  One of the obstacles to deployment of QKD solutions has been the distance
limitation. Solutions using relays have been proposed but these rely on
link-by-link key establishment. We present a new technique to extend the
distance of a quantum key distribution channel using an active relay. Each
relay acts as an intercept/resend device and allows the establishment of an
end-to-end key. It has been argued that such relays cannot be used to extend
the distance, but we show that with a suitable adaptation of the protocol the
effective key distribution distance can be increased.
