基于RLWE的生物特征认证密钥交换协议

在后量子密码学中,针对密钥交换协议存在口令容易丢失以及难以实现相互认证的安全缺陷,提出了一个新的基于环上误差学习的生物特征认证密钥交换协议。该协议根据环上误差学习问题构造的密码体制具有密钥及密文尺寸短、运行效率高等优势,并采用生物特征和口令作为长期密钥,同时通过Peikert式错误协调机制从各自的环元素中协调出随机均匀的会话密钥,实现了服务器对客户的显式认证。性能分析结果表明,该方案可抵抗用户假冒攻击,安全属性更高,提高了通信效率。     

一个前向安全的基于口令认证的三方密钥交换协议

目前,文献中提出的基于口令认证的密钥交换协议,很多都是针对两方的情形设计的,即通信双方为客户与服务器,它们通过一个预先共享的口令来进行认证的密钥交换.随着现代通信环境的快速变化,需要能为任意客户间构建一个端到端的安全信道,这种应用的情形与那些文献中所考虑的有很大区别.针对这种情形,文中提出了一个可证前向安全的基于口令认证的三方密钥交换协议,使通信双方在认证服务器的帮助下能相互进行认证并建立一个会话密钥.与前人提出的基于口令认证的三方密钥交换协议相比,该协议在计算代价和通信代价上都较有效,因而更适用于资源受限的环境.此协议的安全性是在口令型的选择基Gap Diffie-Hellman问题难解的假设前提下在随机谕示模型下证明的.     

标准模型下高效的三方口令认证密钥交换协议

三方口令认证密钥交换协议允许两个分别与服务器共享不同口令的用户在服务器的协助下建立共享的会话密钥,从而实现了用户间端到端的安全通信.现阶段,多数的三方口令认证密钥交换协议都是在随机预言模型下可证明安全的.但在实际应用中,利用哈希函数对随机预言函数进行实例化的时候会给随机预言模型下可证明安全的协议带来安全隐患,甚至将导致协议不安全.以基于ElGamal加密的平滑投射哈希函数为工具,在共同参考串模型下设计了一种高效的三方口令认证密钥交换协议,并且在标准模型下基于DDH假设证明了协议的安全性.与已有的同类协议相比,该协议在同等的安全假设下具有更高的计算效率和通信效率,因此更适用于大规模的端到端通信环境.     

改进的三方口令认证密钥交换协议

基于三方的口令认证密钥交换（3PAKE）协议是客户通过与可信服务器共享一个口令验证元,在两客户进行通信时通过此可信服务器进行会话密钥的建立与共享,从而进行通信。首先对李文敏等人提出的协议进行安全性分析,发现该协议易受离线字典攻击和服务器泄露攻击。提出了一个改进协议,该协议能够提供双向认证、会话密钥机密性和前向安全性,能够有效抵抗多种攻击,包括离线字典攻击和服务器泄露攻击。     

基于理想格的用户匿名口令认证密钥协商协议

基于标准格的密钥协商协议具有较长的密钥长度和较高的密文扩张率,且格的表示方式需要较大的空间,而理想格具有密钥长度短和运行效率高等优点。因此,结合环上误差学习问题,提出基于理想格的用户匿名口令认证密钥协商协议。使用低熵的口令,通过服务器实现相互认证和共享会话密钥,以避免在身份认证过程中用户长期密钥的存储安全受到威胁。分析结果表明,与传统的2PAKE和3PAKE协议相比,该协议具有较高的效率和较短的密钥长度,能够抵抗量子攻击,适用于大规模网络通信。     

简单的三方口令密钥交换协议

基于口令认证的三方密钥交换协议（3PAKE）是通信双方在认证服务器的帮助下能在公开非安全的信道上协商并建立一个共享会话密钥。虽然目前有不少该方面的研究,但多数后来被证实易受攻击。本文给合以往的研究,提出一个不需服务器公钥体系的简单的基于口令认证的三方密钥交换协议。本文的协议不仅能抵抗各种攻击,而且计算成本和通信成本都比较低。     

基于RSA的网关口令认证密钥交换协议

网关口令认证密钥交换协议是一个三方协议,使得用户和网关在服务器的协助下建立起一个安全的会话密钥,从而实现用户和网关之间的安全通信.已有的网关口令认证密钥交换协议都是基于Diffie-Hellman密钥交换设计的.利用张木想所设计的PEKEP协议,提出了基于RSA体制的可证明安全的网关口令认证密钥交换协议.在随机预言模型...     

基于不同口令认证的跨域组密钥协议

近年来关于基于口令认证的密钥交换协议(PAKE)进行了广泛的研究,基于口令认证的组密钥交换协议已成为安全协议研究的焦点问题.Byun等人也先后提出了基于不同口令认证的跨域环境下端到端的两个客户之间的PAKE(C2C-PAKE)密钥交换协议.然而在实际应用中,往往还需要在多个客户或客户组之间建立安全的通信信道.因此,提出了基于不同口令认证的跨域组间密钥交换协议,该协议将Zhiguo Wan等人所提出的nPAKE+协议扩展到了两个域,实现了两个域中的客户组在域服务器的协助下,建立域间共享的组会话密钥的过程,并给出了安全分析和执行效率的代价分析.     

基于混沌映射的用户匿名三方口令认证密钥协商协议

在基于混沌的三方口令认证密钥协商协议中,用户通过低熵的口令实现相互认证和共享会话密钥,以避免在身份认证过程中公钥基础设施或存储用户长期密钥的安全威胁。通过分析Lee提出的基于混沌映射的口令认证密钥协商协议,发现其协议不能进行口令变更,而且仅适用于用户和服务器之间的两方通信。为了改进此方案,提出两个基于切比雪夫混沌映射的用户匿名三方口令认证密钥协商协议,包括基于时钟同步的密钥协商方案和基于随机数的密钥协商方案。其中基于时钟同步的用户匿名三方口令认证密钥协商协议通信量少,基于随机数的用户匿名三方口令认证密钥协商协议更容易实现。两个方案的优点是用户仅选择一个简单的口令进行相互认证和密钥协商,服务器不需要再保护用户口令表,避免了口令相关的攻击,而且在相互认证过程中用户使用临时身份和哈希函数,实现用户匿名性,在增强协议安全性的同时,减少了通信过程中消息的数量,提高了协议的执行效率,具有完美前向安全,并用BAN逻辑证明了其安全性。     

基于椭圆曲线的加密密钥交换协议

加密密钥交换协议(EKE)的目的是利用安全性低的口令协商安全性高的密钥,进而利用密钥对以后的通信进行加密或身份认证,从而实现安全通信.基于验证元的EKE是针对服务器泄露攻击问题提出的.本文基于椭圆曲线密码系统的特点,给出了一个基于验证元的3EKE,该协议中,服务器通过口令实现对用户的认证;协议能够抵抗服务器泄露等攻击,...     

具有强匿名性的网关口令认证密钥交换协议

网关口令认证密钥交换协议允许用户和网关在服务器的协助下建立起一个共享的会话密钥,其中用户和服务器之间的认证通过低熵的口令来完成.已有的网关口令认证密钥交换协议对用户的匿名性研究不足.该文基于Diffie-Hellman密钥交换提出了具有强匿名性的网关口令认证密钥交换协议,并且在随机预言模型下基于标准的DDH假设证明了协议的安全性.新协议可以抵抗不可检测在线字典攻击并且计算效率高,安全性和计算效率都优于已有的同类协议.     

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。     

基于口令的客户端/服务器认证协议

身份认证是建立客户端和服务器之间安全会话的前提条件。Kim和Chung提出了一种双方的双向认证方案,其以较小的计算量得到了学者们的关注。但经分析发现,该方案并不安全：无法抵抗离线口令猜测攻击和无限次在线口令猜测攻击,也不能防止服务器伪装攻击。为了解决这些安全隐患,利用非对称Rabin密码体制提出了一种改进的方案,并基于BAN逻辑对方案的正确性进行了严格验证。最后还分析了新方案的安全性和性能。     

Universally composable anonymous password authenticated key exchange

Anonymous password authenticated key exchange (APAKE) is an important cryptographic primitive, through which a client holding a password can establish a session key with a server both authentically and anonymously. Although the server is guaranteed that the client in communication is from a pre-determined group, but the client’s actual identity is protected. Because of their convenience, APAKE protocols have been widely studied and applied to the privacy protection research. However, all existing APAKE protocols are handled in stand-alone models and do not adequately settle the problem of protocol composition, which is a practical issue for protocol implementation. In this paper, we overcome this issue by formulating and realizing an ideal functionality for APAKE within the well-known universal composability (UC) framework, which thus guarantees security under the protocol composition operations. Our formulation captures the essential security requirements of APAKE such as off-line dictionary attack resistance, client anonymity and explicit mutual authentication. Moreover, it addresses the arbitrary probabilistic distribution of passwords. The construction of our protocol, which utilizes SPHF-friendly commitments and CCA2-secure encryption schemes, can be instantiated and proven secure in the standard model, i.e., without random oracle heuristics.     

An efficient and practical threshold gateway-oriented password-authenticated key exchange protocol in the standard model

With the assistance of an authentication server, a gateway-oriented password-authenticated key exchange (GPAKE) protocol can establish a common session key shared between a client and a gateway. Unfortunately, a GPAKE protocol becomes totally insecure if an adversary can compromise the authentication server and steal the passwords of the clients. In order to provide resilience against adversaries who can hack into the authentication server, we propose a threshold GPAKE protocol and then present its security proof in the standard model based on the hardness of the decisional Diffie-Hellman (DDH) problem. In our proposal, the password is shared among n authentication servers and is secure unless the adversary corrupts more than t+1 servers. Our protocol requires n > 3t servers to work. Compared with existing threshold PAKE protocols, our protocol maintains both stronger security and greater efficiency.     

标准模型下隐私保护的多因素密钥交换协议

多因素认证密钥交换协议融合多种不同的认证因素来实现强安全的身份认证和访问控制,在具有高级别安全应用需求的移动泛在服务中具有巨大的应用潜力.现阶段多因素协议的研究成果还不丰富,并且已有协议都是在随机预言模型下可证明安全的.以两方口令认证密钥交换协议、鲁棒的模糊提取器以及签名方案为基本组件提出了一个标准模型下可证明安全的多因素协议.本文的协议中服务器不知道用户的生物模板,因此实现了对生物信息的隐私保护.与已有的随机预言模型下的多因素协议相比,本文的协议在满足更高安全性的同时具有更高的计算效率和通信效率,因此更满足高级别安全的移动泛在服务的应用需求.     

SPP: An anti-phishing single password protocol

Most users have multiple accounts on the Internet where each account is protected by a password. To avoid the headache in remembering and managing a long list of different and unrelated passwords, most users simply use the same password for multiple accounts. Unfortunately, the predominant HTTP basic authentication protocol (even over SSL) makes this common practice remarkably dangerous: an attacker can effectively steal users’ passwords for high-security servers (such as an online banking website) by setting up a malicious server or breaking into a low-security server (such as a high-school alumni website). Furthermore, the HTTP basic authentication protocol is vulnerable to phishing attacks because a client needs to reveal his password to the server that the client wants to login.In this paper, we propose a protocol that allows a client to securely use a single password across multiple servers, and also prevents phishing attacks. Our protocol achieves client authentication without the client revealing his password to the server at any point. Therefore, a compromised server cannot steal a client’s password and replay it to another server.Our protocol is simple, secure, efficient and user-friendly. In terms of simplicity, it only involves three messages. In terms of security, the protocol is secure against the attacks that have been discovered so far including the ones that are difficult to defend, such as the malicious server attacks described above and the recent phishing attacks. Essentially our protocol is an anti-phishing password protocol. In terms of efficiency, each run of our protocol only involves a total of four computations of a one-way hash function. In terms of usability, the protocol requires a user to remember only one password consisting of eight (or more) random characters, and this password can be used for all of his accounts.     

An efficient user authentication and key exchange protocol for mobile client–server environment

Considering the low-power computing capability of mobile devices, the security scheme design is a nontrivial challenge. The identity (ID)-based public-key system with bilinear pairings defined on elliptic curves offers a flexible approach to achieve simplifying the certificate management. In the past, many user authentication schemes with bilinear pairings have been proposed. In 2009, Goriparthi et al. also proposed a new user authentication scheme for mobile client–server environment. However, these schemes do not provide mutual authentication and key exchange between the client and the server that are necessary for mobile wireless networks. In this paper, we present a new user authentication and key exchange protocol using bilinear pairings for mobile client–server environment. As compared with the recently proposed pairing-based user authentication schemes, our protocol provides both mutual authentication and key exchange. Performance analysis is made to show that our presented protocol is well suited for mobile client–server environment. Security analysis is given to demonstrate that our proposed protocol is provably secure against previous attacks.