antum communications and cryptography. Most current photon detectors operate best with visible light, cannot reli- ably detect single photons, and suffer from high dark counts due to random electronic noise. The new device operates with the wavelength of near-infrared light used for fiber optic communications and produces negligible dark counts. Instead of using light-sensitive materials, the NIST device uses a tungsten film coupled to a fiber-optic communication line. The film is chilled to minus 120,000,000, at its transition temperature between normal conductivity and QUANTUM CRYTOGRAPHY superconductivity. When the fiber-optic line delivers a photon to the tungsten film, the temperature rises and the apparatus detects it as an increase in elec- trical resistance. The device detects about 20,000 photons per second and works with an efficiency of about 20 percent. With planned improvements, the research team hopes to increase efficiencies to greater than 80 percent. 7.8.3 Distance Record Although quantum encryption sounds good in theory, the technique must be able to cope with real-word conditions. Specifically, the approach must be compatible with everyday communications networks. Researchers at Toshiba Research Europe have broken the distance record for the only potentially hacker-proof form of communications: quantum cryptography. The Toshiba research team, based in Cambridge, United Kingdom, was the first in the world to demonstrate successful quantum cryptography over 100 kilometers of optical fiber, showing the possibility of broad commercial poten- tial. Likely quantum cryptography adopters include any organization that uses Internet and communications technologies to send, receive, and store sensi- tive information, including banks, retailers, and central and local government organizations. Cryptography, the science of information security, is essential to protecting electronic business communication and e-commerce transactions. It allows message confidentiality, user identification, and secure transacti