Quantum computing has sparked concerns about the security of Bitcoin, with claims that future machines could compromise its cryptography or overwhelm the network. However, academic research presents a more nuanced picture, highlighting the significant energy requirements and physical constraints that limit the potential of quantum attacks on Bitcoin. Two recent papers demonstrate that attacking the Bitcoin blockchain through quantum mining would demand an enormous amount of energy, equivalent to the output of a small star, while factoring breakthroughs are often based on simplified problems or rely on classical preprocessing. The real vulnerability lies in Bitcoin wallets, particularly those with exposed key information, which could be targeted by improved quantum machines in the long term.
Developers are working on fixes, including reducing key exposure and developing quantum-resistant signatures, while markets reflect a view that the threat is still largely theoretical.