Remapping the quantum frontier

In 1994 the mathematician Peter Shor, then working at AT&T Bell Laboratories in the US, applied quantum mechanics to an age-old problem in number theory and made a remarkable discovery. He showed that a computer that operates on and processes quantum systems could factor large integers exponentially faster than a conventional computer. This result attracted a lot of attention because the difficulty of factoring large numbers is what ensures the security of modern cryptography schemes – even the best conventional computer would take several thousand years to factor a number with more than about 150 digits. Shor's quantum factoring algorithm could, in principle, break such encryption standards – a possibility that led to an explosion of interest in quantum information science. Until then it was a field that had largely been a mere curiosity, despite notable contributions from the likes of Richard Feynman and David Deutsch.