Threshold Password-Authenticated Key Exchange

In most password-authenticated key exchange systems there is a single server storing password verification data. To provide some resilience against server compromise, this data typically takes the form of a one-way function of the password (and possibly a salt, or other public values) rather than the password itself. However, if the server is compromised, this password verification data can be used to perform an off-line dictionary attack on the user's password. In this paper we propose an efficient password-authenticated key exchange system involving a set of servers with known public keys, in which a certain threshold of servers must participate in the authentication of a user, and in which the compromise of any fewer than that threshold of servers does not allow an attacker to perform an off-line dictionary attack. We prove our system is secure in the random oracle model under the Decision Diffie-Hellman assumption against an attacker that may eavesdrop on, insert, delete, or modify messages between the user and servers, and that compromises fewer than that threshold of servers.     

HEAP: A packet authentication scheme for mobile ad hoc networks

In mobile ad hoc networks (MANETs) and wireless sensor networks (WSNs), it is easy to launch various sophisticated attacks such as wormhole, man-in-the-middle and denial of service (DoS), or to impersonate another node. To combat such attacks from outsider nodes, we study packet authentication in wireless networks and propose a hop-by-hop, efficient authentication protocol, called HEAP. HEAP authenticates packets at every hop by using a modified HMAC-based algorithm along with two keys and drops any packets that originate from outsiders. HEAP can be used with multicast, unicast or broadcast applications. We ran several simulations to compare HEAP with existing authentication schemes, such as TESLA, LHAP and Lu and Pooch’s algorithm. We measured metrics such as latency, throughput, packet delivery ratio, CPU and memory utilization and show that HEAP performs very well compared to other schemes while guarding against outsider attacks.     

An improved remote password authentication scheme with smart card

This paper analyzes the security performance of a latest proposed remote two-factor user authentication scheme and proposes an improved scheme based on the dynamic ID to avoid the attacks it suffers. Besides this, in our proposed scheme the password is no longer involved in the calculation of verification phase which makes our scheme more secure and costs less than the old one. At last we analyze the performance of our proposed scheme to prove it provides mutual authentication between the user and the server. Moreover, it also resists password guessing attack, server and user masquerade attack and replay attack effectively.     

抗DoS攻击的多用户传感器网络广播认证方案

在vBNN-IBS签名基础上提出了一种抗DoS攻击的多用户传感器网络广播认证方案DDA-MBAS,利用散列运算及用户信息进行虚假数据过滤。与现有的多用户传感器网络广播认证方案相比,DDA-MBAS在抵抗节点妥协攻击、主动攻击的基础上,以较低的能耗过滤虚假消息并有效地限制了妥协用户发起的DoS攻击及共谋攻击的安全威胁。     

移动自组网地址配置问题的研究

MANET（Mobile Ad hoc Network）中没有一个永久的中心机构，其网络拓扑结构不断变化，所以必须有一种能够对网络主机地址动态自配置和管理的协议。给出了在MANET中动态地址自配置与管理的方法，不同方案的特点及适应情况，最后对目前Ad hoc网络地址配置研究进行总结和展望。     

Invincible AODV to detect black hole and gray hole attacks in mobile ad hoc networks

Today's communication world is majorly driven by mobile nodes that demand wireless systems for their data relay. One such network is mobile ad hoc network, which is a purely wireless network with which communication is feasible instantly without any aid of preexisting infrastructure; due to this magnificent feature, it has a wide variety of applications. Mobile ad hoc network hinges on cooperative nature of the mobile nodes for relaying data. But at the same time, nodes relaying data for others may compromise, leading to various security attacks. Two main security attacks that drastically bring down the performance of mobile ad hoc network are black hole and gray hole attacks. In this paper, we propose 2 versions of invincible Ad hoc On‐Demand Distance Vector protocol to detect black hole and gray hole nodes that have bypassed preventive mechanism during route discovery process. First is the basic version, which is based on node‐to‐node frame check sequence tracking mechanism, and second is the enhanced version, which is based on signed frame check sequence tracking mechanism. They create a deterrent environment addressing all kinds of black and gray hole attacks. They also provide reliable data transmission to all the nonmalicious nodes in the network by using end‐to‐end authentication mechanism. Simulation results show better performance in packet delivery ratio when compared with other contemporary solutions while addressing all kinds of black and gray hole attacks. It shows significant improvement in end‐to‐end delay and normalized routing load over Ad hoc On‐Demand Distance Vector under black hole or gray hole attacks and also shows better throughput and packet delivery ratio than the existing solution.     

Design of a user anonymous password authentication scheme without smart card

Recently, Jiang et al. and He et al. independently found security problems in Chen et al.'s remote user authentication scheme for non‐tamper‐proof storage devices like Universal Serial Bus stick and proposed improvements. Nonetheless, we detect that the schemes proposed by Jiang et al. and He et al. overlook a user's privacy. We also observe that Jiang et al.'s scheme is vulnerable to insider attack and denial of service attacks and lacks forward secrecy. We point out that the password changing facility in He et al.'s scheme is equivalent to undergoing registration, whereas in Jiang et al.'s scheme, it is unsuitable. Moreover, the login phase of both the schemes is incapable to prevent the use of wrong password leading to the computation of an unworkable login request. Therefore, we design a new scheme with user anonymity to surmount the identified weaknesses. Without adding much in communication/computational cost, our scheme provides more security characteristics and keeps the merits of the original schemes. As compared with its predecessor schemes, the proposed scheme stands out as a more apt user authentication method for common storage devices. We have also presented a formal proof of security of the proposed scheme based on the logic proposed by Burrows, Abadi and Needham (BAN logic). Copyright © 2014 John Wiley & Sons, Ltd.     

Multifold node authentication in mobile ad hoc networks

An ad hoc network is a collection of nodes that do not need to rely on a predefined infrastructure to keep the network connected. Nodes communicate amongst each other using wireless radios and operate by following a peer‐to‐peer network model. In this article, we propose a multifold node authentication approach for protecting mobile ad hoc networks. The security requirements for protecting data link and network layers are identified and the design criteria for creating secure ad hoc networks using multiple authentication protocols are analysed. Such protocols, which are based on zero‐knowledge and challenge‐response techniques, are presented through proofs and simulation results. Copyright © 2007 John Wiley & Sons, Ltd.     

Threshold cryptography in mobile ad hoc networks under minimal topology and setup assumptions

Mobile Ad Hoc Networks (MANET), due to their lack of physical infrastructures or centralized online authorities, pose a number of security challenges to a protocol designer. In particular, several typical application scenarios demand the design of protocols that cannot base their security on the existence of trusted parties or setup information, but rather need to leverage uniquely on assumptions limiting the corrupting power of the adversaries. This naturally defines security design and analysis paradigms similar to those of the threshold cryptography area, where it is typically assumed that an adversary can corrupt up to a limited amount of entities or resources. Therefore a secure realization of primitives from threshold cryptography in MANET promises to be applicable to several MANET protocols. However, directly applying known threshold cryptography solutions for wired network into MANETs faces serious challenges. In particular, we noted a major design difficulty due to the lack of full network connectivity that significantly constrained the network topology assumptions under which a MANET threshold signature scheme can be proved secure. In this paper we formalize, investigate and present a new MANET threshold signature scheme that is secure under significantly improved topology and setup assumptions. Surprisingly, we break through an apparent barrier due to well-known results from the distributed computing area.     

A study of a routing attack in OLSR‐based mobile ad hoc networks

A mobile ad hoc network (MANET) is a collection of mobile nodes which are able to communicate with each other without relying on predefined infrastructures or central administration. Due to their flexibilities and easy deployment, MANET can be applied in situation where network infrastructures are not available. However, due to their unique characteristics such as open medium and the lack of central administration, they are much more vulnerable to malicious attacks than a conventional infrastructured wireless network. MANET employs routing to provide connectivity for mobile nodes that are not within direct wireless transmission range. Existing routing protocols in MANET assume a trusted and cooperative environment. However, in hostile environment, mobile nodes are susceptible to various kinds of routing attacks. In this paper, we show that an OLSR MANET node is prone to be isolated by malicious attack called Node Isolation attack. After analysing the attack in detail, we present a technique to mitigate the impact of the attack and improve the performance of the network when the attack is launched. The results of our implementations illustrate that the proposed solution can mitigate the attack efficiently. Copyright © 2007 John Wiley & Sons, Ltd.     

基于CSP方法的移动自组织网络认证协议TAM的分析与改进

针对移动自组织网络认证协议应对安全威胁、满足安全目标的有效性问题,提出了采用基于通信顺序进程（CSP, communicating sequential process）和模型检测的协议分析方法,对移动自组织网络的代表性认证协议TAM进行分析、建模、检验并改进。首先采用CSP方法对TAM中参与者的通信行为建立模型、给出了安全目标的安全规范;然后利用模型检测工具FDR验证了TAM的CSP进程,结果表明TAM不满足认证性和机密性安全规范;最后对TAM进行了改进并检验,结果表明改进后的TAM满足安全目标,实验表明与TAM相比,改进的TAM在合理的簇规模情况下增加可接受的额外开销。     

无可信中心的门限追踪ad hoc网络匿名认证

为解决ad hoc网络中的匿名认证问题,将民主签名与无中心的秘密分享方案相结合,提出一种无可信中心的门限追踪ad hoc网络匿名认证方案。方案的无中心性、自组织性很好地满足了ad hoc网络的特征,从而解决了传统网络中匿名认证方案由于需要可信中心而不适合ad hoc网络的问题;方案中认证者的匿名性、可追踪性和完备性(不可冒充性)满足了匿名认证的安全需求。     

Defending against wormhole attacks in mobile ad hoc networks

In ad hoc networks, malicious nodes can deploy wormhole attacks to fabricate a false scenario on the proximity relationship among mobile nodes. A classification of the attacks according to the format of the wormholes is proposed. This forms a basis to identify the detection capability of various approaches. An analysis shows that earlier approaches focus on the prevention of wormholes among neighbors that trust each other. As a more generic approach, we present an end‐to‐end scheme that can detect wormholes on a multi‐hop route. Only the trust between the source and the destination is assumed. The mechanism uses geographic information to detect anomalies in neighbor relations and node movements. To reduce the computation and storage overhead, we present a scheme called cell‐based open tunnel avoidance (COTA) to manage the information. COTA requires a constant space for every node on the path and the computation overhead increases linearly to the number of detection packets. We prove that the savings do not deteriorate the detection capability. Various schemes to control communication overhead are studied. The simulation and experiments on real devices show that the proposed mechanism can be combined with existent routing protocols to defend against wormhole attacks. Copyright © 2006 John Wiley & Sons, Ltd.     

Friend-assisted intrusion detection and response mechanisms for mobile ad hoc networks

Nowadays, a commonly used wireless network (i.e., Wi-Fi) operates with the aid of a fixed infrastructure (i.e., an access point) to facilitate communication between nodes. The need for such a fixed supporting infrastructure limits the adaptability and usability of the wireless network, especially in situations where the deployment of such an infrastructure is impractical. Recent advancements in computer network introduced a new wireless network, known as a mobile ad hoc network (MANET), to overcome the limitations. Often referred as a peer to peer network, the network does not have any fixed topology, and through its multi hop routing facility, each node can function as a router, thus communication between nodes becomes available without the need of a supporting fixed router or an access point. However, these useful facilities come with big challenges, particularly with respect to providing security. A comprehensive analysis of attacks and existing security measures suggested that MANET are not immune to a colluding blackmail because such a network comprises autonomous and anonymous nodes. This paper addresses MANET security issues by proposing a novel intrusion detection system based upon a friendship concept, which could be used to complement existing prevention mechanisms that have been proposed to secure MANETs. Results obtained from the experiments proved that the proposed concepts are capable of minimising the problem currently faced in MANET intrusion detection system (IDS). Through a friendship mechanism, the problems of false accusations and false alarms caused by blackmail attackers in intrusion detection and response mechanisms can be eliminated.     

Improvement of robust smart‐card‐based password authentication scheme

Smart‐card‐based password authentication scheme is one of the commonly used mechanisms to prevent unauthorized service and resource access and to remove the potential security threats over the insecure networks and has been investigated extensively in the last decade. Recently, Chen et al. proposed a smart‐card‐based password authentication scheme and claimed that the scheme can withstand offline password guessing attacks even if the information stored in the smart card is extracted by the adversary. However, we observe that the scheme of Chen et al. is insecure against offline password guessing attacks in this case. To remedy this security problem, we propose an improved authentication protocol, which inherits the merits of the scheme of Chen et al. and is free from the security flaw of their scheme. Compared with the previous schemes, our improved scheme provides more security guarantees while keeping efficiency. Copyright © 2013 John Wiley & Sons, Ltd.     

Defending against cache consistency attacks in wireless ad hoc networks

Caching techniques can be used to reduce bandwidth consumption and data access delay in wireless ad hoc networks. When cache is used, the issue of cache consistency must be addressed, and maintaining strong cache consistency is desired in some strategic scenarios (e.g., battlefields). In these situations, the invalidation-based approach is preferred due to its low overhead. However, this approach may suffer from some security attacks. For example, malicious nodes (also called intruders) may drop, insert or modify invalidation messages to mislead receivers to use stale data or unnecessarily invalidate data that are still valid. In this paper, we first propose to employ the Invalidation Report (IR) based cache invalidation strategy to prevent intruders from dropping or modifying invalidation messages. Although digital signatures can be used to protect IRs, this has significantly high overhead in terms of computational and bandwidth overhead. To address this problem, we further propose a family of randomized grouping-based schemes for intrusion detection, damage recovery and intruder identification. Extensive analysis and simulations are performed to evaluate the proposed schemes. The results show that our solution can achieve a satisfactory level of security with low overhead.     

Securing Threshold Cryptosystems against Chosen Ciphertext Attack

For the most compelling applications of threshold cryptosystems, security against chosen cipher text attack is a requirement. However, prior to the results presented here, there appeared to be no practical threshold cryptosystems in the literature that were provably chosen ciphertext secure, even in the idealized random oracle model. The contribution of this paper is to present two very practical threshold cryptosystems, and to prove that they are secure against chosen ciphertext attack in the random oracle model. Not only are these protocols computationally very efficient, but they are also non-interactive, which means they can be easily run over an asynchronous communication network. Received November 2000 and revised September 2001 Online publication 11 March 2002     

Performance evaluation of mobile ad hoc networks under flooding‐based attacks

A mobile ad hoc network (MANET) is an open wireless network that comprises a set of mobile, decentralized, and self‐organized nodes. Its properties render its environment susceptible to different types of attacks, which can paralyze the mobile nodes in MANET. A particularly dangerous type of attack is run primarily under flooding bogus packet mechanisms, such as hello floods, routing table overflows, exploitation of node penalizing schemes, and resource consumption attack (RCA). Flooding‐based attacks impose severe effects because they are intended to consume MANET resources, such as bandwidth, node memory, and battery power. Therefore, identifying such effects facilitates the development of countermeasures against the intrusions. In this paper, we introduce a simulation‐based study on the effects of RCA on MANET. Qual Net v5.0.2 is used to examine the severity of the effects on MANET performance metrics in terms of throughput, end‐to‐end delay, energy consumption, and routing overhead. The effects of RCA are also monitored under two combinations of four factors: we first vary the number of attackers and attackers' positions, and then modify the attackers' radio range and flooding rate. We also examine the effect of flooding mechanism on the energy consumed by resource consumption attackers. Copyright © 2013 John Wiley & Sons, Ltd.     

一种电力线网络上防御潜在攻击的鲁棒性消息传递机制

网络结构上的信息传递(Message Passing, MP)机制是理解大型网络结构,实现网络节点属性预测的重要工具。然而,在电力线通信网络中,无法在终端和链路上部署复杂的身份识别验证的计算模块,导致无法建立可信的电力线通信网络MP机制,从而无法杜绝潜在攻击者的恶意对抗攻击行为,例如恶意更改电表数据、恶意隐藏终端故障等。为此,以电力节点匿名为动机,将电力节点位置隐藏至高斯噪声中,从而使攻击者无法定位具体的目标节点,抵制潜在的攻击行为。首先证明了节点定位定理,给出了图信息在傅里叶域中传递的数学模型,从而展示主流MP模型(图神经网络)定位节点的具体量化指标;然后设计了一个从高斯噪声中生成节点位置的生成器,实现节点匿名;最后设计了一个对抗生成网络,用来实现精确的电力线通信网络建模。实验表明,即使完全隐藏电力线中节点的位置,通过端到端训练,依然可以实现精确的MP,从而构建更加可信的电力线通信网络理解机制。