In our digital world, randomness is more important than most of us realise. It is the invisible lock that keeps our bank transactions safe, shields private conversations and guards sensitive data online. Without randomness, encryption would collapse, and hackers could easily guess patterns hidden behind passwords and security codes. The problem is that ordinary computers cannot create real randomness. Their so-called random numbers are produced using fixed instructions, which means that, in principle, they can be predicted.
This is where the strange world of quantum physics steps in. Unlike the predictable logic of machines, quantum mechanics is fundamentally uncertain. Events in this realm, like how a photon behaves or how a qubit evolves, cannot be perfectly foretold. If harnessed properly, this unpredictability can produce genuine randomness, a resource that cannot be hacked or reverse-engineered.
Over the last three years, researchers at the Raman Research Institute (RRI) in Bengaluru, supported by the Department of Science and Technology (DST), have been steadily proving that this dream can be turned into reality. What began as a purely scientific search into the foundations of physics has now matured into a working technology capable of producing “certified quantum randomness.” This is randomness guaranteed by the laws of nature itself, not by man-made algorithms.
From foundations to device making
The journey started in 2022, when the team at RRI set out to answer a big question: Is our world ultimately classical and predictable, or does it truly obey the counterintuitive rules of quantum mechanics? To test this problem, they used single particles of light called photons and studied their behaviour over time. The key was a set of mathematical checks known as Leggett-Garg inequalities. If these inequalities are violated, it means the world does not follow classical rules; it follows quantum ones.
The RRI experiment closed every possible loophole that might point to building a loophole-free photonic architecture. For the first time, they could decisively show that time-correlated measurements on photons prove the world is indeed quantum at its core. This wasn’t just another physics paper; it laid the groundwork for the practical aspects of qubit.
In 2024, the team turned this foundational success into a working device, a quantum random number generator. Unlike standard generators inside laptops or phones, this one produced random bit, millions of them at a time with their unpredictability certified by quantum laws. Think of it as tossing a digital coin a million times, each flip completely unguessable yet probably random. For industries that depend on ultra-secure communication, this was a game-changing breakthrough.
In 2025, the RRI group collaborated with the Indian Institute of Science and the University of Calgary and demonstrated that certified quantum randomness did not need expensive labs filled with lasers, mirrors and delicate optical tables. Instead, it could be realised on a general-purpose quantum computer that anyone could access through the cloud.
For years, certified randomness had been generated only in elaborate research facilities, often using entangled particles spread across space. Such methods are groundbreaking and were far too complex to be practical outside physics labs. The new idea was refreshingly simple, instead of separating particles in space and uses time as the key ingredient.
By performing continuous single-qubit observation of the smallest building block of a quantum computer at different moments, the researchers were able to extract genuine randomness. These time-based measurements bypassed the need for entanglement across large distances. This method worked on the IBM superconducting qubit platform, a cloud-accessible quantum processor. In short, anyone with internet access and the right tools could tap the power of certified randomness.
Why this matters for future of India
“The simplicity of this approach is precisely what makes it powerful,” said Pingal Pratyush Nath, a PhD student at IISc involved in the work. By showing that even small and noisy quantum processors can create randomness guaranteed by the laws of physics, the team opened the doors to a wide range of applications.
Certified randomness is integral for cryptography, especially for the plausibly secure systems where digital keys must remain unconditionally unguessable, and this research makes it plausible for such protocols to be executed on a quantum device easily. Digital keys, which lock our emails and protect bank data, rely on random numbers. But if those numbers come from predictable algorithms, the locks are not as strong as they appear. Certified quantum randomness ensures these keys are unbreakable because they are born from nature’s deepest uncertainty. There is another hidden benefit, too. By testing qubits through time-based measurements, researchers gain a practical way to check how reliable a quantum computer’s hardware is. It is like running a health check on the qubits themselves, ensuring that the machine is performing to the precision required.
A benchmark for reality
The achievement goes beyond technology. By proving that certified randomness can emerge both in specialised optical setups and in commercial quantum processors, the researchers have underlined a profound fact about the universe itself: reality is truly quantum, and its unpredictability can be tapped for human use.
The implications are enormous. Imagine secure video calls where the encryption keys cannot be cracked by even the most powerful supercomputers. Picture financial systems shielded by randomness that no hacker can predict. Consider defence communications guarded not by human-made algorithms but by the indeterminacy of the universe itself.
By transforming certified quantum randomness from a laboratory curiosity into a resource anyone can access, the RRI-led team has set the stage for a new era of digital security. They have also provided a powerful new benchmark for testing and validating quantum machines worldwide.
It is a rare achievement when science manages to be both deeply philosophical and highly practical. This research does exactly that. On the one hand, it confirms that our universe dances to the tune of quantum mechanics. On the other hand, it delivers tools that will soon protect our daily lives from online banking to private messaging.
As the journey continues, one thing is clear: randomness, once seen as a nuisance or mystery, has become one of the most valuable resources of the quantum age. And thanks to the work of Indian scientists along with their global collaborators, it is now something we can all access securely, through the cloud.
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