India Pushes Boundaries in Quantum Communication With Key Entanglement Test

Published: 24 Jun 2025

Author: Precedence Research

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India has contributed a major transformation in the quantum communication sector by performing 1 km quantum entanglement-based quantum key distributions over free space, according to a statement issued by the country’s Ministry of Defense. The experiment was performed by the DRDO-Industry-Academia Center of Excellence at IIT Delhi. 

The experiment achieved a secure key rate of nearly 240 bits per sec while keeping a quantum bit error rate of less than 7%. This test is considered a stepping stone for India's quantum sector journey. The free space showcases the non-requirement of fiber optic cables and offers new possibilities to expand into quantum technology and secure communication with the help of quantum entanglement. 

The experimental set-up that is used for this process, any kind of interruption attempt during the communication process, sends alerts by detecting changes in the quantum state, which makes the user alert for potential data breaches within the system at the same time, avoiding further losses. This method, known as entanglement-assisted quantum key distribution-QKD, offers a higher level of security than conventional techniques.  

As per the official statement, the experiment was conducted with the intent of supporting future applications in defense, telecommunication, and finance that will provide highly reliable, secure communication links. That experiment was essential to developing photonic technologies for free space QKD. 

• In 2022, DRDO scientists and Professor Kanseri’s team will show the nation’s first intercity quantum link over underground fiber, located between Prayagraj and Vindhyachal. In 2024, the same group performed another experiment by distributing quantum keys across 100 km of telecom-grade optical fiber, strengthening quantum secure communication over existing infrastructure. 

According to sources, this recent free space test surpasses the requirements for fiber installations as it can be overly expensive and may create barriers to adopting this technology, especially in remote or underserved areas. The team has offered a proof-of-concept that could scale to longer distances and be able to adapt to mobile applications and satellite-based systems by performing secure transmission in the Air Medium. 
This work has been carried out with the cooperation of DIA-CoEs research hubs backed by DRDO at the top Indian institutes like IISCs and IITs. These centers help develop high-end defense technologies by collaborating with government, academia, and industry.