Bharat K. Bhargava

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We present the design, implementation, and evaluation of PROMISE, a novel peer-to-peer media streaming system encompassing the key functions of peer lookup, peer-based aggregated streaming, and dynamic adaptations to network and peer conditions. Particularly, PROMISE is based on a new application level P2P service called <i>CollectCast</i>. CollectCast(More)
Multimedia data secmity is important for multimedia commerce. Previous cryptography studies have focused on text data. The encryption algorithms devdoped to secure text data may not be suitable to multimedia applications becattse of large data sizes and real time constraint. For multimedia applications, light weight encryption algorithms are attractive. We(More)
Privacy is needed in ad hoc networks. An ad hoc on-demand position-based private routing algorithm, called AO2P, is proposed for communication anonymity. Only the position of the destination is exposed in the network for route discovery. To discover routes with the limited routing information, a receiver contention scheme is designed for determining the(More)
Several protocols have been proposed to defend against wormholes in ad hoc networks by adopting positioning devices, synchronized clocks, or directional antennas. In this paper, we propose a mechanism, MDS-VOW, to detect wormholes in a sensor network. MDS-VOW first reconstructs the layout of the sensors using multi-dimensional scaling. To compensate the(More)
In this paper, we study a peer-to-peer media streaming system with the following characteristics: (1) its streaming capacity grows dynamically; (2) peers do not exhibit serverlike behavior; (3) peers are heterogeneous in their bandwidth contribution; and (4) each streaming session may involve multiple supplying peers. Based on these characteristics, we(More)
Checkpointing in a distributed system is essential for recovery to a globally consistent state after failure. In this paper, we propose a solution that benifits from the research in concurrency control, commit protocols, and site recovery algorithms. A number of checkpointing processes, a number of rollback processes, and computations on operational(More)
Providing secure and efficient access to large scale outsourced data is an important component of cloud computing. In this paper, we propose a mechanism to solve this problem in owner-write-users-read applications. We propose to encrypt every data block with a different key so that flexible cryptography-based access control can be achieved. Through the(More)
Mobile systems have limited resources, such as battery life, network bandwidth, storage capacity, and processor performance. These restrictions may be alleviated by computation of f loading: sending heavy computation to resourceful servers and receiving the results from these servers. Many issues related to offloading have been investigated in the past(More)
It is expected that in the near future millions of users will have access to on-line distributed databases through mobile computers. This possibility raises challenging questions regarding the consistency and availability of data. To deal with the frequent, predictable and varying in degree disconnections that occur in a mobile environment, we introduce(More)