To break a standard public RSA encryption code involves testing large numbers that with General Purpose Computing (GPC) or even a super computer would take a number of years equivalent to the half-life of the universe.

Quantum computing would be a viable alternative, said Joseph Reger, Chief Technology Officer, Fujitsu Fellow, Fujitsu. Why? Because quantum computing lets you computing various possibilities at the same time, not sequentially.

Duality is key to quantum physics: light is a wave; light is also a particle, and particles can behave like waves. Quantum effects are so small that they can only be seen on a microscopic atomic scale.

Quantum theory is a probabilistic system, and the solutions it produces are waves of probability. Our transistors have become so small that the writing is on the wall for the deterministic nature of classical computing.

In the quantum space, functions combine and systems can be in all possible quantum states in a combination at the same time, and they evolve together at the same time. So, we can deal with all possibilities not sequentially, but at the same time giving us enormous computing power. When we measure the system though, we interact with the system, even by just reading it, and it then collapses into one of the classical states. That’s why, error correction is one of the big challenges of quantum computing.

Superposition and entanglement, two key principles of quantum computing, give us incredible speed up, and catapult us forward by a huge number of years.

### Why don’t we just simulate this on classical computers?

We would need a huge computer the size of the universe to do it and it would need the age of the universe to perform the necessary calculations; we need to build quantum hardware: quantum gate computers. The key challenge is to keep the quantum computers in the quantum state for long enough for a meaningful measurement. Quantum gate computers are very desirable, but very hard to build: only one commercially used quantum computer exists. Once we have the relevant algorithms, RSA encryption will be useless.

We can do quantum annealing which uses quantum tunneling, and this is how the only commercial quantum computer in the world works.

Why don’t we apply the lessons of quantum mechanics in a hardware that uses some of the tricks of quantum mechanics? Dr. Hirotaka Tamura, Fellow, Fujitsu Laboratories, introduced the Fujitsu Digital Annealer (DA). It’s not a quantum computer but quantum inspired, and it can be used for combinatorial problems. It brings many benefits of quantum annealing, but is based on standard digital technology. The DA has 1024 bits, but has full connectivity to other bits so resembling quantum mechanics. Fujitsu is working with partners like Canadian start-up 1Qbit and with the University of Toronto for the software development. In the future, the DA will be 100000 times faster than conventional processors; right now, it’s 17000 faster than conventional processors. By taking Moore’s law, 17000 faster means 14 generations. This means that Fujitsu’s DA beams us ahead by 14 generations.

We can do disaster management and mitigations, molecular research, radiation therapy in the human body and much better models of machine learning and artificial intelligence. As quantum states cannot be copied, quantum networks are safe.

Until quantum computing is available to all, Fujitsu’s Digital Annealer can be used to build a better, safer more prosperous world for all. The future is much brighter with Quantum Computing.