100-kilometre fibre optic cable (IMAGE) Technical University of Denmark Caption The 100-kilometre fibre optic cable through which a team of researchers at DTU has successfully distributed a quantum-encrypted key securely. Photo: DTU Credit DTU Usage Restrictions To be used only in relation to this particular story. For all other uses please contact press@dtu.dk. License Original 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.