PoK

Author:Pan Wang,Peng Ning,Douglas S. Reeves

Description:
Anonymity is increasingly important for network applications concerning about censorship and privacy. The ex isting anonymous communication protocols generally system from mixnet and DC net. They either cannot provide provable anonymity or suer from transmission collision. In this paper, we introduce a novel approach which takes advantage of hierarchical ring structure and mix technique. This proposed protocol is collision free and provides provable k
anonymity for both the sender and the recipient, even if a polynomial time adversary can eavesdrop all network trafic and control a fraction of participants. Furthermore, it can hide the sender and the recipient from each other and thus can be used for anonymous ¯le sharing. The analysis shows the proposed protocol is secure against various at tacks. Measurements further demonstrate it is practical.

Author:Qi Dong, Donggang Liu,Peng Ning

Description:
Recent studies have demonstrated that it is possible to per form public key cryptographic operations on the resource constrained sensor platforms. However, the significant resource consumption imposed by public key cryptographic operations makes such mechanisms easy targets of Denial of Service (DoS) attacks. For example, if digital signatures such as ECDSA are used directly for broadcast authenti cation without further protection, an attacker can simply broadcast forged packets and force the receiving nodes to perform a large number of unnecessary signature verifications, eventually exhausting their battery power. This paper studies how to deal with such DoS attacks when signatures are used for broadcast authentication in sensor networks.In particular, this paper presents two filtering techniques,a group based filter and a key chain based filter, to handle DoS attacks against signature verification. Both methods can significantly reduce the number of unnecessary signature verifications that a sensor node hasto perform. The analytical results also show t

Author:Donggang Liu,Peng Ning, An Liu,Cliff Wang,Wenliang Kevin Du

Description:
Many sensor network applications require sensors’ locations to function correctly. Despite the recent advances, location discovery for sensor networks in hostile environments has been mostly overlooked. Most of the existing localization protocols for sensor networks are vulnerable in hostile environments. The security of location discovery can certainly be enhanced by authentication. However, the possible node compromises and the fact that location determination uses certain physical features (e.g., received signal strength) of radio signals make authentication not as effective as in traditional security applications. This paper presents two methods to tolerate malicious attacks against range based location discovery in sensor networks. The first method filters out malicious beacon signals on the basis of the “consistency” among multiple beacon signals, while the second method tolerates malicious beacon signals by adopting an iteratively refined voting scheme. Both methods can survive malicious attacks even if the attacks bypass authentication,provided that the benign beacon signals constitute the majority of the beacon signals. This paper also presents the implementation and experimental evaluation (through both field experiments and simulation) of all the secure and resilient location estimation schemes that can be used on the current generation of sensor platforms (e.g., MICA series of motes), including the techniques proposed in this paper, in a network of MICAz motes. The experimental results demonstrate the effectiveness of the proposed methods, and also give the secure and resilient location estimation scheme most suitalbe for the current generation of sensor networks.