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Cytat
Do celu tam się wysiada. Lec Stanisław Jerzy (pierw. de Tusch-Letz, 1909-1966)
A bogowie grają w kości i nie pytają wcale czy chcesz przyłączyć się do gry (. . . ) Bogowie kpią sobie z twojego poukładanego życia (. . . ) nie przejmują się zbytnio ani naszymi planami na przyszłość ani oczekiwaniami. Gdzieś we wszechświecie rzucają kości i przypadkiem wypada twoja kolej. I odtąd zwyciężyć lub przegrać - to tylko kwestia szczęścia. Borys Pasternak
Idąc po kurzych jajach nie podskakuj. Przysłowie szkockie
I Herkules nie poradzi przeciwko wielu.
Dialog półinteligentów równa się monologowi ćwierćinteligenta. Stanisław Jerzy Lec (pierw. de Tusch - Letz, 1909-1966)
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.At itsannual conference in January 1997, RSA Data Security offered prizes for searching keyspaces ofvarious sizes.The 40-bit prize was claimed before the conference ended and the 48-bit prize wasclaimed a week later.The 56-bit DES challenge lasted for only 5 months.The US Data Encryption Standard uses a 56-bit key and thus falls within the range we have described as clearly possible.The standard is used extensively throughout the commercial world particularly bybanks, which commonly engage in billion-dollar electronic funds transfers.In such applications, theinadequacy of any algorithm with a 56-bit key is becoming apparent.Because the National Institute ofStandards and Technology (NIST) has yet to issue a replacement standard, 19 triple-DES a blockcipher employing DES three times in a row with three different keys20 has arisen as a de factostandard and is being considered for formal adoption by the Banking Security Standards Committee(ANSI X9F) of the American National Standards Institute.Lifetimes of CryptosystemsIn designing a cryptographic system, there are two important lifetime issues to consider: how longthe system will be in use and how long the messages it encrypts will remain secret.Cryptographic systems and cryptographic equipment often have very long lifetimes.The Sigabasystem, introduced before World War II, was in use until the early 1960s.The KL-7, a later rotormachine, served from the 1950s to the 1980s.DES has been a US standard for more than 20 years.21Other systems that are neither formal standards nor under the tight control of organizations such asthe American military probably have longer lifetimes still.22Secrets can also have very long lifetimes.The Venona messages were studied for nearly 40 years inhopes that they would reveal the identities of spies who had been young men in the 1930s and whomight have been the senior intelligence officers of the 1970s.The principles of the Sigaba systemwere discovered in the mid 1930s and were not made public until 1996.Much of the "H-bombsecret" has been kept since its discovery in 1950, and the trade secrets of many industrial processesare much older.In the United States, census data, income tax returns, medical records, and otherpersonal information are supposed to be kept secret for a lifetime.If we set out to develop a piece of cryptographic equipment today, we might reasonably plan to haveit in widespread use by the year 2000.We might also reasonably plan for the system to be in use for20 or 25 years.No individual piece of equipment is likely to last that long; however, if the product issuccessful, the standards it implements will.If the equipment is intended for the protection of a broadrange of business communications, some of the messages it encrypts may be intended to remainsecret for decades.A cryptosystem designed today might thus encrypt its last message in 2025, andthat message might be expected to remain secret 25 years later.It must therefore withstand attack bya cryptanalyst whose mathematical and computing resources we have no way of predicting in theyear 2050.The prospect is daunting.Key Management Key management the production, shipment, inventorying, auditing, and destruction of cryptographickeys is an indispensable component of secure communication systems.Cipher machines make aspectacular reduction in the amount of keying material that users must ship around.This diminishesthe problem of key distribution; however, it does not eliminate it, since the difficulty of distributingkeys is typically more a function of how many people are involved than of whether each one has toget a large codebook or a short message.The production of keys is the most sensitive operation in cryptography.Cryptographic keys must bekept secret and must be impossible for an opponent to predict.If they do not achieve these objectives,the results will be disastrous, regardless of how cleverly designed the cryptographic systems in whichthey are used.The failure of Soviet key production that led to the breaking of the Venona interceptsis one example of this.A far more recent example is the penetration of the Netscape Secure SocketLayer (SSL) protocol, which is used to secure Internet transactions by encrypting such sensitiveinformation as credit card numbers
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