密信息安全性和无密钥托管等安全特性,同时具有良好的计算有效性。     

可证明安全的后量子两方口令认证密钥协商协议

口令认证密钥协商可以在客户机和服务器之间建立安全的远程通信,且可以将一个低熵口令放大为一个高熵的会话密钥。然而,随着量子计算技术的快速发展,基于大数分解和离散对数等经典数学难题的PAKA协议面临着严峻的安全挑战。因此,为了构建一个高效安全的后量子PAKA协议,依据改进的Bellare-Pointcheval-Rogaway(BPR)模型,提出了一个基于格的匿名两方PAKA协议,并且使用给出严格的形式化安全证明。性能分析结果表明,该方案与相关的PAKA协议相比,在安全性和执行效率等方面有一定优势,更适用于资源受限的物联网(Internet of Things, IoT)智能移动设备。     

基于身份的增强三方认证密钥协商协议

现有的三方认证密钥协商协议安全性低且计算开销较大,提出一种基于身份的增强三方认证密钥协商协议。新协议在实现密钥协商基本安全属性的同时,利用短签名和时间戳技术进一步提高安全性。分析表明,增强协议能满足现有已知的三方密钥协商安全属性,且仅需两次双线性对运算,计算开销更低。此外,提出更强的抗密钥泄露伪装属性,首次指出陈浩等人以及陈家琪等人方案存在重大缺陷。     

高效的强安全的基于身份认证密钥协商协议

现有的基于身份(ID)认证协议大多在CK模型中被证明是安全的,而CK模型比扩展的CK模型(eCK模型)更弱。基于NAXOS方法,利用双线性对设计了一种新协议,并基于随机预言假设和GBDH假设,在eCK模型中证明了协议的安全性。与其他的基于身份认证协议相比,新协议的计算复杂度和通信复杂度较低;满足主密钥前向安全性和完美前向安全性,并抗密钥泄漏伪装。     

标准模型下可证安全的认证密钥协商协议

提出了一个标准模型下的基于身份认证的密钥协商协议。协议的设计采用了双线性配对的思想,协议的安全性分析,则综合运用了串空间知识以及可证安全中Game证明的方法,给出了严格的证明。协议具有良好的前向安全性和会话密钥无托管性,通过利用显式的身份认证,提高了协议的执行效率。与随机预言模型中的协议相比,在计算和通信效率方面相当。     

一个前向安全的基于签密的密钥协商协议*

安全有效地传递信息是计算机安全通信研究领域的主要目标。借鉴Zheng和张串绒将签密技术运用到密钥协商协议中的思想,利用基于身份的签密方案,提出一种具有前向安全性的密钥协商协议。该协议在具有基于身份的公钥密码体制特点的同时,又拥有签密技术的优点。与已有的方案相比,该密钥协商协议除了具有机密性、认证性、还具有前向安全性的特点。     

一个基于身份的密钥隔离认证密钥协商协议

鉴于目前已有的基于身份的认证密钥协商协议都未考虑后向安全性,结合密钥进化的思想,利用椭圆曲线加法群提出了一个基于身份的密钥隔离认证密钥协商协议.协议去除了双线性对运算,效率比基于双线性对构造的基于身份的协议有较大提高;协议不仅满足目前已知的所有针对认证密钥协商协议的安全性要求,而且还满足后向安全性.     

高效安全的无证书密钥协商方案*

在网络信息安全领域,服务器与客户机之间的密钥协商显得非常必要。无证书公钥密码是为了克服基于身份密码的密钥托管性质提出来的,它结合了传统公钥证书密码体系和基于身份的公钥体系的优点。应用椭圆曲线的配对运算,提出了一个两方的无证书密钥协商协议,其中每一方只需计算一个配对,并证明了它在ECK模型下的安全性。与其他无证书密钥协商协议相比,安全性和效率都更好。     

A novel pairing-free certificateless authenticated key agreement protocol with provable security

Recently, He et al. (Computers and Mathematics with Applications, 2012) proposed an efficient pairing-free certificateless authenticated key agreement (CL-AKA) protocol and claimed their protocol was provably secure in the extended Canetti-Krawczyk (eCK) model. By giving concrete attacks, we indicate that their protocol is not secure in the eCK model. We propose an improved protocol and show our improvement is secure in the eCK model under the gap Diffie-Hellman (GDH) assumption. Furthermore, the proposed protocol is very efficient.     

无双线性对的无证书两方认证密钥协商协议

鉴于双线性对运算复杂度较高,不适用于移动通信环境,提出新的无双线性对的基于无证书的两方认证密钥协商协议。新协议解决了基于身份的公钥密码方案中固有的密钥托管问题,实现了对通信双方的身份认证,采用非双线性对运算,极大地降低了计算开销。通过分析协议的正确性,采用Applied Pi演算对协议进行形式化分析,借助ProVerif工具验证了协议的安全性和认证性。与其他两方密钥协商协议相比,新方案具有更好的安全性和效率。     

An improved identity-based key agreement protocol and its security proof

We revisit the identity-based (ID-based) key agreement protocol due to Ryu et al. The protocol is highly efficient and suitable for real-world applications despite offering no resilience against key-compromise impersonation (K-CI). We show that the protocol is also insecure against reflection attacks. We propose a slight modification to the protocol and prove its security in a widely accepted model.     

两个安全的无证书三方认证密钥协商协议

针对李、贾的两个无证书三方协议,分别构造具体攻击算法证明方案均有安全缺陷,进一步提出了新的三方认证密钥协商协议并进行分析;由于该协议计算效率的局限性,同时在考虑内部人攻击的情况下采用Schnnor签名提出第二个协议。与同类协议相比,两协议均具有安全性优势,满足完美前向安全、已知会话密钥安全、抗密钥泄露伪装安全和抗临时密钥泄露安全等属性,避免了证书管理和密钥托管的缺陷;协议1与2相比,前者通信成本较低并实现了可证安全,后者计算效率更高且抗内部人攻击,均适用于电子商务、手机漫游或电子会议三方交互应用场景。     

Strongly secure identity-based authenticated key agreement protocols in the escrow mode

Escrowable identity-based authenticated key agreement(AKA) protocols are desirable under certain circumstances especially in certain closed groups applications.In this paper,we focus on two-party identitybased AKA schemes in the escrow mode,and present a strongly secure escrowable identity-based AKA protocol which captures all basic desirable security properties including perfect forward secrecy,ephemeral secrets reveal resistance and so on.The protocol is provably secure in the extended Canetti-Krawczyk model,and its security can be reduced to the standard computational bilinear Diffie-Hellman assumption in the random oracle model.Assuming no adversary can obtain the master private key for the escrow mode,our scheme is secure as long as each party has at least one uncompromised secret.Also,we present two strongly secure variants of the protocol,which are computationally more efficient than the original scheme.     

可信计算环境下基于TPM的认证密钥协商协议

基于身份的认证密钥协商协议存在密钥托管、ID管理、ID唯一性和私钥的安全分发等问题,目前的可信计算技术为此提供了很好的解决方案。利用TPM平台中EK和tpmproof唯一性的特点,结合McCullagh-Barreto认证密钥协商协议思想,提出了一个在可信计算环境下基于TPM的认证密钥协商协议,该协议较好地解决了上述基于身份的密钥协商协议所存在的问题。用CK模型对所提协议进行了安全性分析,结果表明该协议具备已知密钥安全性,完善前向保密性及密钥泄露安全性等CK安全模型下相应的安全属性。     

身份基认证密钥协商协议的分析与改进

对三个标准模型下可证明安全的身份基认证密钥协商协议进行了安全属性缺陷分析,在原方案基础上提出了一个安全增强的新方案。新方案满足目前已知的绝大多数安全属性要求,包括已知会话密钥安全性、抗密钥泄露伪装、抗未知密钥共享、无密钥控制以及消息独立性,特别是满足完美前向安全性、PKG前向安全性、已知会话相关临时秘密信息安全性,同时保持了良好的计算效率。     

Provably secure identity-based authenticated key agreement protocols with malicious private key generators

Identity-based authenticated key agreement is a useful cryptographic primitive and has received a lot of attention. The security of an identity-based system relies on a trusted private key generator (PKG) that generates private keys for users. Unfortunately, the assumption of a trusted PKG (or a curious-but-honest PKG) is considered to be too strong in some situations. Therefore, achieving security without such an assumption has been considered in many cryptographic protocols. As a PKG knows the private keys of its users, man-in-the-middle attacks (MIMAs) from a malicious PKG is considered as the strongest attack against a key agreement protocol. Although securing a key agreement process against such attacks is desirable, all existent identity-based key agreement protocols are not secure under such attacks. In this paper, we, for the first time, propose an identity-based authenticated key agreement protocol resisting MIMAs from malicious PKGs that form a tree, which is a commonly used PKG structure for distributing the power of PKGs. Users are registered at a PKG in the tree and each holds a private key generated with all master keys of associated PKGs. This structure is much more efficient, in comparison with other existing schemes such as threshold-based schemes where a user has to register with all PKGs. We present our idea in two protocols. The first protocol is not secure against MIMAs from some kinds of malicious PKGs but holds all other desirable security properties. The second protocol is fully secure against MIMAs. We provide a complete security proof to our protocols.     

A pairing-free identity-based authenticated key agreement protocol with minimal message exchanges

Based on the computational Diffie-Hellman problem, this paper proposes an identity-based authenticated key agreement protocol which removes bilinear pairings. Compared with previous protocols, the new protocol minimizes message exchange time with no extra cost. The protocol provides strong security guarantees including key compromise impersonation resilience, perfect forward secrecy, and master key forward secrecy. A security proof with the modular approach in the modified Bellare-Rogaway model is also provided.