Quo Vadis Qubit?

Abstract

Imagine that in a few years from now a full-scale, practical quantum computer hits the headlines. In this apocalyptic scenario, the world of cryptography would be in a state of shock, since almost everything that forms the foundations of current security would collapse. Indeed, the presence of a quantum computer would render state-of-the-art, public-key cryptography useless. All the underlying assumptions about the intractability of mathematical problems that offer confident levels of security today would no longer apply in the presence of a quantum computer. But are we really doomed? Is cryptography dead? Well, luckily no. This paper examines the technologies that will enable crypto to survive the post-apocalyptic world of quantum computing. There are many things yet to be done to offer an environment as safe as current crypto does, but the tools are there. It is now a game of engineering, pro-active standardization and ingenious mathematics, while following a careful development approach to pave a safe way through the qubits inferno.