applied cryptography - protocols, algorithms, and source code in c

There is no known way to break cast other than brute

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Unformatted text preview: ys are generated simply. The 256-bit key is divided into eight 32-bit blocks: k1, k2,..., k8. Each round uses a different subkey, as shown in Table 14.1. Decryption is the same as encryption with the order of the kis reversed. The GOST standard does not discuss how to generate the S-boxes, only that they are somehow supplied [655]. This has led to speculation that some Soviet organization would supply good S-boxes to those organizations it liked and bad S-boxes to those organizations it wished to eavesdrop on. This may very well be true, but further conversations with a GOST chip manufacturer within Russia offered another alternative. He generated the S-box permutations himself, using a random-number generator. Table 14.1 Use of GOST Subkeys in Different Rounds Round: Subkey: Round: Subkey: 1 1 17 1 2 2 18 2 3 3 19 3 4 4 20 4 5 5 21 5 6 6 22 6 7 7 23 7 8 8 24 8 9 1 25 8 10 2 26 7 11 3 27 6 12 4 28 5 13 5 29 4 14 6 30 3 15 7 31 2 16 8 32 1 More recently, a set of S-boxes used in an application for the Central Bank of the Russian Federation surfaced. These S-boxes are also used in the GOSTone-way hash function (see section 18.11) [657].They are listed in Table 14.2. 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) Go! Keyword 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: Go! Previous Table of Contents Next ----------- Cryptanalysis of GOST These are the major differences between DES and GOST. — DES has a complicated procedure for genera...
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This note was uploaded on 10/18/2010 for the course MATH CS 301 taught by Professor Aliulger during the Fall '10 term at Koç University.

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