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Stochastic magnetic circuits rival quantum computing
Circuits based on the stochastic evolution of nanoscale magnets have been used to split large numbers into prime-number factors — a problem that only quantum computers were previously expected to solve efficiently.
Data encryption typically relies on the practical difficulty of a process called prime factorization. In this process, a huge number (represented by 1,024 or more bits) is decomposed into a product of prime numbers. Such a task is notoriously time-consuming for conventional computers and is estimated1 to be much more efficient for a future quantum computer — assuming that such a machine is built and uses a method called Shor’s algorithm2. Writing in Nature, Borders et al.3 demonstrate that an integrated circuit (a computer chip) containing nanoscale magnets can split numbers up to 945 into prime factors efficiently. Such a nanomagnet chip is much easier to make than a quantum computer and, if improved, could threaten data encryption.