Fact Check: India's quantum key distribution spans 100 km using entanglement!

Fact Check: "India's quantum key distribution spans 100 km using entanglement!"

What We Know

India has made significant advancements in quantum communication, particularly through a collaboration between the Defence Research and Development Organisation (DRDO) and the Indian Institute of Technology (IIT) Delhi. Recent reports indicate that they successfully demonstrated quantum entanglement-based secure communication over a distance exceeding one kilometer using a free-space optical link on the IIT Delhi campus. This experiment achieved a secure key rate of approximately 240 bits per second with a quantum bit error rate of less than 7% (source-1, source-5).

Moreover, in 2024, the same team reportedly extended their quantum key distribution capabilities by successfully distributing quantum keys over a distance of 100 kilometers using a spool of telecom-grade optical fiber (source-1, source-6). This achievement is part of a broader initiative to develop quantum technologies for national security and cyber defense (source-2).

Analysis

The claim that "India's quantum key distribution spans 100 km using entanglement" is based on two separate achievements: the successful demonstration of quantum entanglement communication over one kilometer and the distribution of quantum keys over 100 kilometers using telecom-grade optical fiber.

One Kilometer Demonstration: The initial experiment confirmed the feasibility of quantum entanglement for secure communication over a distance of more than one kilometer. This is a critical step in establishing the practicality of quantum key distribution (QKD) systems (source-1, source-4).
100 Kilometers Achievement: The later achievement of distributing quantum keys over 100 kilometers is significant but does not directly involve quantum entanglement in the same manner as the one-kilometer demonstration. Instead, it utilizes telecom-grade optical fiber, which is a different medium compared to the free-space optical link used in the earlier experiment (source-6, source-7).

The sources cited are credible, coming from reputable institutions like DRDO and IIT Delhi, as well as established news outlets. However, the distinction between the two methods (free-space vs. fiber-optic) is crucial for understanding the scope of the claim.

Conclusion

The claim that "India's quantum key distribution spans 100 km using entanglement" is Partially True. While India has indeed achieved quantum key distribution over 100 kilometers, this specific achievement does not utilize quantum entanglement in the same way as the one-kilometer demonstration. Therefore, while the claim highlights significant advancements in quantum communication, it conflates two distinct methods of achieving secure communication.