In an ad-hoc network, intermediate nodes on a communication path are expected to forward packets ... more In an ad-hoc network, intermediate nodes on a communication path are expected to forward packets of other nodes so that the mobile nodes can communicate beyond their wireless transmission range. However, because wireless mobile nodes are usually constrained by limited power and computation resources, a selfish node may be unwilling to spend its resources in forwarding packets which are not of its direct interest, even though it expects other nodes to forward its packets to the destination. It has been shown that the presence of such selfish nodes degrades the overall performance of a non-cooperative ad hoc network. To address this problem, we propose a secure and objective reputation-based incentive (SORI) scheme to encourage packet forwarding and discipline selfish behavior. Different from the existing schemes, under our approach, the reputation of a node is quantified by objective measures, and the propagation of reputation is efficiently secured by a one-way-hash-chain-based authentication scheme. Armed with the reputation-based mechanism, we design a punishment scheme to penalize selfish nodes. The experimental results show that the proposed scheme can successfully identify selfish nodes and punish them accordingly.
How to protect location privacy of mobile users is an important issue in ubiquitous computing. Ho... more How to protect location privacy of mobile users is an important issue in ubiquitous computing. However, location privacy protection is particularly challenging: on one hand, the administration requires all legitimate users to provide identity information in order to grant them permission to use its wireless service; on the other hand, mobile users would prefer not to expose any information that could enable anyone, including the administration, to get some clue regarding their whereabouts; mobile users would like to have complete personal control of their location privacy. To address this issue, we propose an authorized-anonymous-ID-based scheme; this scheme effectively eliminates the need for a trusted server or administration, which is assumed in the previous work. Our key weapon is a cryptographic technique called blind signature, which is used to generate an authorized anonymous ID that replaces the real ID of an authorized mobile device. With authorized anonymous IDs, we design an architecture capable of achieving complete personal control over location privacy while maintaining the authentication function required by the administration.
In an ad-hoc network, intermediate nodes on a communication path are expected to forward packets ... more In an ad-hoc network, intermediate nodes on a communication path are expected to forward packets of other nodes so that the mobile nodes can communicate beyond their wireless transmission range. However, because wireless mobile nodes are usually constrained by limited power and computation resources, a selfish node may be unwilling to spend its resources in forwarding packets which are not of its direct interest, even though it expects other nodes to forward its packets to the destination. It has been shown that the presence of such selfish nodes degrades the overall performance of a non-cooperative ad hoc network. To address this problem, we propose a secure and objective reputation-based incentive (SORI) scheme to encourage packet forwarding and discipline selfish behavior. Different from the existing schemes, under our approach, the reputation of a node is quantified by objective measures, and the propagation of reputation is efficiently secured by a one-way-hash-chain-based authentication scheme. Armed with the reputation-based mechanism, we design a punishment scheme to penalize selfish nodes. The experimental results show that the proposed scheme can successfully identify selfish nodes and punish them accordingly.
How to protect location privacy of mobile users is an important issue in ubiquitous computing. Ho... more How to protect location privacy of mobile users is an important issue in ubiquitous computing. However, location privacy protection is particularly challenging: on one hand, the administration requires all legitimate users to provide identity information in order to grant them permission to use its wireless service; on the other hand, mobile users would prefer not to expose any information that could enable anyone, including the administration, to get some clue regarding their whereabouts; mobile users would like to have complete personal control of their location privacy. To address this issue, we propose an authorized-anonymous-ID-based scheme; this scheme effectively eliminates the need for a trusted server or administration, which is assumed in the previous work. Our key weapon is a cryptographic technique called blind signature, which is used to generate an authorized anonymous ID that replaces the real ID of an authorized mobile device. With authorized anonymous IDs, we design an architecture capable of achieving complete personal control over location privacy while maintaining the authentication function required by the administration.
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