For kssc irrespective of the value n the

Info icon This preview shows pages 60–62. Sign up to view the full content.

For KSSC, irrespective of the value n the computational overhead for A (to compute K AB ) involves evaluation of tens of hashes. For the MLS scheme, the computational overhead amounts to computing a single hash. Thus for scenarios where low computational overhead is an important requirement, MLS and KSSC are best suited. One-to-many SAs: For certificates based asymmetric schemes, to ver- ify a signature appended by some node C , A will have to verify the pub- lic key certificate of C and then verify the signature of C . For one time signatures, the computational overhead amounts to about 1000-2000 hash function evaluations. Signing is typically twice as expensive as verification in terms of the number of hash function evaluations. 4.1.2. In-network Bandwidth Overhead One-to-one SAs: For CB public key schemes, the in-network bandwidth overhead for establishing a shared secret K AB is for exchanging public key certificates (certificates may be a few thousand bits long) and two encrypted challenges (each 1000 bits long). For ID based schemes (scalable KPSs like Blom’s scheme, KSSC, and “nonscalable” MLS) no bandwidth overhead is required for computing a shared secret. Thus for scenarios where low 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
Image of page 60

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

48 M. Ramkumar bandwidth overhead is an important requirement, MLS and KSSC are best suited. One-to-many SAs: When public key CB schemes are used for signa- tures, the bandwidth overhead is for the appended signature and the public key certificate. When one-time signature scheme is used for this purpose, the signature takes the form of a few tens of hashes. In addition, several hashes from a Merkle tree will need to be revealed to authenticate the OTS commitment. For public key CB schemes the overhead for disseminating and verifying certificates can be amortized for several subsequent signa- tures. However, in OTS schemes where a commitment can be used for only one signature, every signature should be accompanied by several additional hashes for authenticating the commitment. Furthermore, the bandwidth overhead for CB schemes may also be dif- ferent for different network layers. The in-network bandwidth overhead for appended authentication and exchanging certificates is less of a concern for link layer SAs, as certificates need to be broadcast only once for the ben- efit of all neighbors. The overhead for this purpose may also be tolerable for application layer SAs as the certificates need to be relayed only over the path between the end-points. However for network layer SAs, where the certificate of some device has to be sent to possibly all mobiles in the subnet, the overhead can be substantial.
Image of page 61
Image of page 62
This is the end of the preview. Sign up to access the rest of the document.
  • Spring '12
  • Kushal Kanwar
  • Public key infrastructure, ........., Public-key cryptography, Pretty Good Privacy

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern