QKD Transmitter (IMAGE) Optica Caption The entire transmitter for the new QKD system fits in a 19-inch rack enclosure, which is commonly found in server rooms. Credit Luca Calderaro, Università degli Studi di Padova Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.