Efforts are being made to build the first quantum computer. Quantum computer is a machine far more powerful than today’s computers. Quantum computing is based on quantum mechanics — the science that explains the strange behaviour exhibited by extremely small particles of matter.

In traditional computers transistors store ‘bits’ of information and each bit is either a 1 or a O. Those are the fundamental slices of data that tell a computer what to do.

Some types of matter, when they are extremely small or extremely cold, behave differently. That difference allows a quantum bit ( qubit) to store a combination of 1 and O. Thus these sub-atomic particles exist in two different states simultaneously. Qubits achieve a mixed state called superposition. This ambiguity or the ability to be and not be is the key to the power of quantum computing. Two qubits can hold four values at once. As the number of qubits grows, a quantum computer becomes exponentially more powerful.

Qubit could be considered as an electron into a magnetic field. It could be in alignment with the field, called spin-up state or opposite to the field, called sin-down state. Each qubit could take a superpostion of both 0 and 1.

Quantum computer could break the encryption that protects digital information. The whole e-commerce and government data bases are at risk. Therefore simultaneously, researchers are working on quantum security techniques. These techniques would thwart the code breaking abilities of the quantum computers. China has a clear lead in quantum encryption.

Quantum encryption too relies on the non-intuitive behaviour of very small objects. The codes that keep data secret are sent by photons. With the right equipment, it is easy to tell if they have been tempered with or not.

A visible quantum encryption network cannot be built over long distances. However, there are experiments in this direction. There is quantum communication network between Beijing and Shanghai. They want the Chinese built networks to spread across the world. Quantum networks cut the number of vulnerable spots to a few dozens.

Apart from this, mathematicians are working on new forms of encryption that can stand up to a quantum computer by using mathematics. Here we do not need a new infrastructure.