Unformatted text preview: han today’s! Remember, too, that these numbers only relate to general-purpose computers; who knows what kind of specialized cryptosystem-breaking equipment will be developed in the next 50 years? Assuming that a cryptographic algorithm will be in use for 30 years, you can get some idea how secure it must be. An algorithm designed today probably will not see general use until 2000, and will still be used in 2025 to encrypt messages that must remain secret until 2075 or later. Table 7.10 Security Requirements for Different Information Type of Traffic Tactical military information Product announcements, mergers, interest rates Long-term business plans Trade secrets (e.g., recipe for Coca-Cola) H-bomb secrets Identities of spies Personal affairs Diplomatic embarrassments U.S. census data Lifetime minutes/hours days/weeks years decades >40 years >50 years >50 years >65 years 100 years Minimum Key Length 56–64 bits 64 bits 64 bits 112 bits 128 bits 128 bits 128 bits at least 128 bits at least 128 bits 7.6 Caveat Emptor
This entire chapter is a whole lot of nonsense. The very notion of predicting computing power 10 years in the future, let alone 50 years is absolutely ridiculous. These calculations are meant to be a guide, nothing more. If the past is any guide, the future will be vastly different from anything we can predict. Be conservative. If your keys are longer than you imagine necessary, then fewer technological surprises can harm you. 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)
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