It is only after expensive computations necessary for

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natures.” It is only after expensive computations necessary for verification, can the unfortunate receivers realize that the signature is invalid. In general, MANET devices will need to employ several key distribution schemes for different types of security associations, for different network layers. In other words, every mobile device may be assigned many sets of secrets, used for different purposes. However, as we shall see in Section 4.3, it is desirable to ensure that some secrets assigned to a mobile device are protected even from the user of the device. We shall also see that in such scenarios, it is very much desirable to keep the computational overhead for operations performed with such protected secrets to very low levels. 4.3. Protection of Secrets The computers taking part in any network can be broadly classified into 1) network hosts; and 2) routers. In conventional networks like the Internet, computers have very well defined tasks. Network hosts are clients or servers Copyright © 2010. World Scientific Publishing Company. All rights reserved. May not be reproduced in any form without permission from the publisher, except fair uses permitted under U.S. or applicable copyright law. EBSCO Publishing : eBook Collection (EBSCOhost) - printed on 2/16/2016 3:46 AM via CGC-GROUP OF COLLEGES (GHARUAN) AN: 340572 ; Beyah, Raheem, Corbett, Cherita, McNair, Janise.; Security in Ad Hoc and Sensor Networks Account: ns224671
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50 M. Ramkumar that exchange application data. The broad purpose of a host is to satisfy the needs of the user employing the host. On the other hand, routers are computers that are entrusted with the task of routing packets between net- work hosts. Routers thus perform the “selfless” task of serving other hosts. Internet routers are typically managed by organizations with substantial infrastructural backing, and are thus implicitly trusted by all hosts. In contrast, in ad hoc networks, most computers will simultaneously perform the roles of network hosts and routers. It is thus instructive to see every mobile device that takes part in ad hoc networks as consisting of two agents 15 - a user agent, and a network agent. The “selfish” user agent works only on behalf of the owner of the mobile device to send application data to other mobile computers, and thus carries out tasks performed by a host (a client or a server) in conventional networks. The “selfless” network agent works for the entire network to route packets between user agents, and thus performs the task performed by routers in conventional networks. For this purpose network agents are expected to strictly comply with co-operative routing protocols. Ideally, users with selfish interests should not be able to 1) impersonate the network agent to send misleading routing information; or 2) modify the tasks entrusted to the network agent. Thus the network agent tasks should (ideally) be carried out inside the confines of a tamper-responsive d trusted boundary.
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  • Spring '12
  • Kushal Kanwar
  • Public key infrastructure, ........., Public-key cryptography, Pretty Good Privacy

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