Unformatted text preview: rs can be easier to implement in software, because they often avoid time-consuming bit manipulations and they operate on data in computer-sized blocks. On the other hand, stream ciphers can be more suitable for hardware implementation because they can be implemented very efficiently in silicon. These are important considerations. It makes sense for a hardware encryption device on a digital communications channel to encrypt the individual bits as they go by. This is what the device sees. On the other hand, it makes no sense for a software encryption device to encrypt each individual bit separately. There are some specific instances where bit- and byte-wise encryption might be necessary in a computer system—encrypting the link between the keyboard and the CPU, for example—but generally the encryption block should be at least the width of the data bus. 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 10 Using Algorithms
Think of security—data security, communications security, information security, whatever—as a chain. The security of the entire system is only as strong as the weakest link. Everything has to be secure: cryptographic algorithms, protocols, key management, and more. If your algorithms are great but your random-number generator stinks, any smart cryptanalyst is going to attack your system through the random-number genera...
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