India has made a significant breakthrough in quantum communication by successfully demonstrating quantum entanglement-based free-space secure communication over a distance exceeding one kilometre. This achievement, accomplished by the Defence Research and Development Organisation (DRDO) in collaboration with IIT Delhi’s DRDO-Industry-Academia Centre of Excellence (DIA-CoE), marks a major step forward in quantum cybersecurity and the future of secure communications. The experimental setup was established on the IIT Delhi campus, where researchers used a free-space optical link to transmit quantum keys based on the phenomenon of quantum entanglement. The demonstration achieved a secure key rate close to 240 bits per second with a quantum bit error rate of less than 7%, highlighting the robustness and practical feasibility of this advanced technology. Quantum entanglement is a unique property of quantum particles, where two or more particles become linked so that the state of one instantly influences the state of the other, regardless of the distance between them. This phenomenon allows for the creation of encryption keys that are fundamentally secure. Any attempt by an unauthorised party to intercept or measure the entangled photons disrupts their quantum state, immediately alerting legitimate users to eavesdropping attempts.

Full report : India achieves quantum entanglement-based secure communication over one KM.