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Unformatted text preview: ize each other’s voice. Eve still has a possible attack. Imagine her in the middle of Alice and Bob’s conversation. She uses one TSD on the line with Alice and a modified TSD on the line with Bob; in the middle she bridges the two phone calls. Alice tries to go secure. She generates a key as normal, except that Eve is acting as Bob. Eve recovers the key, and using the modified TSD, forces the key she generates with Bob to have the same hash value. This attack may not sound very likely, but the TSD uses a variant of the interlock protocol to prevent it. The TSD generates random numbers using a noise source and a chaotic amplifier with digital feedback. This generates a bit stream, which is fed through a post-whitening filter using the digital signal processor. Despite all of this, the TSD manual does not mention security at all. In fact, it says : AT&ampT makes no warranty that the TSD will prevent cryptanalytic attack on any encrypted transmission by any government agency, its agents, or any third party. Furthermore, AT&ampT makes no warranty that the TSD will prevent any attack on any communication by methods which bypass encryption. 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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----------- Chapter 25 Politics
25.1 National Security Agency (NSA)
The NSA is the National Security Agency (once called “No Such Agency” or “Never Say Anything,” but they’ve been more open recently), the official security body of the U.S. government. President Harry Truman created the agency in 1952 under the Department of Defense, and for many years its very existence was kept secret. The NSA is c...
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