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Wireless metropolitan area sharing networks (WMSNs) are wide-area wireless networks with nodes owned and managed by independent wireless Internet service providers (WISPs). To support seamless roaming in emerging WMSNs, in this paper, we propose a localized and distributed authentication and billing architecture that aims at enabling efficient and privacy-preserving mutual authentication between mobile users (MUs) and WISPs. User anonymity and identity privacy can be protected, even in the presence of collusion between WISPs and a roaming broker (RB), which is considered to be the strongest user privacy protection. An efficient billing architecture is introduced and performed in the same stage of roaming, where U-tokens are defined and can be purchased by MUs from an RB as authentication credentials for the MUs to access the wireless network. The WISPs, thus, can cash the collected U-tokens in the RB for payment. We show that the proposed authentication and billing architecture can support localized inter-WISP authentication through the divisible blind signature scheme and a local witness strategy. A detailed analysis on a number of performance metrics, such as computation time and power consumption, is given to validate the performance of the proposed architectures. Index Terms--Billing, partially blind signature, privacy protection, roaming, wireless metropolitan area sharing networks (WMSNs).

The characterization of a video segment by a digital signature is a fundamental task in video processing. It is necessary for video indexing and retrieval, copyright protection, and other tasks. Semantic video signatures are those that are based on high-level content information rather than on low-level features of the video stream. The major advantage of such signatures is that they are highly invariant to nearly all types of distortion. A major semantic feature of a video is the appearance of specific persons in specific video frames. Because of the great amount of research that has been performed on the subject of face detection and recognition, the extraction of such information is generally tractable, or will be in the near future. We have developed a method that uses the pre-extracted output of face detection and recognition to perform fast semantic query-by-example retrieval of video segments. We also give the results of the experimental evaluation of our method on a database of real video. One advantage of our approach is that the evaluation of similarity is convolution-based, and is thus resistant to perturbations in the signature and independent of the exact boundaries of the query segment. Index Terms--Face recognition, multimedia databases, query-by-example, video retrieval.

Signatures were considered an important tool for authenticating the identity of human beings. So, signature verification was one of the biggest uses for that. We proposed an algorithmic approach for the verification of handwritten signatures by applying some statistical methods. The research work was based on the collection of set of signatures from which an average signature was obtained based on our algorithm and then taking decision of acceptance after analyzing the correlation in between the sample signature and the average signature. Key words: Signatures, authenticating, statistical methods, acceptance, analyzing, correlation, sample signature and average signature, INTRODUCTION Signatures are composed of special characters and flourishes and therefore most of the time they can be unreadable. Also intrapersonal variations and the differences make it necessary to analyze [...]