Quantum computers could protect our data from quantum computers

A “useless” algorithm that serves as a benchmark for demonstrating the power of quantum computers over ordinary devices could potentially be repurposed as a way to keep data secure from, ironically, quantum computers.

Quantum computers have long threatened to crack existing encryption algorithms, which rely on problems that are difficult for classical computers to solve, such as finding the prime factors of a large number. A sufficiently big quantum computer could do this, but Bill Fefferman at the University of Chicago, Illinois, and his colleagues say the devices could also…