Wireless sensor networking is an emerging technology, which potentially supports many emerging applications for both civilian and military purposes, ranging from environmental monitoring to battlefield surveillance. However, since sensor nodes are inexpensive devices, which could be easily compromised and controlled by an adversary, the compromised nodes could report false sensed results and degrade the reliability of the whole network. Therefore, how to identify these compromised nodes in a wireless sensor network is a very important security issue. To solve this problem, we propose an efficient algorithm, called AICN, to logically identify the compromised nodes in an efficient and effective way. Based on the network reliability estimation (NRE), we also present its enhanced version to further improve the efficiency.

Addressing security and privacy issues is a prerequisite for a market-ready vehicular communication network. Although recent related studies have already addressed most of these issues, few of them have taken scalability issues into consideration. When the traffic density becomes larger, a vehicle cannot verify all signatures of the messages sent by its neighbors in a timely manner, which results in message loss. Communication overhead as another issue has also not been well addressed in previously reported studies. To deal with these issues, this paper introduces a novel RSU-aided messages authentication scheme, called RAISE. With RAISE, roadside units (RSUs) are responsible for verifying the authenticity of the messages sent from vehicles and for notifying the results back to vehicles. In addition, our scheme adopts the k-anonymity approach to protect user identity privacy, where an adversary cannot associate a message with a particular vehicle. Extensive simulations are conducted to verify the proposed scheme, which demonstrates that RAISE yields much better performance than any of the previously reported counterparts in terms of message loss ratio and delay.

With the adoption of state-of-the-art telecommunication technologies for sensing and collecting traffic related information, Vehicular Sensor Networks (VSNs) have emerged as a new application scenario that is envisioned to revolutionize the human driving experiences and traffic flow control systems. To avoid any possible malicious attack and resource abuse, employing a digital signature scheme is widely recognized as the most effective approach for VSNs to achieve authentication, integrity, and validity. However, when the number of signatures received by a Roadside Unit (RSU) becomes large, a scalability problem emerges immediately, where the RSU could be difficult to sequentially verify each received signature within 300 ms interval according to the current Dedicated Short Range Communications (DSRC) broadcast protocol. We introduce an efficient batch signature verification scheme for communications between vehicles and RSUs (or termed vehicle- to-Infrastructure (V2I) communications), in which an RSU can verify multiple received signatures at the same time such that the total verification time can be dramatically reduced. We demonstrate that the proposed scheme can achieve conditional privacy preservation that is essential in VSNs, where each message launched by a vehicle is mapped to a distinct pseudo identity, while a trust authority can always retrieve the real identity of a vehicle from any pseudo identity. With the proposed scheme, since identity-based cryptography is employed in generating private keys for pseudo identities, certificates are not needed and thus transmission overhead can be significantly reduced.

To enhance the overall performance of a mobile ad hoc network (MANET), people have tried to solve the issue of node selfishness, which has sparked a surge of research interests in credit-based incentive protocols. The core idea of credit-based incentive is to provide incentives for selfish nodes to faithfully forward packets in a MANET. Recently, several credit-based incentive protocols have been proposed. However, the fairness issue in those reported credit-based incentive protocols has never been well addressed yet. Without the fairness guarantees, the whole network still cannot reach its optimum cooperative status. Therefore, in this paper, aiming at fairness, we first define the fairness principle for credit-based incentive protocol, and then present a novel fair incentive protocol (FIP) for MANETs.

As an emerging application scenario of wireless technologies, vehicular communications have been initiated not only for enhancing the transportation safety and driving experiences, but also for a new commercial market of on-board Internet services. Due to extraordinarily high mobility of vehicles in a vehicular network, frequent handover requests will be a norm, which initiates the demand for an effective and fast authentication scheme that can maintain the service continuity in presence of the frequent handover events. However, previously reported authentication schemes, although with minimized handover latency and packet loss rate, may disclose the location information of the mobile user to the third party, which will seriously violate the location privacy of the user. In this paper, we propose a location privacy preserving authentication scheme based on blind signature in the elliptic curve domain. The scheme cannot only provide fast authentication, but also guarantee the security and location anonymity to the public. To analyze the proposed scheme, a theoretical traceability analysis is conducted, which shows that the probability of tracing an vehicle's route is negligibly small. We will also examine the authentication speed of the scheme, and show that the scheme can satisfy seamless handover for fast moving vehicles.

Abstract Vehicular ad hoc networks (VANETs) are gaining growing interest from both industry and academia. The primitive objective of VANETs is to enhance the road safety for public transportation systems through dedicated short range communications (DSRC) protocol. In addition to the powerful radios and abundant spectrums, DSRC also paves the way for VANETs to support numerous emerging Internet‐related applications. In this paper, we introduce a promising commercial application which allows each vehicle to purchase file/data through a roadside unit (RSU). Due to the high mobility of vehicles, the contact period between an RSU and a vehicle could be insufficient to download the complete file. Thus, in the proposed file purchasing systems, once a vehicle in the process of downloading a file leaves the transmission range of the RSU, its neighboring vehicles with a piece of the file can cooperatively help to complete the file transfer via vehicle‐to‐vehicle (V2V) communications. Such a commercial file purchasing system can obviously initiate a new application scenario; however, it cannot be put into practice unless the security issues, such as the user privacy, incentives for inter‐vehicle cooperation, and the copyright protection for∼the file content, are well addressed. In order to deal with these security issues, we develop a secure framework for the file purchasing system in VANETs. Performance evaluation will be conducted to verify the proposed scheme. Copyright © 2008 John Wiley & Sons, Ltd.

In this paper, we propose a Timed Efficient and Secure Vehicular Communication (TSVC) scheme with privacy preservation, which aims at minimizing the packet overhead in terms of signature overhead and signature verification latency without compromising the security and privacy requirements. Compared with currently existing public key based packet authentication schemes for security and privacy, the communication and computation overhead of TSVC can be significantly reduced due to the short message authentication code (MAC) tag attached in each packet for the packet authentication, by which only a fast hash operation is required to verify each packet. Simulation results demonstrate that TSVC maintains acceptable packet latency with much less packet overhead, while significantly reducing the packet loss ratio compared with that of the existing public key infrastructure (PKI) based schemes, especially when the road traffic is heavy.

In this paper, we propose a new TESLA (timed efficient stream loss-tolerant authentication) based secure vehicular communication (TSVC) protocol with privacy preserving, aiming to achieve less communication overhead without compromising the security and privacy requirements. With TSVC, the communication overhead can be significantly reduced due to the message authentication code (MAC) tag attached in each packet and only a fast hash operation is required to verify each packet. Simulation results show that TSVC maintains acceptable message latency with much smaller packet size while significantly reducing the message loss ratio compared with that by the existing PKI-based protocols especially when the traffic is denser.

Nowadays, wireless personal devices, such as cell phones and Personal Data Assistants (PDAs), have gradually taken an important part of our daily lives. With two-factor authentication, the wireless personal devices can be further promoted to more security demanding and mission-critical applications, such as e-commerce, home surveillance, and medical monitoring, etc. Facility access is one of applications that have demonstrated a tremendous market potential for replacing the conventional physical key approach. In this paper, we present a novel keyless facility access control system by using wireless personal devices, where the devices serve as a second authentication factor to assure security. The proposed system is not only cost-efficient, but also capable of mitigating security threats existing in the traditional key control system. Furthermore, the proposed authentication protocol is featured in two different authentication processes for the first time and subsequent accesses by using a one-time authentication mechanism based on one-way hash chain while considering the resource constraints of the wireless personal devices and E-lock. Finally, a role-based access control (RBAC) system is adopted to reduce the complexity of key maintenance.