Sterlite Technologies Limited (STL), in collaboration with the Centre for Development of Telematics (C-DOT), has announced a significant technological breakthrough—India’s first successful Quantum Key Distribution (QKD) transmission using a 4-core Multi-Core Fibre (MCF) network spanning over 100 km. This pioneering achievement paves the way for a quantum-secured, future-ready communication infrastructure in India.
The demonstration took place under the Department of Telecommunications’ Advanced Optical Communications Test Bed at IIT-Madras, and showcased simultaneous transmission of quantum signals in one core, while three other cores carried high-speed user data—ensuring network security without compromising bandwidth. STL’s MCF cables were deployed both aerially and underground, proving compatibility with real-world infrastructure and compliance with TEC standards.
Quantum communication usually requires a separate dark fibre to protect the delicate quantum signals. However, STL and C-DOT’s integration of QKD with MCF solves this challenge by separating quantum and classical signals within the same fibre. This innovation significantly reduces infrastructure costs and increases data-carrying capacity—key for India’s growing 5G and 6G needs.
Commenting on the milestone, Dr. Rajkumar Upadhyay, CEO of C-DOT, highlighted it as a transformative moment in India’s telecom journey. Rahul Puri, CEO of STL’s Optical Networking Business, added that this showcases the power of public-private partnerships in building a digitally sovereign and secure nation.
With this, STL cements its position as a global leader in optical and quantum communication technologies, advancing India’s strategic digital infrastructure initiatives.
