According
to reliable sources from NEC, Commercial quantum cryptography, a
revolutionary system that can produce quantum keys at a speed of
100Kbit/s and then broadcast it up to 40 kilometres along the
commercial fibre optic lines will be available in the markets by the
second half of 2005. Speaking
in line with Kazuo Nakamura, senior manager of NEC's quantum
information technology group at the company's Fundamental and
Environmental Research Laboratories, it can be considered as a world
record as it is a rare blend of speed and distance. As put by Akio
Tajima, the assistant manager at the laboratory, this innovative
concept has gone through several improvisations after it was
successfully tested in April at the company’s laboratories in Tokyo.
The
system permits the users to swap the keys with a prior idea that they
have not been disordered up during the transmission. The whole system
works on the concept that the system works by implanting the encryption
key on photons, which can be either in the receiver end or with an
eavesdropper, as the photons cannot be cracked. Akio
Tajima said that until last April the round-trip’ quantum cryptography
method at NEC where it had a laser as well as a receiver at one end and
also a mirror at the other end, faced some troubles regarding the high
speed over long distances.
Earlier
the detector that turns the photons to electrons once they collide with
it functioned very slowly. This created a problem in registering these
photons, as there will be an avalanche of electrons with every
collision. The team lead by Tajima has rectified that disadvantage now
by developing a new detector that can work reliably at 100Kbit/s. This
fast pace helps in clearing this whole bunch of electrons produced by
the collision from the device, quickly so that they can register the
next photon. The NEC scientists have also rectified the problem with
the mirror used earlier in the system called the faraday mirror. The
performance of this mirror, which can reflect the light in a 90-degree
rotation from the input light, changes with temperature leading to
quality loss. NEC today has improvised this concept of mirror, by
producing a mirror that works efficiently with temperature variations.
Another
advantage of NEC system is that it has a conventional laser, which can
transmit the photons through the fibre optic cables over a long
distance with very less noise. Although there were powerful lasers that
could trigger the propagation of photons over long distances, they all
resulted in more noises leading to efficiency loss. According to
Nakamura 'This is the world's fastest key generation technology at 40
kilometres'. He confirms his statement with various proofs. He said
that the University of Geneva has achieved quantum transmission over a
distance of over 60 kilometres, but at a much lower speed, while a
system developed by Japan's National Institute of Advanced Industrial
Science and Technology, a major government laboratory, has achieved
nearly the same speed as NEC's system, but only at about half the
distance.
According
to Toshiyuki Kanoh, chief manager of the company's System Platforms
Research Laboratories, this break through system invented in
collaboration with the Japan Science and Technology Agency's
Exploratory Research for Advanced Technology and Japan's National
Institute of Information and Communications Technology, will take an
year to be launched in the commercial market as it’s software is still
on the developing stage. He also added that they are going to create a
commercial market for the system which it lacks now and is expecting
the police, banks and financial institutions etc to be it’s clients by
the mid of 2005. There is also a move to demonstrate this system in
various exhibitions and seminars.
17
Oct 08