The Defence Research & Development Organisation (DRDO) and IIT Delhi have together achieved a rare technological feat that enables secure communication using quantum mechanics. It paves the way for deploying real-time applications in cyber security, development of quantum networks and reliable communication without using fibres. According to the defence ministry, secure communication over a distance of more than 1 km was achieved via an optical link established on the IIT Delhi campus under a project sanctioned by DRDO’s Directorate of Futuristic Technology Management. The technology bypasses the need for optical fibres that are cumbersome and expensive to lay in dense urban environments and challenging terrains.
The experiment involved free-space quantum key distribution (QKD), which allows two communicating parties to generate and share a secret random key to encrypt and decrypt messages. QKD relies on quantum mechanics to make it more secure than traditional cryptographic methods. The process is based on quantum entanglement, in which multiple particles (photons and electrons) get linked. This interconnectedness is the core concept in quantum communication, enabling secure data transmission. Any attempt to measure or intercept the entangled photons disturbs the quantum state and allows authorised users to detect the presence of eavesdroppers, besides instantly alerting the sender and the receiver.
However, while it promises cyber security with unbreakable encryption and applications in securing data in strategic sectors of defence, telecommunications, finance, besides protecting national security-related communications, much more needs to be done. India is still in the early stages of quantum communication, in which China has taken the lead globally. China has the world’s largest quantum communication network of a length of 12,000 km, which includes two quantum satellites—Micius and Jinan-1—providing space-to-ground QKD segment facilitating secure links between ground stations 1,200 km apart.
India’s efforts at establishing and expanding quantum communication network need a boost through the string of centres of excellence set up in premier academic institutions by the DRDO-industry-academia troika for developing cuttingedge technologies. The efforts need to be guided to develop technologies that can make cyber networking and communication quicker and significantly more secure—for both civilian and military usage.