Scientists close to network that defies hackers

[R.A. Hettinga]

<http://news.ft.com/cms/s/a0dcf3f0-5874-11d9-9940-00000e2511c8.html>

The Financial Times



Scientists close to network that defies hackers
By Clive Cookson, Science Editor
Published: December 28 2004 02:00 | Last updated: December 28 2004 02:00
Scientists have taken what they say is a big step towards an intrinsically
secure computer network which banks and other institutions could use to
transmit data without risk of hacking.

Toshiba Research Europe is one of several laboratories around the world
racing to commercialise quantum cryptography, a technology that uses
quantum mechanics to generate unbreakable codes. The Cambridge-based
company says it has produced the first system robust enough to run
uninterruptedly for long periods without human intervention.

The Toshiba researchers have tested the system with MCI, the international
telecommunications company, and plan next year to carry out trials with
financial institutions in London.

Secure digital communication uses long prime numbers as keys to encode data
at one end and decode at the other. Inquantum cryptography, individual
photons - light particles - transmit the secret keys down optical fibres.
Each photon carries a digital bit of information, depending on its
polarisation. To outwit hackers, the keys are changed many times a second.

The extreme delicacy of these quantum bits is both the strength and
weakness of quantum cryptography. On the positive side, a hacker cannot
eavesdrop on the data transmission without changing it and alerting sender
and receiver to the breach of security. But the system is easily disturbed
by tiny fluctuations such as temperature changes in the transmission
apparatus or movements in the optical fibres.

Previous quantum cryptography transmissions have lasted only for minutes
and required continual adjustment by experts, says Andrew Shields, head of
Toshiba's quantum information group. His laboratory managed to extend the
running time to a week's "entirely automated and uninterrupted session".

The Cambridge researchers stabilised the system and reduced the error rate
by sending a bright "guardian pulse" of light down the fibres immediately
after each information-carrying photon.

Mr Shields said: "The technology is now sufficiently mature to be used in
real-world situations and we are currently discussing applications with
interested parties. In the first instance we expect quantum cryptography to
be used in companies' private networks - for example, to provide secure
traffic in a link between two sites within a metropolitan area."

Besides Japanese-owned Toshiba, large electronics companies competing to
commercialise quantum cryptography include NEC of Japan and Hewlett-Packard
of the US. There are also two start-ups, Magiq Technologies of the US and
ID Quantique of Switzerland, with first generation quantum cryptography
products on the market, although sales have not been large.
-- 
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R. A. Hettinga <mailto: rah at ibuc.com>
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'

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