The prospect of quantum computers threatening the security of bitcoin has been a topic of concern in recent years. However, according to recent studies, the energy required to launch a quantum attack on the bitcoin blockchain is equivalent to that of a small star.
This is due to the enormous amount of energy needed to power the quantum hardware required to run the complex mathematical calculations involved in bitcoin mining. In fact, researchers estimate that a quantum mining fleet would need roughly 10²³ qubits drawing 10²⁵ watts, which is comparable to the energy output of a star. Furthermore, another study has found that many of the reported quantum factoring breakthroughs are overstated, with some researchers using simplified problems or cheating by using preprocessed data.
The real vulnerability to quantum attacks lies in bitcoin wallets, particularly those with exposed key information on the blockchain. While the threat is still a concern, developers are working on solutions to mitigate the risk, including reducing key exposure and implementing new signature types resistant to quantum attacks.