[Home]History of Cryptology

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Revision 15 . . (edit) December 16, 2001 3:12 am by (logged).150.138.xxx
Revision 14 . . (edit) December 16, 2001 3:11 am by (logged).150.138.xxx
Revision 13 . . November 10, 2001 10:20 pm by Stephen Gilbert [moved information from [[cryptanalysis]]]
Revision 12 . . October 2, 2001 10:24 am by Larry Sanger
  

Difference (from prior major revision) (minor diff, author diff)

Changed: 1c1
Cryptology is an engineering discipline, informed by telecommunications engineering practice, the communications theory aspects of information theory (see Shannon and Weaver, Mathematical Theory of Communication, Univ of Ill Press, (about 1949), and Shannon's articles (in 1949?) in the Bell System Technical Journal on communications secrecy, and by the theory of computational complexity. The field is not a science in that questions of practicality and cost-effectiveness predominate in actual practice. Except in the sense that some proposed algorithm or protocol may be shown to be insecure under current conditions (cryptanalytic tools, computational capability, funding and staff available to an attacker, etc.), there is no opportunity to perform experimental tests of hypotheses about cryptopgraphic assertions. Cryptology is concerned with communications in secure, and often secret, form. It encompasses both cryptography and cryptanalysis. Some writers prefer to use cryptography as the overall term.
Cryptology is an engineering discipline, informed by telecommunications engineering practice, the communications theory aspects of information theory (see Shannon and Weaver, Mathematical Theory of Communication, Univ of Ill Press, (about 1949), and Shannon's articles (in 1949?) in the Bell System Technical Journal on communications secrecy, and by the theory of computational complexity. The field is not a science in that questions of practicality and cost-effectiveness predominate in actual practice, and experimental testing is wholly conditioned on tester resources. Except in the sense that some proposed algorithm or protocol may be shown to be insecure under current conditions (eg, the cryptanalytic tools, computational capability, funding and staff, ... available to an attacker), there is no opportunity to perform experimental tests of hypotheses about cryptopgraphic assertions. Cryptology is concerned with communications in secure, and often secret, form. Cryptology is often taken as a synonym for cryptography and occasionally for cryptanalysis as well, but specialists in the field have for years adopted the convention that cryptology is the more inclusive term, encompassing both cryptography and cryptanalysis. The word is sometimes ascribed to William Friedman of the US Army's Signal Intelligence Service in the '30s. However, some writers prefer to use cryptography as the overall term.

Changed: 3c3
The term cryptology is derived from the Greek kryptós, "hidden," and lógos, "word." Note that cryptology/cryptography encompasses much more than mere secrecy. Cryptographic security may result (when, and only when, well chosen algorithms and protocols are properly used); these intentions may include authentication of the participants to each other (with or without secrecy), integrity checks of messages sent (also with or without secrecy), and of course secrecy of the message sent. In most instances, secrecy obtains when legitimate users, the transmitter and the receiver, are able to transform information into a ciphertext? by use of an encryption algorithm (in all modern cases controlled by one of many possible [cryptographic key]?s) -- i.e., a piece of information which customizes the operation of the encryption algorithm. For a large class of such algorithms, the key is known to both users and must not be known by any other. Although the cipher is inscrutable and often unforgeable to anyone without this secret key, the authorized receiver can either decrypt the cipher to recover the hidden information or verify that it was sent in all likelihood by someone possessing the key.
The term cryptology is derived from the Greek kryptós, "hidden," and lógos, "word." Note that cryptology/cryptography encompasses much more than mere secrecy. Cryptographic security may result (when, and _only_ when, well chosen algorithms and protocols are properly used); these intentions may include authentication of the participants to each other (with or without secrecy), integrity checks of messages sent (also with or without secrecy), and of course secrecy of the message sent against the non-intended. In most instances, secrecy obtains when legitimate users, the 'sender' and the 'receiver', are able to transform information into a ciphertext? by use of an encryption algorithm (in all modern cases controlled at each invocation by one of many possible [cryptographic key]?s) -- i.e., a piece of information which customizes the operation of the encryption algorithm. For a large class of such algorithms, the key is known to both users and must not be known by any other. Although the cipher should be inscrutable and unforgeable to anyone without this secret key (and good ones correctly used will be), the authorized receiver can either decrypt the cipher to recover the hidden information or verify that it was sent in all likelihood by someone possessing the key.

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