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

Table 78 rivests optimistic key length

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Unformatted text preview: time.) Table 7.6 recommends different key lengths for security during different years. Table 7.6 Recommended Public-key Key Lengths (in bits) Year vs. Individual 1995 2000 2005 768 1024 1280 vs. Corporation 1280 1280 1536 vs. Government 1536 1536 2048 2010 2015 1280 1536 1536 2048 2048 2048 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 ----------- Remember to take the value of the key into account. Public keys are often used to secure things of great value for a long time: the bank’s master key for a digital cash system, the key the government uses to certify its passports, or a notary public’s digital signature key. It probably isn’t worth the effort to spend months of computing time to break an individual’s private key, but if you can print your own money with a broken key the idea becomes more attractive. A 1024-bit key is long enough to sign something that will be verified within the week, or month, or even a few years. But you don’t want to stand up in court 20 years from now with a digitally signed document and have the opposition demonstrate how to forge documents with the same signature. Making predictions beyond the near future is even more foolish. Who knows what kind of advances in computing, networking, and mathematics are going to happen by 2020? However, if you look at the broad picture, in every decade we can factor numbers twice as long as in the previous decade. This leads to Table 7.7. On the other hand, factoring technology may reach its Omega point long before 2045. Twenty...
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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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