Encyclopedia of Computer Science and Technology

Diffie, Bailey Whitfield 145DHTML See html, dhtml, and xhtml.Diffie, Bailey Whitfield(1944– )AmericanMathematician, Computer ScientistThe device driver is the link between the operating system andthe hardware that controls a specific device. Program requests arepassed by the operating system to the device driver, which issues thedetailed instructions needed by the device controller.implement a feature called plug and play. This allows for anewly installed device to be automatically detected by thesystem and the appropriate driver loaded into the operatingsystem (see plug and play). Other device managementcomponents enable the OS to keep track of the driver versionassociated with each device. Some of the newest operatingsystems include auto-update features that can search onthe Web for the latest driver versions and download them.The need to provide drivers for popular devices createssomething of a barrier to the development of new operatingsystems. In a catch-22, device manufacturers are unlikely tosupport a new OS that lacks significant market share, whilethe lack of device support in turn will discourage usersfrom adopting the new OS. (Users of the Linux operatingsystem faced this problem. However, that system’s opensource and cooperative development system made it easierfor enthusiasts to write and distribute drivers without waitingfor manufacturers to do so.)Further ReadingMr. Driver: Device Drivers. Available online. URL: http://www.mrdriver.com. Accessed July 8, 2007.Oney, Walter. Programming the Microsoft Windows Driver Manual.2nd ed. Redmond, Wash.: Microsoft Press, 2005.Rubini, Alessandro, and Jonathan Corbet. Linux Device Drivers.3rd ed. Sebastapol, Calif.: O’Reilly, 2005.Windows Driver Kit (WDK) Overview. Available online. URL:http://www.microsoft.com/whdc/devtools/wdk/default.mspx.Accessed July 8, 2007.Bailey Whitfield Diffie created the system of public keycryptography that many computer users depend on todayto protect their sensitive information (see encryption).Diffie was born on June 5, 1944, in the borough ofQueens, New York City. As a youngster he read about secretcodes and became fascinated. Although he was an indifferenthigh school student who barely qualified for graduation,Diffie scored so high on standardized tests that he wonadmission to the University of California, Berkeley, in 1962,where he studied mathematics for two years. However, in1964 he transferred to the Massachusetts Institute of Technology(MIT) and obtained his B.S. in mathematics in 1965.After graduation Diffie took a job at Mitre Corporation,a defense contractor, where he plunged into computer programming,helping create Mathlab, a program that allowedmathematicians to not merely calculate with a computer,but also to manipulate mathematical symbols to solve equations.(The program would eventually evolve into Macsyma,a software package used widely in the mathematical community—seemathematics software.)By the early 1970s Diffie had moved to the West Coast,working at the Stanford Artificial Intelligence Laboratory(SAIL), where he met Lawrence Roberts, head of informationprocessing research for ARPA, the Defense Department’sresearch agency. Roberts’s main project was thecreation of the ARPAnet, the computer network that wouldlater evolve into the Internet.Roberts was interested in providing security for the newnetwork, and (along with AI researcher John McCarthy)he helped revive Diffie’s dormant interest in cryptography.By 1974 Diffie had learned that IBM was developinga more secure cipher system, the DES (Data EncryptionStandard), under government supervision. However, Diffiesoon became frustrated with the way the National SecurityAgency (NSA) doled out or withheld information on cryptography,making independent research in the field verydifficult. Seeking to learn the state of the art, Diffie traveledwidely, seeking out people who might have fresh thoughtson the subject.Diffie found one such person in Martin Hellman, a Stanfordprofessor who had also been struggling on his own todevelop a better system of encryption. They decided to pooltheir ideas and efforts, and Diffie and Hellman came upwith a new approach, which would become known as publickey cryptography. It combined two important ideas thathad already been discovered to an extent by other researchers.The first idea was the “trap-door function”—a mathematicaloperation that can be easily performed “forward”but that was very hard to work “backward.” Diffie realized,however, that a trap-door function could be devised that