The notion that quantum computers could crack bitcoin's cryptography and overwhelm the network has sparked concern, but recent studies indicate that the threat may be overstated. Two papers highlight the limitations of quantum attacks on bitcoin, with one finding that a quantum mining attack would require the energy output of a star, while another demonstrates that quantum factoring breakthroughs can be replicated using a 1981 home computer. The research suggests that the energy required for a quantum attack on bitcoin's mining process is equivalent to that of a small star, making it physically unfeasible. Furthermore, many quantum factoring breakthroughs have been exaggerated, with some researchers using simplified problems or cheating by picking numbers with easily guessable prime factors.
While the quantum threat to bitcoin is real, it is primarily focused on wallet security rather than mining. Developers are already working on fixes, including ways to reduce key exposure and new types of signatures designed to withstand quantum attacks.