Unformatted text preview: e client now decrypts the first message and retrieves the session key. The secret key is a one-way hash of her password, so a legitimate user will have no trouble doing this. If the user were an imposter, he would not know the correct password and therefore could not decrypt the response from the Kerberos authentication server. Access would be denied and he wouldn’t be able to get the ticket or the session key. The client saves the TGT and session key and erases the password and the one-way hash. This information is erased to reduce the chance of compromise. If an adversary manages to copy the client’s memory, he will only get the TGT and the session key. These are valuable pieces of information, but only during the lifetime of the TGT. After the TGT expires, they will be worthless. The client can now prove her identity to the TGS for the lifetime of the TGT. Previous Table of Contents Next Products | Contact Us | About Us | Privacy | Ad Info | Home Use of this site is subject to certain Terms & Conditions, Copyright © 1996-2000 EarthWeb Inc. All rights reserved. Reproduction whole or in part in any form or medium without express written permission of EarthWeb is prohibited. Read EarthWeb's privacy statement. To access the contents, click the chapter and section titles. Applied Cryptography, Second Edition: Protocols, Algorthms, and Source Code in C (cloth)
Brief Full Advanced Search Search Tips (Publisher: John Wiley & Sons, Inc.) Author(s): Bruce Schneier ISBN: 0471128457 Publication Date: 01/01/96 Search this book:
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----------- Getting Server Tickets
A client has to obtain a separate ticket for each service she wants to use. The TGS grants tickets for individual servers. When a client needs a ticket that she does not already have, she sends a request to the TGS. (In reality, the program would do this automatically, and it would be invisible to the user.) The TGS, upon receiving the request, decrypts the TGT with his secret key. Then he uses the session key included in the TGT to decrypt the authent...
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