A LOCAL pub played its part in a groundbreaking DERA experiment which could pave the way for a communications system which cannot be bugged.

Scientists visited the Wyche Inn, to send single photons - the fundamental particles of light - back to DERA's main base.

The successful experiment, carried out in December but only announced this week, means the DERA team now hold the world record for transmitting pulsed polarised single photons over a distance of 1.9 km.

It brings a step nearer the prospect of quantum cryptography, which could lead to unbreakable codes for communications.

The theory of quantum cryptography is well established, but DERA's optical communications team are among the first to demonstrate a working system.

Prof John Rarity, one of the team, said: "We chose the Wyche Inn because it was in a good position overlooking DERA and it was raised up so it would avoid ground turbulence.

"We rented a room and we had to wait until 11.30pm for the lights to go out."

The team plans to follow up its success with transmissions over progressively longer distances, culminating in a UK-USA satellite link-up. The photon signals sent would form the key for a new form of encryption, which would be unbreakable.

Prof Rarity said: "The encryption people use today, such as Pretty Good Privacy, is secure now but as computation techniques develop over the next 10-15 years, it may become vulnerable."