The distance man: Toshiba's head of Quantum Information is seeking to extend the range at which computers can communicate in 'unhackable' code

Engineer, The, November, 2003 by Julia Pierce

THE FIRST device that relies on quantum mechanics to create unhackable computer codes was unveiled earlier this month. The Navajo Secure Gateway launched on 3 November in the US, and similar products yet to be launched, prove it is possible to use the most intriguing of physical laws for encrypting information. Now the race to be first to market is over, a new question arises over how practical this first generation of devices will actually be.

The big snag with quantum cryptography is the relatively limited distance over which such encoded information can be successfully transmitted. This problem is the focus of work being carried out by Toshiba's Quantum Information Group, led by Dr Andrew Shields at the company's Cambridge laboratories.

Shields is working...