<http://www.asahi.com/english/nation/TKY200405130208.html>
The Asahi Shimbun Researchers unlock the key to `unbreakable' coded messages TSUKUBA, Ibaraki Prefecture-The Holy Grail of data transmission-practical communication of encrypted messages impervious to eavesdroppers-may finally be within reach. On Wednesday, researchers at the National Institute of Advanced Industrial Science and Technology here announced they had developed the world's fastest quantum cryptography technology, which one day could be used to transmit sensitive diplomatic, military and financial information requiring the utmost confidentiality. Japanese, American and European companies have all been hard at work trying to produce a quantum cryptography system that could quickly send encrypted data over optical fiber cables. Encrypted information is already being transmitted over the Internet, but the new technology would allow for the encryption ``key'' necessary to code and decode the message to be supplied ahead of the message itself over public channels. Akio Yoshizawa and his research team have developed a technology that puts together the encryption key about 100 times faster than current methods. Until now, using quantum cryptography to send several pages of text containing about 60 kilobytes of data over a distance of about 100 kilometers was a time-consuming endeavor. Although the encrypted document itself can be transmitted over the Internet in a comparatively short period, it usually took about 13 hours to produce the encryption key and transmit that safely to the receiver. Using the new technology, the key can be sent in only eight minutes. In making their key, Yoshizawa's team used a binary system for representing the polarization of photons. Polarization refers to the angle at which a photon vibrates. Any attempt by a hacker to eavesdrop on the encryption key disturbs the photon's polarization and lets the receiver know that someone has attempted to steal the key. Rather than allow the eavesdropper to steal the key, all the sender and receiver have to do is agree on a new key for encrypting the information to be sent. The key can be changed any number of times until both parties are sure that it has not been tampered with before transmitting the actual information in encrypted form. The technology, though, has a number of weaknesses. For example, eavesdroppers aside, the photons have to be sent in such a way that they will not be disturbed. Until now, this has meant that photons could only be sent via optical fiber cable over short distances. The problem is, this method is susceptible to unwanted noise. However, Yoshizawa and his group have developed an optical detector that can reduce the noise level over a 10.5-kilometer optical fiber cable. This also reduces the transmission time. The new technology developed allows for the transmission of the key at 45 kilobits of data a second, or about 100 times current speeds.(IHT/Asahi: May 13,2004) (05/13) -- ----------------- R. A. Hettinga <mailto: [EMAIL PROTECTED]> The Internet Bearer Underwriting Corporation <http://www.ibuc.com/> 44 Farquhar Street, Boston, MA 02131 USA "... however it may deserve respect for its usefulness and antiquity, [predicting the end of the world] has not been found agreeable to experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire' --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]
