Quantum Bitcoin Mining

• Published in: Entropy (Basel, Switzerland) Vol. 24; no. 3; p. 323
• Main Authors: Benkoczi, Robert, Gaur, Daya, Nagy, Naya, Nagy, Marius, Hossain, Shahadat
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 24-02-2022; MDPI
• Subjects: Algorithms; Bitcoin; Blockchain; Collateral; Computers; Cryptography; Digital currencies; Digital signatures; hash functions; Monte Carlo simulation; quantum algorithms; Quantum computers; Quantum computing; Quantum entanglement; quantum security; Qubits (quantum computing); Search algorithms; hash functions; blockchain; quantum algorithms; Bitcoin; quantum security
• ISSN: 1099-4300; 1099-4300
• DOI: 10.3390/e24030323

This paper studies the effect of quantum computers on Bitcoin mining. The shift in computational paradigm towards quantum computation allows the entire search space of the golden nonce to be queried at once by exploiting quantum superpositions and entanglement. Using Grover's algorithm, a solution can be extracted in time O(2256/t), where
is the target value for the nonce. This is better using a square root over the classical search algorithm that requires O(2256/t) tries. If sufficiently large quantum computers are available for the public, mining activity in the classical sense becomes obsolete, as quantum computers always win. Without considering quantum noise, the size of the quantum computer needs to be ≈104 qubits.