Encyclopedia of Computer Science and Technology

220 handwriting recognitionand other commercial software so the disks could be copiedfreely and exchanged at computer fairs, club meetings,and on illicit bulletin boards (where they were known as“warez”). (See copy protection and intellectual propertyand computing.)The growing use of on-line services and networks in the1980s and 1990s brought new opportunities to exploit computerskills to vandalize systems or steal valuable informationsuch as credit card numbers. The popular media usedthe term hacker indiscriminately to refer to clever programmers,software pirates, and people who stole information orspread viruses across the Internet. The wide availability ofscripts for password cracking, Web site attacks, and viruscreation means that destructive crackers often have littlereal knowledge of computer systems and do not share theattitudes and philosophy of the true hackers who sought toexploit systems rather than destroy them.During the 1980s, a new genre of science fiction calledcyberpunk became popular. It portrayed a fractured, dystopianfuture where elite hackers could “jack into” computers,experiencing cyberspace directly in their mind, asin William Gibson’s Neuromancer and Count Zero. In suchtales the hacker became the high-tech analog of the cowboyor samurai, a virtual gunslinger who fought for high stakeson the newest frontier (see science fiction and computing).Meanwhile, lurid stories about such notorious realworldhackers (see Mitnick, Kevin) brought the dark sideof hacking into popular consciousness.By the turn of the new century, the popular face of hackingwas again changing. Some of the most effective techniquesfor intruding into systems and for stealing sensitiveinformation (see computer crime and identity theft)have always been psychological rather than technical. Whatstarted as one-on-one “social engineering” (such as posingas a computer technician to get a user’s password) hasbeen “industrialized” in the form of e-mails that frighten orentice recipients into supplying credit card or bank information(see spam and phishing and spoofing.) Criminalhackers have also linked up with more-traditional criminalorganizations, creating rings that can efficiently turn stoleninformation into cash.In response to public fears about hackers’ capabilities,federal and local law enforcement agencies have steppedup their efforts to find and prosecute people who crackor vandalize systems or Web sites. Antiterrorism expertsnow worry that well-financed, orchestrated hacker attackscould be used by rogue nations or terrorist groups to paralyzethe American economy and perhaps even disrupt vitalinfrastructure such as power distribution and air trafficcontrol (see counterterrorism and information warfare).In this atmosphere the older, more positive image ofthe hacker seems to be fading—although the free-wheelingcreativity of hacking at its best continues to be manifestedin cooperative software development (see open source).Further Reading2600 magazine. Available online. URL: http://www.2600.com.Accessed February 2, 2008.Erickson, Jon. Hacking: The Art of Exploitation. 2nd ed. San Francisco:No Starch Press, 2007.Gibson, William. Neuromancer. West Bloomfield, Mich.: PhantasiaPress, 1986.Hafner, Katie, John Markoff. Cyberpunk: Outlaws and Hackers onthe Computer Frontier. New York: Simon & Schuster, 1991.Harris, Shon, et al. Gray Hat Hacking: The Ethical Hacker’s Handbook.Berkeley, Calif.: McGraw-Hill/Osborne Media, 2004.Levy, Stephen. Hackers: Heroes of the Computer Revolution. NewYork: Doubleday, 1984.Littman, J. The Fugitive Game: On-line with Kevin Mitnick. Boston:Little, Brown, 1996.Mitnick, Kevin, and William L. Simon. The Art of Deception: Controllingthe Human Element of Security. Indianapolis: Wiley,2002.———. The Art of Intrusion: The Real Stories behind the Exploits ofHackers, Intruders & Deceivers. Indianapolis: Wiley, 2005.Raymond, Eric. The New Hacker’s Dictionary. 3rd ed. Cambridge,Mass.: MIT Press, 1996.handwriting recognitionWhile the keyboard is the traditional means for enteringtext into a computer system, both designers and users havelong acknowledged the potential benefits of a system wherepeople could enter text using ordinary script or printedhandwriting and have it converted to standard computercharacter codes (see characters and strings). With sucha system people would not need to master a typewriter-stylekeyboard. Further, users could write commands or takenotes on handheld or “palm” computers the size of a smallnote pad that are too small to have a keyboard (see portablecomputers). Indeed, such facilities are available to alimited extent today.A handwriting recognition system begins by buildinga representation of the user’s writing. With a pen or stylussystem, this representation is not simply a graphical imagebut includes the recorded “strokes” or discrete movementsthat make up the letters. The software must then create arepresentation of features of the handwriting that can beused to match it to the appropriate character templates.Handwriting recognition is actually an application of thelarger problem of identifying the significance of features ina pattern.One approach (often used on systems that work frompreviously written documents rather than stylus strokes)is to identify patterns of pixels that have a high statisticalcorrelation to the presence of a particular letter in the rectangular“frame” under consideration. Another approach isto try to identify groups of strokes or segments that can beassociated with particular letters. In evaluating such tentativerecognitions, programs can also incorporate a networkof “recognizers” that receive feedback on the basis of theiraccuracy (see neural network). Finally, where the identityof a letter remains ambiguous, lexical analysis can be usedto determine the most probable letter in a given context,using a dictionary or a table of letter group frequencies.Implementation and ApplicationsA number of handheld computers beginning with Apple’sNewton in the mid-1990s and the now popular Palm devicesand BlackBerry have some ability to recognize handwriting.However, current systems can be frustrating to use