DRDO, IIT Delhi demonstrate free-space quantum secure communication over 1 km

new delhi: marking a significant leap in india's quantum technology roadmap, the defence research and development organisation (drdo) and iit delhi have successfully demonstrated quantum entanglement-based free-space quantum secure communication over a distance exceeding one kilometre.the milestone, achieved through the drdo-industry-academia centre of excellence (dia-coe) at iit delhi, establishes a secure optical link capable of real-time quantum key distribution (qkd). the experiment recorded a secure key rate of around 240 bits per second with a quantum bit error rate below seven per cent.raksha mantri rajnath singh hailed the breakthrough as a stepping stone towards a new quantum era of secure communications that would be a game changer for future warfare.under drdo's 'design and development of photonic technologies for free space qkd' project, sanctioned by the directorate of futuristic technology management, the demonstration was carried out by prof bhaskar kanseri's team. senior drdo officials and iit delhi leadership were present during the demonstration.quantum entanglement-assisted qkd provides enhanced security compared to conventional methods, as any interception attempt disturbs the quantum state, immediately alerting users. this technology promises robust applications in defence, finance, telecommunications and national security communications, without the need for costly fiber optic infrastructure in difficult terrains.previously, drdo and iit delhi demonstrated india's first intercity quantum link in 2022 and distributed entangled quantum keys over 100 km of optical fiber in 2024.drdo chairman dr samir v kamat and iit delhi director prof rangan banerjee congratulated the team on this landmark feat.