Satoshi-era bitcoin faces a bigger quantum threat after Google’s new Willow breakthrough Google says its Willow chip can prepare the special quantum states needed for advanced calculations with about 40 times fewer errors, reducing one of the hardware bottlenecks behind any…
ture attempt to crack bitcoin wallets. – Google said its Willow quantum chip reduced errors about 40-fold when preparing “magic states,” a resource needed for quantum calculations that could eventually threaten Bitcoin wallets. – The experiment achieved about 99.99 percent fidelity among states that passed inspection, though only about 8 percent of preparation attempts succeeded and substantial scaling challenges remain. – The findings do not make a Bitcoin attack 40 times cheaper, but they advance an engineering method that could help future quantum computers sustain the roughly 500,000 reliable magic states per second required under one modeled attack. Google says its Willow quantum chip has cut errors about 40-fold when preparing special states used in quantum calculations, tackling a costly step toward building machines powerful enough to crack bitcoin wallets
The result, published in Science this week, deals with something that rarely comes up in the bitcoin quantum debate — which usually focuses on how big a machine an attacker would need while underplaying how much of that machine would be occupied getting ready to calculate. Why the oldest coins give an attacker more time A bitcoin wallet uses a secret key to approve payments and a matching public key that lets the network check those approvals. Spending typically reveals the public key, while some payment types expose it from the start.
Working backward from it to the secret is supposed to take an impractical amount of computing, which makes it practically impossible to reverse-engineer crypto wallets. However, a large enough quantum computer running Shor’s algorithm could, in theory, do that math. Whoever recovered the secret key…