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

Encryption of Dataprogram, which mobilizes community resources; the Radiationprogram; and the Office of Underground StorageTanks, which protects against the release of petroleumfrom underground tanks.An example of the EPA emergency response teams atwork alongside their counterparts from other federal agenciesoccurred in the aftermath of the September 11, 2001,terrorist attacks, when the EPA sent more than 200 personnelto the World Trade Center and Pentagon sites. Amongtheir ranks were specialists whose roles are not commonlyassociated with EPA in the public imagination,including criminal investigators, forensic scientists, andtechnical experts.❚ FURTHER READING:BOOKS:An Overview of the Emergency Response Program. Washington,D.C.: U.S. Environmental Protection Agency,1992.PERIODICALS:Hogue, Cheryl. “Regulators at Scenes of Attacks.” Chemical& Engineering News 79, no. 39 (September 24,2001): 11.Wallgren, Christine. “EPA Team Does Its Work Behind theScenes.” Boston Globe. (August 1, 2002): 1.ELECTRONIC:Emergency Response Program. U.S. Environmental ProtectionAgency. (February 23, 2003).U.S. National Response Team. (January 22, 2003).SEE ALSOChemical Safety: Emergency ResponsesCoast Guard National Response CenterEPA (Environmental Protection Agency)National Response Team, United States❚ LARRY GILMANEncryption of DataData are any useful information and encryption is anyform of coding, ciphering, or secret writing. Encryption ofdata, therefore, includes any and all attempts to conceal,scramble, encode, or encipher any information. In themodern world, however, the term data usually impliesdigital data, that is, information in the form of binary digits(“bits,” most often symbolized as 1s and 0s). Digital dataare stored, transferred, and processed in increasinglylarge quantities at virtually every level of government andin the private sector, especially in industrialized countries.Money is transferred between accounts or disbursed fromEncyclopedia of Espionage, Intelligence, and Securityautomatic teller machines on the basis of exchanges ofdigital data; medical records, criminal records, tax records,personal documents and telephone conversations,business negotiations, diplomatic communications, andmilitary communications are all, almost without exception,cast into digital form before being transmitted orstored. All transmission media are vulnerable, however,to interception, and stored records may be accessed byunauthorized persons. The need for encryption of digitaldata is almost universal; anyone who transfers or storesimportant digital data has an interest in its security.Governments have always had the strongest interestin data encryption, both as users of ciphering and codingsystems (cryptosystems) and as attackers of thecryptosystems of other governments. The United Statesgovernment, for example, uses encryption for transmissionnot only of classified (officially secret) data, but alsoof many unclassified data. Encryption is thus, distinct fromclassification. Classification is the official assignment of aparticular degree of secrecy to data, whereas encryptionrefers to the translation of data, classified or not, into aform that is difficult for unauthorized parties to read.Methods of encryption. Because digital data are numerical,their efficient encryption demands the use of cipheringrather than coding. A cipher is a system of rules fortransforming any message text (the plaintext) into anapparently random text (the ciphertext) and back again.Digital computers are ideal for implementing ciphers;virtually all ciphering today is performed on digital data bydigital computers.The U.S. military, the State Department, and the intelligenceagencies (including the Central Intelligence Agency,Federal Bureau of Investigation, National Security Agency[NSA], and others), utilize a variety of secret cipheringmethods or “cryptosystems,” whose nature is classifiedand about which little information is publicly available.The NSA, which is dedicated to eavesdropping—that is, tothe collection of “signals intelligence” (sigint) both in theU.S. and globally, devotes millions of dollars annually tothe breaking of ciphers and codes, and is the world’sleading employer of mathematicians and purchaser ofcomputer hardware. In the military, different cryptosystemsare employed to achieve different levels of security, rangingfrom person-to-person communications on the battlefieldto the exchange of messages with nuclear submarinesat sea and other critical, high-end applications wherebudgets run high.Government departments handling nonclassified information,industrial and academic organizations, andprivate individuals produce and transmit even greaterquantities of data than do the military, intelligence agencies,and other handlers of classified data. Because of boththe private sector and governmental need for reliable,standardized ciphering of nonclassified data, the NationalBureau of Standards (an arm of the federal government)first solicited proposals for “cryptographic algorithms for395