• echo64@lemmy.world
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      1 year ago

      It takes about a billion qbits to break 2048bit encryption, so a while. I saw something about reducing it to about 20 million qbits recently, but it’s still a while off.

      • Overzeetop@sopuli.xyz
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        1 year ago

        More importantly, how long until I can guarantee a 51% chance of solving every bitcoin block?

        • cyd@lemmy.world
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          1 year ago

          Hash functions are not known to be quantum vulnerable (i.e., there’s no known quantum algorithm that provides an exponential speedup, best you can do is to use Grover’s algorithm to slightly speed up the brute force search). So maybe never.

      • frezik@midwest.social
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        1 year ago

        IIRC, those several million qubit computers out there right now aren’t really comparable, either. They’re using a ton of qubits, expecting a lot of them to fall out of superposition, but hoping they have enough to get a useful result. IBM’s approach is to try to get the most out of every qubit. Either approach is valid, but IBM’s 1000 qubits can’t be directly compared to millions of qubits used elsewhere.