Even when they were developing MISTY, Mitsuru Matsui and his team already envisaged a world in which everyone would access networks. And technology has progressed just as they thought it would, although faster than they had imagined. No more than ten years has passed but already ubiquitous networks are waiting in the wings to become part of our daily lives. Encryption and other security technologies have become essential to the devices, systems and business models on which our daily lives depend, on which companies depend, and on which the social infrastructure depends.

No doubt Mitsubishi Electric’s future mission will be to find fresh solutions for the multiplying number of fields in which security issues are becoming important. As a comprehensive electrical appliance manufacturer, Mitsubishi Electric has the needed hardware/systems technologies - from chips and electronic components to electrical appliances, car parts, industrial systems and satellite communications - the IT expertise, from networks and software to system integration, and also extensive business experience covering everything from finance, manufacturing and distribution to public services. A company with resources of such breadth and depth has an important role to play in seeing that the future network society is one in which we can all enjoy peace of mind.

The challenge continues. But before bringing this series to an end, let’s take a look at the latest developments in the world of encryption.

First, let’s examine something that constitutes a threat to all current encryption technologies, including MISTY: quantum computing. A quantum computer is based on quantum mechanics, something completely alien to the principles of conventional computing. This will be the ultimate computer: employing a phenomenon observed only at the level of subatomic particles, known as “superposition,” a quantum computer will be able to instantly calculate thousands of permutations. In effect, this will mean that it can perform lightning-fast mathematical calculations at speeds that are unimaginable with current computers. Unfortunately, the strength of today’s encryption systems rests on the simple fact that it would take too long, using conventional computers, to break a code using “brute force” - that is, by calculating all of the possible permutations. But as soon as quantum computing emerges from the laboratories where it is being developed, these encryption systems will be wide open to attack. The very basis for their security will vanish overnight.

What can be done? Will no information be safe? Fortunately, the very theory that makes quantum computing possible - and thus current encryption systems vulnerable - offers at the same time a new form of security: quantum cryptography. Quantum cryptography makes use of the Heisenberg Uncertainty Principle. With something as small as a subatomic particle, the very act of observing it will affect it - that is, its state will change. In other words, unlike all conventional encryption systems, which seek to be unbreakable, quantum cryptography is simply a system to make eavesdropping impossible.

Quantum cryptography was first propounded in 1984.At present, companies and research institutes around the world are vying to be the first to come up with a practical implementation. This is in fact another field in which Mitsubishi Electric is one step ahead. The secret to implementing quantum cryptography is the use of current optical fibre networks. Mitsubishi Electric has developed quantum-level technology that enables the detection of single photons travelling through a long-distance fibre-optic communications link. This has made possible the successful implementation of quantum cryptography over a distance of 87 kilometres (equivalent to the distance between Tokyo and Mount Fuji), a world record. Moreover, by combining quantum cryptography with current encryption technologies like MISTY, it will be possible to offer high-speed performance as well as preventing eavesdropping. This will be of immense importance for applications that demand maximum security, such as in finance and public services, diplomacy and national defence. Quantum cryptography has taken the first step towards offering a practical solution.

Aiming to create a network society that is safer and more convenient, Mitsubishi Electric’s encryption technologies are changing the 21st century for the better.