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

Blowfish is not suitable for applications such as

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Unformatted text preview: ting the subkeys from the keys. GOST has a very simple procedure. — DES has a 56-bit key; GOST has a 256-bit key. If you add in the secret S-box permutations, GOST has a total of about 610 bits of secret information. Table 14.2 GOST S-Boxes S-box 1: 4 10 9 S-box 2: 14 11 4 S-box 3: 581 S-box 4: 7 13 10 S-box 5: 6 12 7 S-box 6: 4 11 10 S-box 7: 13 11 4 S-box 8: 2 13 8 0 14 6 11 1 3 8 12 7 1 0 6 15 5 7 0 5 9 5 3 9 11 3 12 6 13 15 10 2 4 9 2 13 10 3 1 1 0 1 0 5 7 3 8 14 15 12 7 6 15 14 4 4 12 11 2 14 0 5 9 6 3 15 13 8 2 1 10 9 6 8 11 2 13 3 9 0 12 15 14 8 2 12 15 5 10 14 7 1 15 13 0 5 7 10 4 9 2 3 14 6 11 8 12 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 ----------- — The S-boxes in DES have 6-bit inputs and 4-bit outputs; the S-boxes in GOST have 4-bit inputs and outputs. Both algorithms have eight S-boxes, but an S-box in GOST is one-fourth the size of an S-box in DES. — DES has an irregular permutation, called a P-box; GOST uses an 11-bit left circular shift. — DES has 16 rounds; GOST has 32 rounds. If there is no better way to break GOST other than brute force, it is a very secure algorithm. GOST has a 256-bit key—longer if you count the secret S-boxes. Against differential and linear cryptanalysis, GOST is probably stronger than DES. Although the random S-boxes in GOST are probably weak...
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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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