Idea in Brief
The Promise
Quantum computers can solve problems exponentially faster than classical computers can. They will bring about two huge changes: an end to our current infrastructure for cybersecurity over public networks and an explosion of algorithmic power that holds the promise to reshape our world.
The Challenges
Scientists face myriad challenges in developing commercially relevant quantum computers. But once they are overcome, the disruption caused by postquantum cryptography will eclipse that of Y2K, which cost the United States and its businesses more than $100 billion to mitigate.
The Impact
This article examines the way quantum computers will not only upend digital security but spur investment, reshape industries, and spark innovation.
In 1994, mathematician Peter Shor introduced a quantum-computing algorithm that could reduce the time it takes to find the prime factors of large numbers from billions of years using a conventional transistor-based computer to a few days using a quantum computer. This was an enormous breakthrough, because prime factorization is the foundation for much of our present encryption and information security infrastructure. Seven years later, IBM scientists successfully demonstrated the algorithm on a quantum machine—albeit a very small one—for the first time, proving that quantum computers could be built and that Shor’s algorithm could be implemented.