Quantum secure communications are a must for India, officials say

Senior government officials on Friday (April 25, 2025) stressed the importance of developing and deploying quantum-secure communications, using encryption that will withstand any future developments in the next generation of advanced computer systems.

Under the National Quantum Mission (NQM), one of the four pillars is quantum communications, which focuses on indigenously developing such capabilities.

“If you have a 128-bit AES [Advanced Encryption Standard] system, it cannot be decrypted in your lifetime, because the number which is getting factorised is very large,” Ajay Kumar Sood, India’s Principal Scientific Advisor said. Dr. Sood was referring to the cryptographical techniques used to encrypt data, which typically involve one-way mathematical functions to encrypt information in digital systems. Using mathematical functions like this is extremely difficult to decrypt without a key.

However, quantum computers – which rely on qubits as opposed to classical computers that use binary, have shown great theoretical promise in attacking such decryption tasks. Qubits leverage aspects of quantum mechanics that may allow them in the future to decrypt data that would take regular supercomputers several years in a fraction of that time. Since quantum computers are at a nascent stage of development – qubits are proving difficult to leverage in a large enough group – these capabilities have not yet emerged. But policymakers worldwide are preparing for their arrival.

When “quantum computers are available, this [decryption] can be done in probably a few minutes provided we have enough qubits, and the noise in those qubits is limited,” Dr. Sood said. “And this is where the entire world is going. Imagine if that happens. None of our transactions will be safe. None. And this is where it is a strategic autonomy issue that quantum technologies have to be developed in our country. So, it is not a choice, it is a must.”

While quantum decryption still requires significant scientific leaps, quantum-resistant encryption techniques have already seen significant progress. India’s goal under the communications pillar of the NQM is “ensuring secure quantum communication over 2000 km,” Union Minister for Communications Jyotiraditya Scindia said.

Quantum key distribution (QKD), a protocol that requires the distribution of encryption keys across a long distance – a challenging undertaking – has seen progress. Mr. Scindia pointed to a recent deployment of QKD between two cities in Germany, for a distance of 254 km, along existing telecom equipment.

“When you are transmitting the encryption key through photons, there needs to be cryogenically induced mechanisms to keep that system cool to be able to transmit over distances,” Mr. Scindia said. “But this [deployment in Germany] has been done using traditional optical fibre cables and traditional computers.”

Some deployments are already being tested. The Konark Corps of the Indian Army, for instance, said on April 13 that it had successfully demonstrated quantum secure key distribution in “field conditions” in Jodhpur. Government bodies like the DoT’s Telecom Engineering Centre and startups demonstrated their own implementations of quantum-resilient applications at the conclave as well.