Association for Computing Machinery
Timely Topics for IT Professionals

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ACM TechNews is published every week on Monday, Wednesday, and Friday.


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Volume 4, Issue 423: Friday, November 15, 2002

  • "Computing Moving from Innovation to Legislation"
    InternetNews.com (11/12/02); Wagner, Jim

    At the Computer Security Institute (CSI) convention in Chicago, director of Purdue University's Center for Education and Research in Information Assurance and Security (CERIAS) Gene Spafford told attendees on Tuesday that the computing industry is moving "from the technological innovation and business innovation [phase] to a consumer and regulatory phase." For example, right now the government regards online privacy in much the same way it regarded telephone privacy in the 1920s, in that it ruled that consumers should not expect any privacy until years later, when tapping phone lines was declared illegal without warrants. Although Spafford noted that the government is making progress with legislation designed to protect citizens and keep their private information secure, he added that Congress is paying more attention to industry lobbyists than actual consumers. Rather than offering consumers desirable services, software developers and content holders seem bent on protecting themselves from liability or shielding their copyrights. For example, Sen. Ernest Hollings' (D-S.C.) Consumer Broadband and Digital Television Promotion Act (CBDTPA) would fine digital equipment manufacturers that fail to include anti-piracy hardware in DVDs and PCs so that movies and music cannot be copied and played, but digital clocks, microwaves, and other products could also be equipped with the same safeguards. Meanwhile, the Uniform Computer Information Transaction Act (UCITA) has already been adopted by two U.S. states despite opposition from many groups such as the Association for Computing Machinery because lobbyists were able to successfully exploit their fear of being labeled anti e-commerce, Spafford explains. He noted that consumers will remain wary of new technologies purported to protect their online privacy until the Internet has been changed on a fundamental level.
    http://dc.internet.com/news/article.php/1499091

    Gene Spafford is co-chair of the USACM Committee. For more information on ACM's activities regarding security and UCITA, visit http://www.acm.org/usacm.

  • "Polymers Could Push Internet Speed"
    CNet (11/14/02); Junnarkar, Sandeep

    Bell Labs researchers have discovered through experimentation that certain polymers have the potential to greatly accelerate Internet speed, and such a breakthrough could lead to the real-time transfer of large video and audio files. "Basically, we are cramming a lot more electrical data onto an optical light wave in one second," explains Mark Lee of Bell Labs. Most widely used optical networks boast a data rate of 10 GHz, while Lee notes that current materials cannot support more than 40 GHz. The scientists' findings indicate that the rate could be boosted towards 145 GHz using specific polymers. "What we have done here specifically is to select the set of polymers with the right properties that can function at very fast speeds," Lee says. Another benefit of using polymers is their relatively cheap manufacturing cost, which could lead to less expensive optical equipment. However, Lee adds that technical challenges will keep such technology from hitting the market for at least five years. For one thing, the longer the distance a high-speed data transmission must travel, the faster the information contained in that signal degrades. The research team's findings will be released on Thursday in an online edition of Science Magazine.
    http://news.com.com/2100-1033-965874.html

  • "Study Makes Less of Hack Threat"
    Wired News (11/14/02); Shachtman, Noah

    A new report from England's mi2g finds a decline in the number of reported intrusions into government networks: American attacks fell from 386 to 162 between 2001 and the first 10 months of 2002, while attacks worldwide have fallen by around one-third. However, the overall level of hack attacks has climbed from 31,322 to 64,408 over the same period. Information Security magazine editor Lawrence Walsh attributes most intrusions to "script kiddies" who stand to gain more by assaulting small- and medium-sized businesses, whose networks are often poorly secured. Pearl Harbor Dot Com author Winn Schwartau adds that the mi2g report's exclusive reliance on publicly documented attacks could distort the actual number of hacks, and notes that the government is "increasingly reluctant" to publicly disclose network breaches. Security News Portal editor Marquis Grove dismisses the firm's statistics as "basically worthless," while hackers such as WBGLinks director Lilac Echo claim that such reports indicate that cyberterrorism is not taking place, nor is it likely to occur anytime soon. Some experts see recent legislation such as the USA Patriot Act and Cyber Security Research and Development Act as the product of scare-mongering by politicians. "Threats will always be exaggerated because that's how one strip mines civil liberties," declared Hacktivismo founder Oxblood Ruffin in an email.
    http://www.wired.com/news/politics/0,1283,56382,00.html

  • "HP Gets Patent, Recognition for Molecular Electronics Work"
    Nanotech Planet (11/13/02); Pastore, Michael

    Hewlett-Packard announced on Tuesday that it has received a patent for a chemical process that could be used to fabricate molecular electronic devices. Credited with inventing the process are HP Labs director of quantum science research R. Stanley Williams, HP senior scientist Philip J. Kuekes, and UCLA chemistry professor James R. Heath. "We aim to do nothing less than reinvent the computer and this patent is the foundation of the effort," Williams declared. Logic, memory, communications, and signal routing devices can be built with the process, which allows electrically switchable molecules to become ensnared between intersecting wires only a few atoms in width. Furthermore, the wires are not required to cross at precise points and angles, while the molecules' role can be determined after fabrication. Health believes that the methodology will extend the life of Moore's Law by five decades. Meanwhile, Kuekes, Williams, Heath, and fellow HP researcher Yong Chen's work with nano-imprint lithography and the advancement of molecular electronics collectively earned them the title of Research Leader in Manufacturing by Scientific American magazine. The honor was one of the Scientific American 50 recognized for scientific and technological achievements of the past year that promote a better future.
    Click Here to View Full Article

  • "It's How We Use Computers That Counts"
    Wall Street Journal (11/14/02) P. A2; Wessel, David

    The best strategy to boost productivity and business is not simply investing in information technology, but using it effectively. Despite cutbacks in computer budgets, U.S. productivity growth continues to maintain an annual gain of more than 2.5 percent since the late 1990s because companies are learning how to optimize their existing computer systems. The McKinsey Global Institute will release a report next week that analyzes why certain companies that purchased IT have done well while others have floundered. For example, the think tank observes that Kmart's costly IT investment to promote sales items did not pay off because the firm failed to develop a supply-chain infrastructure flexible enough to deal with wavering sales volumes. Target, however, found success by retooling its computers so that it could compete with Wal-Mart by rapidly exploiting the latest trends. An important conclusion is that IT usage differs for every retailer--Neiman Marcus and Saks, for example, use IT to maintain relationships with upscale customers and encourage them to spend more. Wal-Mart, in contrast, uses technology chiefly to scale back inventory and cut warehouse expenses. Many retail banks have yet to realize success, even though McKinsey estimates that over 10 percent of their revenue is diverted into IT investments; for instance, although sophisticated systems are in place that provide every teller counter with important data about customer finances, few banks are exploiting this function to sell new services.

  • "House Considers Jailing Hackers for Life"
    CNet (11/13/02); McCullagh, Declan

    The Cyber Security Enhancement Act (CSEA) was bundled into the proposed Department of Homeland Security bill the House of Representatives passed on Wednesday. Under the CSEA, hackers convicted of committing cybercrimes that "recklessly" endanger the lives of others would be sentenced to life imprisonment; Internet providers would be allowed to "knowingly divulge" user activities if they are categorized as critical to emergencies that could involve serious bodily harm; law enforcement would be able to conduct Internet and telephone eavesdropping without court orders if there is an immediate threat to national security or an "ongoing attack" on an Internet-linked computer; and both printed and online ads for devices that are mainly used for clandestine electronic surveillance would be banned. The House approved of the CSEA back in July, but the Senate did not. Supporters hope that its inclusion in the Homeland Security bill will ensure its passage, although both Senate and presidential approval is still required. Civil liberties advocates such as Electronic Privacy Information Center director Marc Rotenberg argue that the proposal will make ISPs more amenable to serving the interests of law enforcement than consumer privacy. Meanwhile, Democratic members of Congress claim that the Homeland Security bill was rushed to the floor before they could study it in detail. "I doubt more than 10 people in Congress know [what's] in the bill," lamented Rep. Henry Waxman (D-Calif.).
    http://news.com.com/2100-1001-965750.html

  • "A Wink Is Enough to Switch Off the PC"
    Alphagalileo (11/11/02)

    A PC that a user can control wirelessly using eye movements is just one of the projects under development in the Academy of Finland's Research Program on Proactive Information Technology (PROACT), which has entered its startup phase. The academy will fund the program with a three-year grant of over 5.3 million euros, while the French Ministry of Research will finance three PROACT projects with a 2 million-euro allocation. Sensor technology for measuring muscular changes already exists and is used by the medical industry, and Veikko Surakka of the University of Tampere will oversee the creation of prototype wireless sensors, wireless measurement technology, and data transfer. He expects a prototype wireless sensor patch that can be placed on the skin to debut in the spring of 2004. Other PROACT projects involve the development of a chair that can measure occupants' cardiac functions, and a home-based safety system that incorporates electromechanical EMFi film. The latter project would assist in the care of elderly people by detecting such things as incapacitating falls through the measure of sound and movement. Communication between different information systems is a high priority for proactive technology research, and Professor Julia Tuominen of the Helsinki University of Technology is leading the development of a middleware platform that can connect mobile and fixed computer systems; with such a breakthrough, mobile emergency units would be able to more easily keep in touch with headquarters. Proactive information technology research is also being carried out in the United States and Britain, while the fifth and sixth European Union framework programs also earmark funding for such projects.

  • "W3C Bows to Royalty-Free Pressure"
    ZDNet (11/14/02); Kane, Margaret

    A last-call working draft of the World Wide Web Consortium's (W3C) patents policy issued on Thursday removes a provision that would have allowed companies that own patents on technology used in W3C-authorized Web standards to charge royalties. Last year, the Internet standards body presented a proposal in which patent holders could collect royalties without restricting access of the technology to anyone. It was hoped that such a proposal would make companies less reluctant to cede the rights to their intellectual property, but members of the free software and open-source movements were especially critical of the suggestion. "The real tension there was that the vast majority of the working group supports the proposition that what's clearly desirable is [a] royalty-free [policy]," explains W3C patent policy working group Chairman Daniel Weitzner. The new draft indicates that only technologies deemed "essential for implementing the W3C specification" can be used free of royalties. Companies will still have the right to use their patents defensively. Should members refuse to license relevant patents on a royalty-free basis, the working group can still check the genuineness of patents, design around them, or pass the standard to another standards body.
    http://zdnet.com.com/2100-1105-965863.html

  • "Hunting Down the Pirates"
    Melbourne Age Online (11/05/02); Cochrane, Nathan

    Researchers from the Palo Alto Research Center, Hewlett-Packard, the University of Wollongong, Microsoft, and others will be among the presenters at the Association for Computing Machinery's workshop on Digital Rights Management (DRM 2002) to be held Nov. 18 in Washington, D.C. The day-long workshop precedes ACM's Conference on Computers and Security that begins Nov. 19. University of Wollongong computer security researchers Reihaneh Safavi-Naini and Yejing Wang will discuss their work on "traitor tracing," which uses a variety of algorithms to trace pirates who attempt to break the digital fingerprints embedded in the data streams of digital media content. The researchers say their method works when two pirates work together to avoid being traced by either creating a new encryption code or modifying the existing code so that it is untraceable. Safavi-Naini, who does not agree with the Digital Millennium Copyright Act (DMCA), says, "We showed that even if the pirate fingerprint loses some of its symbols and becomes shorter...we can still trace one person." Others presenting at the DRM 2002 workshop will include Princeton University professor Edward Felten, who was prevented from publishing his work that would expose security flaws in anti-piracy safeguards in violation of DMCA.
    http://www.theage.com.au/articles/2002/11/02/1036027090590.html

    For more information on the conference and the workshop, visit http://www.acm.org/sigs/sigsac/ccs/.

  • "Coax Goes Nano"
    Technology Research News (11/20/02); Smalley, Eric

    Harvard University researchers have adopted semiconductor assembly techniques used to build computer chips in order to construct nanoscale wires from multiple material layers. The wires are created by inducing a semiconductor vapor to condense around one side of a gold droplet, while additional material layers are formed around the wire by adjusting temperature or vapor concentration, explains Harvard chemistry professor Charles Lieber. Several prototype nanowires have been fabricated using a variety of core and shell materials: One wire consists of a 26-nm germanium core with an outer 15-nm layer of doped silicon; another features a 19-nm core of pure silicon and a shell of silicon combined with boron. A field-effect transistor was built by the researchers, who surrounded a doped silicon core with outer layers of germanium, silicon oxide, and doped germanium, and then hooked up a gate electrode to the outer germanium layer and source and drain electrodes to the inner germanium layer. The nanowires made using this technique could be incorporated into the fabrication of speedier chips, smaller lasers, and denser memory. Lieber says the team is working on using layered nanowires in the construction of nonvolatile random access memory, a high-performance field-effect transistor that could be combined with conventional electronic circuitry, and light-emitting devices. Zhong Lin Wang of the Georgia Institute of Technology says the Harvard method demonstrates that multiple material layers used in nanoscale electronic devices can be oriented along the width of nanowires, rather than along the length.
    Click Here to View Full Article

  • "Triple Gate, Double Play"
    IEEE Spectrum Online (11/02); Geppert, Linda

    Intel and others are working to produce a multi-gate, three-dimensional transistor that will offer significant boosts in computing power and speed; Intel's Robert Chau reported positive developments in its tri-gate array at the International Conference on Solid State Devices and Materials in September. Chau says that NMOS and PMOS tri-gate devices with 60-nm gate lengths, when fully activated, exhibit a higher drive current than any other non-planar CMOS device. Both the tri-gate transistor and its close relative, the double-gate FinFET transistor, are fabricated by etching the top layer of a silicon-on-insulator wafer to create a vertical fin that sits on the insulator layer. A layer of polysilicon is deposited and patterned over the top and sides of the silicon body, thus forming the tri-gate configuration, while the source and drain areas are epitaxially thickened. The tri-gate device can lower overall power consumption by reducing the conduction between source and drain when the device is deactivated through the process known as full depletion. Intel's device could appear in microprocessor products by 2010, said Gerald Marcyk, the company's director of components research. Such a breakthrough could pave the way for computers that can understand human speech and foreign languages.
    http://www.spectrum.ieee.org/WEBONLY/wonews/nov02/trigate.html

  • "Tech Taps Into Portable Power Sources"
    ZDNet (11/13/02); Junnarkar, Sandeep

    Work is proceeding apace in universities and scientific laboratories on alternative energy sources for portable electronics in response to a mandate from the consumer electronics industry to shrink devices down and replace nickel cadmium batteries with longer-lasting models. In October, a Cornell University team revealed a device that converts radiation emitted by a decaying isotope into mechanical motion that drives machine parts to produce electricity. Team leader Amit Lal estimates that the atomic battery could last for decades, and predicts that consumer cell phones equipped with such batteries could be available within about three to four years. Meanwhile, Canada's Alberta Research Council (ARC) announced this week that they have developed a working prototype of a hydrogen gas fuel cell that can also run on other gases. "We're still in the early stages of research and development, but our focus is on developing an energy source that is easy to start up and will provide a high degree of power in a relatively small space, such as a cell phone, laptop or PDA," notes ARC senior research scientist Partho Sarkar. Still other research efforts are focusing on solar cells and fuel cells driven by methane, while the U.S. Department of Transportation recently made a significant stride toward the commercial adoption of methanol-powered fuel cells by allowing them to be taken on aircraft. As fuel cells and better batteries emerge, cell phones and laptops are likely to be radically modified into smaller, more powerful versions.
    http://zdnet.com.com/2100-1103-965640.html

  • "Teething Pains"
    Boston Globe (11/11/02) P. C1; Bray, Hiawatha

    After years of being touted as the networking system of the future, Bluetooth-enabled devices are finally on the market in force, but the wireless technology still suffers from compatibility problems despite several years of industry-wide development. Although Bluetooth chips should allow laptops to connect to the Web via Internet-enabled mobile phones, for example, it still largely depends on whether a device recognizes the complete functions of another device. Each Bluetooth-enabled device needs to be configured to work with other types of devices, such as printers, PDAs, phones, and computers. However, many Bluetooth products made specifically for mobile phones work well, most likely because of the strong interest shown by mobile phone manufacturers and the fact that it was created by mobile phone company Ericsson. Eric Janson of Cambridge Silicon Radio, which makes Bluetooth chips, says most of the roughly 25 million Bluetooth chipsets sold to date have been bought by cell phone manufacturers. Meanwhile, PC companies have been slow to adopt the standard, as evidenced by Microsoft's decision not to include Bluetooth compatibility in its first version of Windows XP, though it is available now as a free upgrade. Meanwhile, a rival wireless networking technology named WirelessUSB, from Cypress Semiconductor, aims to replace the function of USB (Universal Serial Bus) cables now the norm for PCs and their peripheral devices. That system would not need any special software configuration, according to Cypress vice president Cathal Phelan, because the PC would recognize the signals as normal USB transmissions.
    Click Here to View Full Article

  • "New IT Job Hot Spots"
    eWeek (11/11/02) Vol. 19, No. 45, P. 43; Vaas, Lisa

    The economic recession may have depressed business and job hirings in major tech hubs such as Silicon Valley and Seattle, but growth in other industries has caused new IT centers to sprout in places such as New York's Capital Region, Southern California, and Northern Virginia. Tech companies are flourishing in the N.Y. Capital Region because state financial support appeals to them, and a wealth of tech education institutions such as the State University of New York (SUNY) at Albany can provide future IT manpower. Tech skills in demand in the region include bioinformatics, networking, and mainstream IT work, while IBM is building a nanotechnology center at SUNY Albany that needs qualified personnel. The Bureau of Labor Statistics (BLS) estimates that more jobs have popped up in Southern California's Riverside-San Bernadino region than in any other U.S. area this year, and the key drivers of this growth are the distribution and logistics industry and biomedical companies. Logistics is a particularly lucrative field for job seekers with specialized IT skills. Biomedical firms such as Guardent do not require prospective workers to have industry experience, although there is emphasis on previous work in a regulated environment. There are plenty of IT jobs available from defense contractors located in the Washington Beltway and Northern Virginia area, but filling them is difficult because many require candidates to have security clearance as well as multiple IT skills. Meanwhile, jobs in the biomedical sector are likely to become available as firms and organizations such as Eli Lilly and the Howard Hughes Medical Center establish branches or open campuses in the region.
    http://www.eweek.com/article2/0,3959,687141,00.asp

  • "Government Gains Ground"
    InformationWeek (11/11/02) No. 914, P. 77; McGee, Marianne Kolbasuk

    Government IT workers score 3 percent to 5 percent better in server administration technologies such as Unix, Linux, and Windows systems than their private-sector counterparts, according to a new study from Brainbench, an online certification testing firm. Government IT systems often have more complex authorization levels based on security clearances, which may make them more familiar with server complexities. However, private-sector workers scored much better in networking, database, Internet, and programming skills, largely because the government often outsources those tasks, says Brainbench CEO Michael Russiello. Former acting CIO for the Treasury Department, Mayi Canales, says the government is especially looking for managers who can lead large interagency deployments of off-the-shelf applications. The government sector is beginning to look more attractive to tech workers as corporate IT spending continues to be cut and the government works to make its salaries more competitive. In addition, agencies are trying to respond to recommendations from the federal CIO Council and National Academy of Public Administration by streamlining its hiring process. Still, Ray Bjorklund of Federal Sources says the government sector is not hiring fast enough to make up for the large influx of tech workers laid off by companies. But the government is trying to shorten that time in response to recommendations from the National Academy of Public Administration and the CIO Council.
    http://informationweek.com/story/IWK20021107S0008

  • "Displaying the Future"
    PC Magazine (11/19/02) Vol. 21, No. 20, P. 70; Poor, Alfred

    Within five years, the computer screen market may still be dominated by liquid-crystal display (LCD) and cathode-ray tube (CRT) technology, or they could be ousted by one or more alternative displays under development, the hottest being carbon-based organic light-emitting diode (OLED) displays. OLED displays, which could show up in PDAs or notebooks as early as next year, do not require backlighting and can be viewed from any angle, and are thinner than LCD panels and smaller than CRTs. Mass-producing them cheaply via ink-jet printing also shows promise, but their sensitivity to air and moisture, their need for an active matrix to support resolution, and decreasing light emission as they age represent a daunting technical challenge. Another area of development is flexible displays that replace glass substrates with plastic, affording such advantages as cost-saving roll-to-roll production. Technical hurdles include building an active matrix by incorporating transistors for each pixel position; companies such as Alien Technology and FlexICs are making strides in this direction with their respective development of fluidic self assembly and a low-temperature method of creating polysilicon on cheap and flexible polymer substrates. A third technology being looked into is bistable displays, also known as electronic paper; the pixels of such displays retain their on and off states even after power is cut off, thus boosting battery life. Drawbacks to bistable displays include the lack of a mass production technology, slow response times, and unrefined materials. Other technologies that could give LCDs and CRTs a run for their money include field-emission displays (FEDs), microdisplays, front projection, and plasma display panels.
    http://www.pcmag.com/article2/0,4149,643201,00.asp

  • "Sending a Message"
    CIO (11/01/02) Vol. 16, No. 3, P. 102; Edwards, John

    The use of instant messaging (IM) software among companies demonstrates that the tool's applications, which until recently were mainly for social use, are suitable and desirable within the enterprise. IM supports direct message delivery to desktops and can manage simultaneous message transmissions to vast numbers of users, but Osterman Research President Michael Osterman reports that corporate adoption of IM is slow compared to worker demand. There are concerns that IM software will give hackers a new target of opportunity, because many consumer-grade applications lack security. Adding to the problem are compatibility issues--messages from rival systems cannot be displayed on most IM applications--and worries that productivity will suffer because of the technology's potential for distraction and time consumption; headaches such as these are the reason why many companies bar IM traffic from their network. However, there are arguments that IM has the potential to positively impact productivity, and some companies are reporting significant cost savings: For instance, Avnet Computer Marketing has reduced the need to make expensive international phone calls by deploying IM. The growing corporate adoption of IM will probably lead to the bundling of messaging capabilities in many popular business applications, including accounting and word processing. Enterprise IM will eventually support anytime, anywhere messaging and encompass a diverse assortment of platforms. ComScore Networks calculates that active corporate IM users grew 10 percent to 17.4 million users in the first half of 2002.
    http://www.cio.com/archive/110102/et_article.html

  • "Venturing to Vote Online"
    Technology Review (11/02) Vol. 105, No. 9, P. 26; Diop, Julie Claire

    European governments are moving ahead with pilot programs of Internet voting systems: Switzerland embarked on a $20 million e-voting project in 2001; last May, 16 e-voting or electronic ballot counting programs were carried out in the United Kingdom; and an Italian e-voting system is currently being tested. Among the problems these various initiatives are supposed to address are the prevention of voter ID theft, guaranteeing that e-voting systems are safe from hackers, and protection of voter privacy. Geneva is pushing a system in which in-transit data is shielded from hackers by encrypting votes and voters' identities, and it is hoped that the votes will remain impenetrable after they reach the database by separating them from voters' IDs and scrambling their order. The British government is investigating the possibility of giving each voter in a test district a unique code for each candidate. Meanwhile, the Italian government plans for voters to identify themselves by passing smart cards through electronic readers and entering passwords. All of these privacy protections could make it difficult to audit election results should inconsistencies crop up, critics contend. Much more effective, they argue, are conventional voting systems that guarantee voter anonymity and offer officials a foolproof way to trace votes. The United States is more reluctant than Europe to make e-voting investments, partly because of security concerns and a lack of funding. However, members of the U.S. military stationed overseas were allowed to vote online during the 2000 presidential election. MIT political scientist Stephen Ansolabehere expects a "decent" e-voting system to be in place within a decade.
    http://www.technologyreview.com/articles/innovation11102.asp

  • "Future Tech: Good-bye, Mr. Edison"
    Discover (11/02) Vol. 23, No. 11; Savage, Neil

    The incandescent light bulb could be rendered obsolete thanks to breakthroughs in light-emitting diodes (LEDs), which offer longer life and more efficiency, durability, and portability. The University of Calgary's Dave Irvine-Halliday believes LEDs will eventually replace conventional light bulbs and become the world's dominant source of artificial lighting. LED technology has come a long way in the last four decades, since researchers placed semiconductor crystals in clear epoxy and bombarded them with electrical current to generate photons; early products were LEDs that only glowed red and green, but later advances in red LED intensity and blue LEDs has made it possible to reproduce most of the color spectrum by combining red, blue, and green LEDs. There has been a rapid proliferation of LED-equipped traffic lights because the LEDs can last between five and 10 years and consume 80 percent to 90 percent less electricity than conventional models. Leading light bulb manufacturers are partnering with semiconductor makers to make the dream of a cheap, efficient white-light LED a reality. The Optoelectronics Industry Development Association says that white LEDs could halve the United States' electricity consumption by 2020, reduce carbon emissions by 20 million tons annually, and save $100 billion. Blending red, blue, and green LEDs is one way to build a white LED, and the circuitry required to maintain the proper mix of hues is a good control mechanism, according to Jerry Simmons of Sandia National Laboratories. Meanwhile, Boston University's Fred Schubert has devised a scheme in which a blue LED is coupled to a yellow-emitting semiconductor to produce white light, which could lend itself to hallway and outdoor illumination.
    http://www.discover.com/nov_02/feattech.html