The notion that quantum computing poses an imminent threat to bitcoin's security has been a topic of discussion in recent times. However, a more nuanced examination of the issue reveals that the energy requirements for such an attack are substantial, comparable to the energy output of a star. This is according to a research paper that assesses the feasibility of a quantum computer attack on the bitcoin blockchain.
The study focuses on two types of math that underpin bitcoin's security and how they are vulnerable to quantum computer attacks. The first, known as Shor's algorithm, can be used to derive a private key from a public key, thereby allowing an attacker to gain control of funds. The second, known as Grover's algorithm, can be used to speed up the trial-and-error process that miners use to find valid blocks. Nevertheless, the researchers argue that the energy requirements for running Grover's algorithm against the bitcoin blockchain are physically impossible, requiring an enormous amount of qubits and energy.
In a separate study, researchers have replicated major quantum factoring breakthroughs using a 1981 home computer and a dog, highlighting that these breakthroughs are often exaggerated and can be achieved using outdated technology. The study suggests that the current panic surrounding the quantum threat to bitcoin is misplaced and that the real vulnerability lies in bitcoin wallets, not mining. While the threat of quantum computing to bitcoin is real, it is essential to separate fact from fiction and to recognize that the development of machines capable of attacking the blockchain is constrained by the laws of physics.