Enhanced Dynamic Authentication Scheme (EDAS)

With non-stop growth in network environments, communication security is necessary. A strong protocol guarantees that users and service providers are secure against many kinds of attacks, such as impersonation and replay attack. Sood et al. proposed an authentication scheme based on dynamic identity to prevent transactions from being intercepted by malicious users. Although they claimed that their scheme has advantages over previous schemes with the same approach, we prove that their scheme is vulnerable to impersonation attack and stolen verification attack, and can be affected by clock synchronization. Therefore we propose a novel authentication scheme to enhance security and overcome limitations existing in Sood’s scheme. Our security analysis shows that our proposed method can efficiently resist known types of attacks. Experimental results also show that the method can be implemented and processed in real-time thus applicable for not only regular computers but also mobile devices.     

A privacy preserving three-factor authentication protocol for e-Health clouds

E-Health clouds are gaining increasing popularity by facilitating the storage and sharing of big data in healthcare. However, such an adoption also brings about a series of challenges, especially, how to ensure the security and privacy of highly sensitive health data. Among them, one of the major issues is authentication, which ensures that sensitive medical data in the cloud are not available to illegal users. Three-factor authentication combining password, smart card and biometrics perfectly matches this requirement by providing high security strength. Recently, Wu et al. proposed a three-factor authentication protocol based on elliptic curve cryptosystem which attempts to fulfill three-factor security and resist various existing attacks, providing many advantages over existing schemes. However, we first show that their scheme is susceptible to user impersonation attack in the registration phase. In addition, their scheme is also vulnerable to offline password guessing attack in the login and password change phase, under the condition that the mobile device is lost or stolen. Furthermore, it fails to provide user revocation when the mobile device is lost or stolen. To remedy these flaws, we put forward a robust three-factor authentication protocol, which not only guards various known attacks, but also provides more desired security properties. We demonstrate that our scheme provides mutual authentication using the Burrows–Abadi–Needham logic.     

An anonymous mobile user authentication protocol using self-certified public keys based on multi-server architectures

As a smart phone becomes a daily necessity, mobile services are springing up. A mobile user should be authenticated and authorized before accessing these mobile services. Generally, mobile user authentication is a method which is used to validate the legitimacy of a mobile login user. As the rapid booming of computer networks, multi-server architecture has been pervasive in many network environments. Much recent research has been focused on proposing password-based remote user authentication protocols using smart cards for multi-server environments. To protect the privacy of users, many dynamic identity based remote user authentication protocols were proposed. In 2009, Hsiang and Shih claimed their protocol is efficient, secure, and suitable for the practical application environment. However, Sood et al. pointed out Hsiang et al.’s protocol is susceptible to replay attack, impersonation attack and stolen smart card attack. Moreover, the password change phase of Hsiang et al.’s protocol is incorrect. Thus, Sood et al. proposed an improved protocol claimed to be practical and computationally efficient. Nevertheless, Li et al. found that Sood et al.’s protocol is still vulnerable to leak-of-verifier attack, stolen smart card attack and impersonation attack and consequently proposed an improvement to remove the aforementioned weaknesses. In 2012, Liao et al. proposed a novel pairing-based remote user authentication protocol for multi-server environment, the scheme based on elliptic curve cryptosystem is more secure and efficient. However, through careful analyses, we find that Liao et al.’s protocol is still susceptible to the trace attack. Besides, Liao et al.’s protocol is inefficient since each service server has to update its ID table periodically. In this paper, we propose an improved protocol to solve these weaknesses. By enhancing the security, the improved protocol is well suited for the practical environment.     

A secure and efficient ECC-based user anonymity-preserving session initiation authentication protocol using smart card

The Session Initiation Protocol (SIP) is a signaling communications protocol, which has been chosen for controlling multimedia communication in 3G mobile networks. The proposed authentication in SIP is HTTP digest based authentication. Recently, Tu et al. presented an improvement of Zhang et al.’s smart card-based authenticated key agreement protocol for SIP. Their scheme efficiently resists password guessing attack. However, in this paper, we analyze the security of Tu et al.’s scheme and demonstrate their scheme is still vulnerable to user’s impersonation attack, server spoofing attack and man-in-the middle attack. We aim to propose an efficient improvement on Tu et al.’s scheme to overcome the weaknesses of their scheme, while retaining the original merits of their scheme. Through the rigorous informal and formal security analysis, we show that our scheme is secure against various known attacks including the attacks found in Tu et al.’s scheme. Furthermore, we simulate our scheme for the formal security analysis using the widely-accepted AVISPA (Automated Validation of Internet Security Protocols and Applications) tool and show that our scheme is secure against passive and active attacks including the replay and man-in-the-middle attacks. Additionally, the proposed scheme is comparable in terms of the communication and computational overheads with Tu et al.’s scheme and other related existing schemes.     

An efficient client–client password-based authentication scheme with provable security

Recently, Tso proposed a three-party password-based authenticated key exchange (3PAKE) protocol. This protocol allows two clients to authenticate each other and establish a secure session key through a server over an insecure channel. The main security goals of such protocols are authentication and privacy. However, we show that Tso’s protocol achieves neither authentication goal nor privacy goal. In this paper, we indicate that the privacy and authentication goals of Tso’s protocol will be broken by off-line password guessing attack and impersonation attack, respectively. To overcome the weaknesses, we propose an improved 3PAKE protocol to achieve more security and performance than related protocols. The security of the proposed improved protocol is proved in random oracle model.     

一种更具实用性的移动RFID认证协议

针对Doss协议的不足,提出了一种改进的轻量级移动RFID认证协议。首先使用二次剩余混合随机数加密的方法提高后台服务器识别速度;在阅读器端添加时间戳生成器,抵御阅读器冒充及重放攻击。新协议标签端只采用成本较低的伪随机数生成、模平方以及异或运算,遵循了EPC C1G2标准,且实现了移动RFID环境下的安全认证。理论分析及实验显示了新协议提高了Doss协议后台识别速度,并满足标签和阅读器的匿名性、阅读器隐私、标签前向隐私等安全需求,更有效抵抗已有的各种攻击：重放、冒充、去同步化攻击等。与同类RFID认证协议相比,实用性更佳。     

A secure user anonymity-preserving biometric-based multi-server authenticated key agreement scheme using smart cards

Advancement in communication technology provides a scalable platform for various services, where a remote user can access the server from anywhere without moving from its place. It provides a unique opportunity for online services such that a user does not need to be physically present at the service center. These services adopt authentication and key agreement protocols in order to ensure authorized and secure access to the resources. Most of the authentication schemes proposed in the literature support a single-server environment, where the user has to register with each server. If a user wishes to access multiple application servers, he/she requires to register with each server. The multi-server authentication introduces a scalable platform such that a user can interact with any server using single registration. Recently, Chuang and Chen proposed an efficient multi-server authenticated key agreement scheme based on a user’s password and biometrics (Chuang and Chen, 2014). Their scheme is a lightweight, which requires the computation of only hash functions. In this paper, we first analyze Chuang and Chen’s scheme and then identify that their scheme does not resist stolen smart card attack which causes the user’s impersonation attack and server spoofing attack. We also show that their scheme fails to protect denial-of-service attack. We aim to propose an efficient improvement on Chuang and Chen’s scheme to overcome the weaknesses of their scheme, while also retaining the original merits of their scheme. Through the rigorous informal and formal security analysis, we show that our scheme is secure against various known attacks including the attacks found in Chuang and Chen’s scheme. Furthermore, we simulate our scheme for the formal security verification using the widely-accepted AVISPA (Automated Validation of Internet Security Protocols and Applications) tool and show that our scheme is secure against the replay and man-in-the-middle attacks. In addition, our scheme is comparable in terms of the communication and computational overheads with Chuang and Chen’s scheme and other related existing schemes.     

Elliptic curve cryptography based mutual authentication scheme for session initiation protocol

The Session Initiation Protocol (SIP) is the most widely used signaling protocol for controlling communication on the internet, establishing, maintaining, and terminating the sessions. The services that are enabled by SIP are equally applicable in the world of multimedia communication. Recently, Tsai proposed an efficient nonce-based authentication scheme for SIP. In this paper, we do a cryptanalysis of Tsai’s scheme and show that Tsai’s scheme is vulnerable to the password guessing attack and stolen-verifier attack. Furthermore, Tsai’s scheme does not provide known-key secrecy and perfect forward secrecy. We also propose a novel and secure mutual authentication scheme based on elliptic curve discrete logarithm problem for SIP which is immune to the presented attacks.     

雾计算中基于DQL算法的伪装攻击检测方案

雾计算是一种在云数据中心和物联网（Internet of Things,IoT）设备之间提供分布式计算、存储等服务的技术,它能利用网络边缘进行认证并提供与云交互的方法。雾计算中以传统的安全技术实现用户与雾节点间安全性的方法不够完善,它仍然面对着窃听攻击、伪装攻击等安全威胁,这对检测技术提出了新的挑战。针对这一问题,提出了一种基于DQL（Double Q-learning）算法的雾计算伪装攻击检测方案。该方案借助物理层安全技术中的信道参数,首先在Q-learning算法的基础上处理Q值过度估计问题,获取最佳的伪装攻击测试阈值,然后通过阈值实现了用户与雾节点间的伪装攻击检测。实验结果表明,该算法检测伪装攻击的性能优于传统的Q-learning算法,具有在雾计算安全防护方面的优越性。     

Cryptanalysis and improvement of a robust smart card secured authentication scheme on SIP using elliptic curve cryptography

The session initiation protocol (SIP) has been receiving a lot of attention to provide security in the Voice over IP (VoIP) in Internet and mobility management. Recently, Yeh et al. proposed a smart card-based authentication scheme for SIP using elliptic curve cryptography (ECC). They claimed that their scheme is secure against known security attacks. However, in this paper, we indicate that Yeh et al.’s scheme is vulnerable to off-line password guessing attack, user impersonation attack and server impersonation attack, in the case that the smart card is stolen and the information stored in the smart card is disclosed. As a remedy, we also propose an improved smart card-based authentication scheme which not only conquers the security weaknesses of the related schemes but also provides a reduction in computational cost. The proposed scheme also provides the user anonymity and untraceability, and allows a user to change his/her password without informing the remote server. To show the security of our protocol, we prove its security the random oracle model.     

一种无证书认证密钥协商协议的分析与改进*

研究无证书公钥密码系统中两方认证密钥协商协议问题。对Liu xu的无证书两方认证密钥协商协议进行安全性分析,指出该方案不具有强安全性。该方案不能抵抗密钥泄露伪装攻击和临时私钥泄露攻击。分析了方案不安全的原因,在此基础上提出一个改进的方案来修正Liu xu的方案。因此,设计看似安全的无证书两方认证密钥协商协议并不困难,但要给出协议的安全性证明并不容易。     

A secure and efficient authenticated encryption for electronic payment systems using elliptic curve cryptography

The use of e-payment system for electronic trade is on its way to make daily life more easy and convenient. Contrarily, there are a number of security issues to be addressed, user anonymity and fair exchange have become important concerns along with authentication, confidentiality, integrity and non-repudiation. In a number of existing e-payment schemes, the customer pays for the product before acquiring it. Furthermore, many such schemes require very high computation and communication costs. To address such issues recently Yang et al. proposed an authenticated encryption scheme and an e-payment scheme based on their authenticated encryption. They excluded the need of digital signatures for authentication. Further they claimed their schemes to resist replay, man-in-middle, impersonation and identity theft attack while providing confidentiality, authenticity, integrity and privacy protection. However our analysis exposed that Yang et al.’s both authenticated encryption scheme and e-payment system are vulnerable to impersonation attack. An adversary just having knowledge of public parameters can easily masquerade as a legal user. Furthermore, we proposed improved authenticated encryption and e-payment schemes to overcome weaknesses of Yang et al.’s schemes. We prove the security of our schemes using automated tool ProVerif. The improved schemes are more robust and more lightweight than Yang et al.’s schemes which is evident from security and performance analysis.     

Security analysis and enhancements of an improved authentication for session initiation protocol with provable security

Very recently, Tu et al. proposed an authentication scheme for session initiation protocol using smart card to overcome the security flaws of Zhang et al.’s protocol. They claimed that their protocol is secure against known security attacks. However, in this paper, we indicate that Tu et al.’s protocol is insecure against impersonation attack. We show that an adversary can easily masquerade as a legal server to fool users. As a remedy, we also improve Tu et al.’s protocol without imposing extra computation cost. To show the security of our protocol, we prove its security in the random oracle model.     

基于云PACS系统的DICOM协议安全通信框架

传统的PACS系统存储和维护海量医疗影像数据成本高昂,且经由DICOM协议传输的影像数据容易遭到黑客攻击,造成数据被非法篡取、病人隐私泄露等数据安全性问题。提出一种PACS云服务模型以满足数据存储、维护、安全传输等需求。设计的统一身份认证框架采用基于USB Key强身份认证方案和基于SSL通用身份认证方案两种混合验证模式,经过安全性分析表明,此框架能够保证数据的秘密性、认证性和完整性,并能抵御常见的中间人攻击、重放攻击和字典攻击,有效确保云PACS系统中DICOM协议安全通信。     

一个强口令认证方案的攻击与改进

讨论了于江等新近提出的一个简单高效的基于USB-Key的强口令认证方案(USPA),指出该方案无法实现所声称的抵抗DoS攻击、重放攻击、Stolen-Verifier攻击和服务器仿冒攻击。给出一个改进方案,并对其安全性和效率进行了详细的分析。结果表明,改进方案弥补了USPA的安全缺陷,并且保持了较高的效率,适用于安全需求较高的移动应用环境。     

云计算中基于可转换代理签密的可证安全的认证协议

云用户与公有云之间的双向认证是云计算中用户访问公有云的重要前提.2011年,Juang等首次提出了云计算环境下采用代理签名的认证协议,其优点是用户只需到私有云中注册,然后在私有云的帮助下通过公有云的认证.但是,该方案存在3个缺陷:1)为保护用户的隐私,每次会话都需更新用户公钥;2)当私有云中的许多用户同时登录不同的公有云时,私有云会遭遇网络拥堵;3)用户的私有云与访问的公有云之间需要预先共享秘密.为弥补上述不足,提出了一种保护用户隐私的可证安全的可转换代理签密方案,基于该方案设计了一种一轮云计算认证协议.新方案的优点在于用户向私有云注册后,就能通过公有云的认证,而不需要私有云的帮助,并且它还能保护用户的隐私性、抗抵赖性.协议不需要在每次会话开始前更新用户公钥,同时私有云与访问的公有云之间不再需要预先共享秘密.在随机谕言机模型下证明了新协议的安全性,并且比较说明新协议在效率方面优于Juang等的协议.     

DoS-resistant ID-based password authentication scheme using smart cards

In this paper, we provide a defense mechanism to Kim-Lee-Yoo’s ID-based password authentication scheme, which is vulnerable to impersonation attacks and resource exhaustion attacks. Mutual authentication and communication privacy are regarded as essential requirements in today’s client/server-based architecture; therefore, a lightweight but secure mutual authentication method is introduced in the proposed scheme. Once the mutual authentication is successful, the session key will be established without any further computation. The proposed defense mechanism not only accomplishes the mutual authentication and the session key establishment, but also inherits the security advantages of Kim-Lee-Yoo’s scheme, e.g. it is secure against password guessing attacks and message replay attacks.     

On the security and improvement of a two-factor user authentication scheme in wireless sensor networks

User authentication is a basic security requirement during the deployment of the wireless sensor network (WSN), because it may operate in a rather hostile environment, such as a military battlefield. In 2010, Khan and Alghathbar (KA) found out that Das’s two-factor user authentication scheme for WSNs is vulnerable to the gateway node (GW-node) bypassing attack and the privileged-insider attack. They further presented an improved scheme to overcome the security flaws of Das’s scheme. However, in this paper, we show that KA’s scheme still suffers from the GW-node impersonation attack, the GW-node bypassing attack, and the privileged-insider attack. Hence, to fix the security flaws in KA’s scheme, we propose a new user authentication scheme for WSNs. The security of the user authentication session in the proposed scheme is reduced by the model of Bellare and Rogaway. The security of partial compromise of secrets in the proposed scheme is reduced and analyzed by our adversarial model. Based on the performance evaluation, the overall cost of the proposed scheme is less than that of KA’s scheme. Hence, we believe that the proposed scheme is more suitable for real security applications than KA’s scheme.     

可保证临时秘密泄漏安全的无证书签密方案

为了确保无证书签密方案能实现临时秘密泄漏安全性,提出了一种新的无需对运算的无证书签密方案.新签密方案将用户部分私钥、用户私有秘密和签密临时秘密分别对应到求解3个不同的CDH (computational Diffie-Hellman)问题,并采用散列函数将用户密钥、临时秘密和密文与用户身份绑定.表明了新方案不仅能实现数据的认证性、机密性,还能确保临时秘密泄漏安全性.对比分析结果表明,新方案的安全性更高,计算性能更优.此外,文中还指出文献[3]中签密方案不能抵抗临时秘密泄露攻击.     

普适环境下基于生物加密的认证机制

普适计算的出现对网络通信中的安全和隐私提出了新的挑战,传统的认证技术已经不能满足普适环境的安全需求。提出了一种普适环境中用于完成服务使用者与提供者之间双向认证及密钥建立的机制。该机制高度融合了生物加密技术和Diffie-Hellman密钥交换技术,在不泄露用户隐私的情况完成双向认证。该机制提供了安全的建立密钥的算法,并且通过使用生物加密技术实现了访问控制策略的区别对待。经分析证明,该协议能很好地抵抗各种攻击,尤其是拒绝服务（DoS）攻击。