A Brief Introduction to Quantum Computing

What are quantum computers?

Quantum computers are faster and more efficient than current computing approaches. In classical computers, bits can only exist in one of two states: a 1 or a 0. Quantum mechanics allows for a third state, a superposition of 0 and 1 where the bit is both 0 and 1 at the same time, meaning these quantum bits (qubits) can exist in multiple different combinations at once. If a computer consisted of four bits, for example, the computer can only exist in one of 16 states at a time, while a quantum computer could exist in all 16 at the same time. This fact indicates just how much faster a quantum computer could carry out processes.

Although large technology companies such as IBM, Microsoft and Intel are now building quantum computers prototypes, quantum computers will not be public for a time due to the security concerns that arise from the existence of near-instant computing. Passwords, for instance, could be compromised. Brute force hacking is a common technique for testing all possible outcomes until a match is found; with classical computers this is very time consuming but with a quantum computer that can test every outcome at the same time, it would be almost instantaneous.

The majority of research around quantum computers is about building quantum security and secure communication. Once security is assured then the computers will make their way to commercial market. At present there are two major theoretical security protocols attempting to provide secure communication which allow for tampering detection and secure transmission of information.