The Next Internet is Quantum

What Is the Quantum Internet?

The quantum internet is a vision of future networks that connect quantum devices "like quantum computers or sensors" using quantum-entanglement. This creates links where any eavesdropping attempt disturbs the delicate quantum states, instantly flagging an intrusion. This transforms data transmission into a fundamentally tamper-evident process.

India's Recent Breakthrough with DRDO & IIT‑Delhi

On June 16, 2025, DRDO and IIT‑Delhi achieved a landmark demonstration: free‑space entanglement-based quantum key distribution (QKD) across more than 1 km without using fiber, achieving ~240 bits/sec key rate and a quantum bit error rate below 7 %

• This improves upon previous milestones:
  • A 100 km fiber-based entanglement QKD in 2024.
  • India’s 2022 fiber QKD link (Vindhyachal–Prayagraj). This live free-space test proves QKD can work in challenging urban terrains without laying fiber—a critical step toward city-to-city quantum networking.

Test-Bed Configuration and Optical Line-of-Sight for Free-Space Quantum Key Distribution Experiment Conducted at IIT Delhi

Why It Matters: The "Why" Behind the Hype

🔒 Unbreakable Security

Any interception collapses quantum entanglement, immediately signaling tampering—offering provable protection against even future quantum computers

🏙️ Infrastructure Flexibility

Free-space QKD bypasses terrains and cost barriers of fiber deployment—ideal for cities, hilly areas, or military operations.

🌍 Network Expansion

Combining free-space optical links, existing fiber, and satellite QKD can eventually form a global quantum network, secured end-to-end

Tech Behind the Scenes

Building a quantum internet requires two key technologies:

• Entanglement-Based QKD: Photons are entangled, and shared random bits are distilled into cryptographic keys. Any disturbance alerts users
• Quantum Repeaters & Satellite Links: Given photon loss, repeaters (akin to classical boosters) or satellite relays are vital for long-distance distribution

Future Use-Cases & Visionary Applications

• Nationwide Secure Communication: Encrypted military, government, and finance data secured via QKD keys.
• Distributed Quantum Computing: Remote quantum nodes linked securely to create hybrid compute clusters
• Next‑Gen Science & AI: Quantum networks could support high-precision sensors, real-time simulations, and AI-driven discoveries.
• Global Quantum Infrastructure: By combining terrestrial and satellite QKD, a secure quantum backbone spans continents