Secure communications are vital for defense and strategic agencies all over the world and distribution of encryption keys from time to time is an important requirement in this context. Sharing of keys over the air or through wired links requires encryption, which in turn requires encryption keys to be pre-shared. Quantum based communication offers a robust solution to sharing the keys securely. The Indian Defence Research & Development Organisation (DRDO) developed a Quantum Key Distribution (QKD) technology that underwent trials in Hyderabad, India between two DRDO labs, DRDL and RCI, to show secure communication.
The technology is developed by CAIR, Bengaluru and DYSL-QT, Mumbai in India. Quantum Communication using a time-bin Quantum Key Distribution (QKD) scheme was performed under realistic conditions. The setup also demonstrated the validation of detection of a third party trying to gain knowledge of the communication. Quantum based security against eavesdropping was validated for the deployed system at a distance of over 12 kms and 10 dB attenuation over a fibre optic channel.
A Continuous wave laser source was used to generate photons without depolarization effect. The timing accuracy employed in the setup was in the order of picoseconds. The Single photon avalanche detector (SPAD) recorded arrival of photons and the key rate was achieved in the range of kbps with low Quantum bit error rate. Software was developed for data acquisition, time synchronization, post-processing, determining Quantum bit error rate and extracting other important parameters.
The work being done at DRDO will be used to enable start-ups and SMEs in the domain of Quantum information technologies. It will also serve to define standards and crypto policies that can leverage QKD system in a unified Cipher Policy Committee (CPC) framework for more secure and pragmatic key management for current and future military cryptographic systems.
