# Prepare for a world of quantum haves and have-nots

*Google’s recent achievement of “quantum supremacy” has highlighted the urgency of commercializing quantum computing. Once viable, it will render current encryption methods obsolete, as quantum computers could easily defeat even the highest encryption. India must invest in quantum computing research and development to remain technologically relevant and independent in the future.*

*This article was first published in The Mint. You can read the original at this link.*

More than two years ago, the department of science and technology launched the Quantum-Enabled Science and Technology (QuEST) programme with an aim to develop technical capacity within the country to build quantum computers and communications systems comparable with the best in the world. The first phase of the project was to build the infrastructure and acquire human resources to develop physical and computation structures for improving precision in quantum measurement. The eventual goal is to build quantum computers domestically.

Though the allocation in this year’s budget is clearly part of a long-term national strategy, I cannot help wonder whether it is, at least in some small measure, a response to Google’s recent announcement that it had achieved “quantum supremacy”—the ability to perform a calculation on a quantum computer that is impossible on a conventional computer. And the fear that we might, once again, be falling behind.

As much as I enjoy science, quantum mechanics gives me a headache. Quantum computing is an order of magnitude more perplexing. Ordinary computers function using binary logic gates that can be either off or on. This is why classical computers store information in bits—either as a 0 or 1. On the other hand, [[quantum computers]] can store information as both a 0 and a 1 at the same time using a quantum property called superposition. This means that with two quantum bits (or qubits), information can be stored in four possible states of superposition, and as more qubits are added, the computational power grows exponentially.

While this gives us more computing power, quantum computers are error-prone. The quantum state is delicate. It lasts for a fraction of a second and is easily disrupted by tiniest of vibrations or variations in temperature. This “noise” in calculations causes mistakes to occur, and unless we can make them sufficiently error-free, quantum computing will not be commercially viable. Google’s breakthrough was to achieve sufficient control over the process to allow its experimental computer to outperform a traditional computer. As a result, its computer could solve in 200 seconds what would take the world’s fastest supercomputer 10,000 years.

We still have a long way to go before quantum computing becomes commercially viable, but there is reason for urgency. As soon as quantum computing becomes commercially viable, much of what we take for granted today will become irrelevant.

Take encryption, for example. Almost all digital security today is based on the RSA algorithm that encrypts messages by relying on the factorization of two large prime numbers. While it is easy to multiply two prime numbers, it is very difficult to factorize them. RSA encryption exploits this feature, making it impossible for even governments and private actors with near infinite computational resources to decrypt messages. This is why we have the confidence to store valuable information in encrypted archives on the cloud, secure in the knowledge that even the largest corporations and most technologically advanced governments don’t have the computational capability to decrypt these databases and access the information stored inside.

Once quantum computers are capable of being used for decryption, the computational hurdles of prime number factorization that we now rely on will become trivial to overcome. Shor’s algorithm already describes a process by which quantum computers could be used find the prime factors of any integer. In 2001, IBM proved that this algorithm works by using a 7 qubit computer to factorize the number 15 into 5 and 3. Google’s Sycamore processor harnessed 53 qubits in its latest experiment, demonstrating that much higher computational capabilities are already within our grasp. Once our quantum computers have reached a sufficiently advanced level of stability, even the highest encryption known to man will be easy to defeat.

When that happens, cyber security as we know it will be a thing of the past. All the secure data services that we rely on will be thrown wide open, allowing anyone with a quantum computer to easily access the information within. Given the imminence of major breakthroughs in quantum computing, it is rumoured that there is already an underground market for encrypted data in anticipation of a time when all this information can be decrypted and the secrets of famous personalities can be exposed.

In the war for quantum supremacy, it is those who can understand and use the fundamental technologies behind quantum computing who will emerge dominant. In the not-so-distant future, the world will be divided into the quantum haves and have-nots. It is imperative that India makes every effort to stay in the game if it is to have any hope of remaining relevant. If we are to retain any measure of technological independence, we will need to ramp up our research in quantum computing and actively invest in the development of indigenous quantum computational capabilities.