THEMATIC HUB
Quantum Communication
IIT Madras (with C-DOT) · Chennai
Securing India's communications against future quantum attacks through terrestrial QKD networks, satellite links, and post-quantum cryptography under the IITM C-DOT Samgnya Technologies Foundation.
What this hub does
Mandate, technical execution model, and operational research scope.
Encryption in wide use today can eventually be broken by a powerful enough quantum computer. This hub is building two different defences: physics-based Quantum Key Distribution (QKD) and mathematical Post-Quantum Cryptography (PQC).
Incorporated at the IIT Madras Research Park in partnership with the Centre for Development of Telematics (C-DOT), the hub coordinates terrestrial dark-fiber links, free-space links, and satellite quantum payloads.
QKD, post-quantum cryptography, and a quantum internet are different
Quantum key distribution (QKD) uses quantum physics to generate keys that reveal an eavesdropper. It secures a link.
Post-quantum cryptography (PQC) uses new classical algorithms designed to resist quantum attacks. It secures software everywhere else.
A long QKD network is a major step. It is not a quantum internet. That also needs quantum memories, repeaters, and entanglement distribution, and none of those are solved.
Goals
Performance targets and technical delivery milestones.
Target is an aim. Reported is a public claim. Demonstrated has been shown working. Deployed is in service.
- Target
Satellite-based secure quantum communication between Indian ground stations, over about 2,000 km.
- Target
Inter-city quantum key distribution over about 2,000 km connecting major financial and administrative corridors.
- Target
Multi-node quantum networks using trusted repeaters.
- Target
Long-distance secure quantum communication with partner countries.
- Target
Quantum memories and quantum repeaters, the enabling technologies for long-distance entanglement distribution.
Technology platforms
Concurrent hardware modalities and engineering approaches.
Named in the India Quantum Alliance's current scope. Each of these is a target, not a deployed system.
Continuous-variable QKD (CV-QKD)
In development.
Measurement-device-independent QKD (MDI-QKD)
In development. Meant to close detector side channels.
Twin-field QKD
In development.
Chip-based QKD
In development.
Quantum-secure direct communication
In development.
Superdense coding
In development.
Quantum teleportation
In development.
Participating network
Academic hubs, national institutes, and partner research centres.
Anchored at the IIT Madras Research Park under the IITM C-DOT Samgnya Technologies Foundation in partnership with national defense, space, and telecom agencies.
- IIT Madras
- C-DOT New Delhi
- Space Applications Centre (SAC-ISRO)
- Raman Research Institute (RRI)
- DRDO (DYSL-QT)
- SETS Chennai
- IIT Delhi
- IIT Bombay
- C-DAC Bengaluru
- Physical Research Laboratory (PRL)
- Army Quantum Lab (MCTE Mhow)
- Telecommunication Engineering Centre (TEC)
Technical groups
Designated research task groups established under government sanction.
Three national technical groups coordinating terrestrial fiber QKD, space-to-ground satellite links, and post-quantum cryptography standards under the Samgnya Technologies Foundation.
Terrestrial Dark-Fiber QKD & Trusted Nodes
Continuous-Variable (CV-QKD) and Decoy-State COW/DPS protocols over terrestrial dark fiber exceeding 100–500 km, optical distribution frames, and TEC 91000:2022 telecom standard integration.
Satellite & Free-Space Optical Quantum Links
Free-space optical transceivers, PAT (Pointing, Acquisition, Tracking) gimbals, and low-Earth orbit satellite payloads under the ISRO SAQTI pathfinder mission for 2,000+ km space-to-ground key distribution.
Quantum Repeaters, Memories & Post-Quantum Cryptography (PQC)
Solid-state quantum memory development, trusted repeaters, and phased transition of national financial/defense infrastructure (UPI, Aadhaar) to hybrid classical/PQC standards (ML-KEM, ML-DSA).
Milestones & Standards
Field trials, published standards, and validated hardware benchmarks.
- Reported
Government reporting describes a quantum communication network of about 1,000 km, shown in April 2026.
It used indigenous technology from QNu Labs, an NQM-supported startup. The government has described it as one of the world's longer QKD deployments.
- Demonstrated
Indian Army Southern Command Signals and QNu Labs demonstrated a 500 km multi-node QKD network across Rajasthan.
Announced in November 2025 at ESTIC, the network utilized QNu Labs' Quantum Suraksha Kavach (QSK) rack over operational defense dark-fiber infrastructure with trusted nodes.
- Demonstrated
DRDO and IIT Delhi validated continuous QKD over a 100+ km dark-fiber link between Prayagraj and Vindhyachal.
Demonstrated in February 2022 using existing commercial dark fiber, achieving sifted key rates up to 10 KHz.
- Demonstrated
ISRO demonstrated free-space QKD over 300 metres at the Space Applications Centre, Ahmedabad.
The setup used a NAVIC receiver for timing, gimbal-based optical alignment, and live video conferencing encrypted with a quantum key.
- Deployed
C-DOT's indigenous QKD system operates on standard single-mode fibre with TEC technology approval.
Compliant with TEC GR 91000:2022. Supports DPS and COW protocols with QRNG and TRNG options, REST key APIs, and integration with 100G/200G telecom equipment.
- Deployed
National Telecom Engineering Centre (TEC) published standards suite for quantum communication.
Published specifications include TEC GR 91000:2022 (QKD Systems), TEC 91001:2023 (QKD Test Guide), TEC 91010:2023 (Quantum-Safe & Classical Cryptographic Systems), TEC 91020:2024 (QRNG), and TEC 910018:2025 (PQC Migration).
- Target
ISRO SAQTI pathfinder LEO satellite mission for space-to-ground quantum communications.
Secured Applications using Quantum and optical Technologies (SAQTI) payload led by SAC-ISRO and RRI to validate intercontinental satellite-to-ground QKD across 2,000+ km.
Startups
Domestic deep-tech enterprises and commercialization grantees.
- QNu Labs
NQM-supported. QNu Labs' Armos (QKD) and Tropos (QRNG) hardware is listed on the Government e-Marketplace (GeM) for public procurement.
Applications
Downstream defense, industrial, and strategic mission impact.
- Defence communications
- Financial systems & interbank RTGS
- Critical infrastructure & grid SCADA
- Government encrypted telephony
- Telecom backbone security
Open challenges
Fundamental scientific and supply-chain hurdles confronting scale.
- Quantum memories
- Repeaters
- Long-distance entanglement
- Loss management
- Network synchronisation
- Moving beyond trusted-node architectures
Hub news
Recent developments, research papers, and dispatches.
The live India feed has fewer than two stories that match this hub. Curated references are listed with anything that did match.
Curated reference
Finance Minister Sitharaman Identifies Quantum, AI, and Semiconductors as Pillars of India's Infrastructure Evolution
Sources
Departmental notifications and verification records.