ENCYCLOPEDIA OF Espionage, Intelligence, and Security Volume ...

Cryo3 Detector❚ FURTHER READING:BOOKS:Gormley, Dennis. Dealing with the Threat of Cruise Missiles.New York: Oxford University Press for the InternationalInstitute for Strategic Studies, 2001.Huisken, Ronald. The Origin of the Strategic Cruise Missile.New York: Praeger Publishers, 1981.Werrell, Kenneth P. The Evolution of the Cruise Missile.Maxwell Air Force Base, AL: Air University Press, 1985.ELECTRONIC:Fact Sheet: AGM-86B/C Missiles. U.S. Air Force. (April 7, 2003).How Cruise Missiles Work. Howstuffworks.com. (April 7,2003).Navy Facts: Tomahawk Cruise Missile. U.S. Navy Officeof Information. (April 7, 2003).SEE ALSOBallistic MissilesBallistic Missile Defense Organization, United StatesGPSPatriot Missile SystemStrategic Defense Initiative and National Missile DefenseUndersea Espionage: Nuclear vs. Fast Attack SubsCryo3 Detector.SEE Lawrence Berkeley National Laboratory.❚ K. LEE LERNERCryptology andNumber TheoryCryptography is a division of applied mathematics concernedwith developing schemes and formula to enhancethe privacy of communications through the use of codes.More specifically, cryptography is the study of proceduresthat allow messages or information to be encoded (obscured)in such a way that it is extremely difficult to read orunderstand encoded information without having a specifickey (i.e., procedures to decode) that can be used toreverse the encoding procedure.Cryptography allows its users, whether governments,military, businesses or individuals, to maintain privacyand confidentiality in their communications. The goal ofevery cryptographic scheme is to be ”crack proof“ (i.e,only able to be decoded and understood by authorizedrecipients). Cryptography is also a means to ensure theintegrity and preservation of data from tampering. Moderncryptographic systems rely on functions associatedwith advanced mathematics, number theory that exploresthe properties of numbers and the relationships betweennumbers.Encryption systems can involve the simplistic replacementof letters with numbers, or they can involve theuse of highly secure ”one-time pads“ (also known asVernam ciphers). Because one-time pads are based uponcodes and keys that can only be used once, they offer theonly ”crack proof“ method of cryptography known. Thevast number of codes and keys required, however, makesone-time pads impractical for general use.Many wars and diplomatic negotiations have turnedin the ability of one combatant or country to read thesupposedly secret messages of its enemies. The use ofcryptography has broadened from its core diplomatic andmilitary users to become of routine use by companies andindividuals seeking privacy in their communications. Governments,companies and individuals required more securesystems to protect their databases and email.In addition to improvements made to cryptologicsystems based on information made public from classifiedgovernment research programs, international scientificresearch organizations devoted exclusively to theadvancement of cryptography (e.g., the International Associationfor Cryptologic Research (IACR)), began to applyapplications of mathematical number theory to enhanceprivacy, confidentiality, and the security of data. Applicationsof number theory were used to develop increasinglyinvolved algorithms (i.e., step-by-step procedures for solvinga mathematical problems). In addition, as commercialand personal use of the Internet grew, it became increasinglyimportant, not only to keep information secret, butalso to be able to verify the identity of message sender.Cryptographic use of certain types of algorithms called”keys“ allow information to be restricted to a specific andlimited audiences whose identities can be authenticated.Mathematical OperationsIn some cryptologic systems, encryption is accomplished,for example, by choosing certain prime numbers and thenproducts of those prime numbers as a basis for furthermathematical operations. In addition to developing suchmathematical keys, the data itself is divided into blocks ofspecific and limited length so that the information that canbe obtained even from the form of the message is limited.Decryption is usually accomplished by following an elaboratereconstruction process that itself involves uniquemathematical operations. In other cases, decryption isaccomplished by performing the inverse mathematicaloperations performed during encryption.In the late 1970s, government intelligence agenciesand Ronald Rivest, Adi Shamir, and Leonard Adlemanpublished an algorithm (the RSA algorithm) destined tobecome a major advancement in cryptology. The RSA286 Encyclopedia of Espionage, Intelligence, and Security