Quantum computers need vastly fewer resources than thought to break vital encryption

Building a utility-scale quantum computer that can crack one of the most vital cryptosystems—elliptic curves—doesn’t require nearly the resources anticipated just a year or two ago, two independently written whitepapers have concluded. In one, researchers demonstrated the use of neutral atoms as reconfigurable qubits that have free access to each other. They went on to show this approach could allow a quantum computer to break 256-bit elliptic-curve cryptography (ECC) in 10 days while using 100 times less overhead than previously estimated. In a second paper, Google researchers demonstrated how to break ECC-securing blockchains for bitcoin and other cryptocurrencies in less than nine minutes while achieving a 20-fold resource reduction. Taken together, the papers are the latest sign that cryptographically relevant quantum computing (CRQC) at utility-scale is making meaningful progress. The advances are largely being driven by new quantum architectures developed by physicists and computer scientists in a push to create quantum computers that operate correctly even in the presence of errors that occur whenever qubits—the quantum analog to classical computing bits—interact with their environment. The other key drivers are ever-more efficient algorithms to supercharge Shor’s algorithm, the 1994 series of equations proving that quantum computing could break the ECC and RSA cryptosystems in polynomial time, specifically cubic time, far faster than the exponential time provided by today’s classical computers. Neither paper has been peer-reviewed.Read full article Comments