Technicalities | Quantum leap

• By Kevin McCaney
• Oct 23, 2008

Quantum encryption isn't new, but it has been largely seen
as something on the horizon. Using the spin and polarization of
photons to represent ones and zeros represents a sure way to create
random, unbreakable cryptographic keys, but it has also seemed
beyond everyday use in terms of difficulty and expense.

However, this month, a European Union project, with the snappy
name of Development of a Global Network for Secure Communication
based on Quantum Cryptography, put quantum cryptography to work
with a demonstration of how it could be applied to networks. It has
been used only in pointto- point communications.

At a demonstration in Vienna, Austria, encrypted data was
transmitted via standard optical fiber to six locations, some as
far as away as 50 miles, Agence France-Presse reported. That seems
to have solved one of the difficulties of quantum cryptography,
which has been creating the keys quickly enough.

Quantum cryptography's security is twofold. The keys it
generates are random, based on the laws of quantum physics rather
than a computational scheme. And the nature of photons prevents
eavesdropping, because any attempt to read them alters their state.
The chance that agencies will be using it anytime soon is probably
small, but at least the horizon is a little closer.