Quantum Bitcoin Mining Requires Astronomical Resources, Study Finds

Pierre-Luc Dallaire-Demers and colleagues at BTQ Technologies present the first end-to-end cost analysis of fault-tolerant hardware required to use Grover’s algorithm for Bitcoin mining. The open source estimator considers all aspects of a quantum attack, from reversible oracles to energy consumption on a scale comparable to national power grids. The study reveals that while a modest quantum advantage can be achieved under certain circumstances, scaling to Bitcoin’s current security levels requires astronomical qubit counts, potentially reaching 10^23, and energy consumption approaching the Kardashev Type II civilization threshold. This effectively demonstrates the impracticality of quantum mining with predictable technology.

Quantum resource thresholds hinder the viability of Bitcoin mining in the short term

Qubit requirements to mine Bitcoin by January 2025 difficulty will reach around 10²³. This figure exceeds the number of atoms in a large building and represents a previously unappreciated threshold for quantum mining feasibility. Such enormous scale dwarfs earlier estimates dependent on theoretical speedups, revealing the practical limitations of using Grover’s algorithm for Bitcoin mining due to the large amount of fault-tolerant hardware required. Achieving even a modest quantum advantage requires energy consumption approaching 10²⁵ watts, approaching the Kardashev Type II threshold—comparable to the total energy output of a star—which effectively puts quantum mining beyond the realm of foreseeable technology.

A superconducting surface code fleet attempting to mine Bitcoin at January 2025 difficulty levels would require about 10 8 physical qubits and consume about 10 4 megawatts of power. At the projected January 2025 main grid level, the kwbit requirement rises to about 10 23, with energy consumption reaching about 10 25 watts, approaching a Kardashev Type II civilization scale. This considerable demand escalates dramatically with increasing difficulty. Such a power draw is comparable to the entire output of a large nation, highlighting the immense scale of resources required. The analysis also considered the energy costs of reversible oracles for the double-SHA-256 mining process, along with the logistical demands of operating a large quantum computer fleet; even optimistic estimates of power efficiency per kwbit do not change the overall conclusion.

Grover’s Algorithm Hardware Requirements and Surface Code Error Correction for Bitcoin Mining

The analysis hinged on a detailed, open-source estimator designed to map the theoretical speedup of Grover’s algorithm into concrete hardware requirements. Grover’s algorithm is a faster but still computationally intensive way to search a database, similar to using a more efficient librarian to find a specific book. This estimator carefully accounted for every component of a potential quantum attack, starting with the creation of ‘reversible oracles’, specialized quantum circuits needed to perform the cryptographic hashing at the heart of Bitcoin mining. The team then modeled ‘surface code’ error correction, a grid of qubits that act like a team of proofreaders, each checking its neighbors for errors to ensure accurate calculations, an essential step for building a stable quantum computer.

Bitcoin’s quantum vulnerability assessment excludes protocol adaptation costs

This analysis decisively demonstrates the impracticality of quantum mining with foreseeable technology, which deliberately limits its scope to hardware costs. The authors acknowledge that their analysis does not address potential defensive measures within the Bitcoin protocol itself, such as changes to signature schemes or hashing algorithms designed to increase quantum resistance. This omission highlights a critical tension; focusing solely on the attacker’s resources neglects the possibility of Bitcoin adapting to mitigate the quantum threat, a changing interaction not fully captured by static cost determinations.

Recognizing the potential for Bitcoin to develop defense mechanisms is important, but this analysis provides a strong baseline understanding of the sheer scale of resources required for a quantum attack on its mining process. It establishes that even with optimistic assumptions about hardware development, a successful attack would require a quantum computer that exceeds the capacity of any existing or realistically foreseeable infrastructure. The analysis definitively establishes that using quantum computing to mine Bitcoin is not practically viable with current or foreseeable technology. By detailing the hardware and energy requirements, it moves beyond theoretical speedups to quantify the enormous scale required for a quantum attack on the Bitcoin network. It explains that the primary quantum threat to Bitcoin remains attacks on the cryptographic signatures, rather than the ability to generate new blocks through mining.

The research showed that quantum mining of Bitcoin is virtually impossible with current or near-future technology. Calculations have revealed that a quantum computer that can mine even at a moderate level requires about 10 8 physical qubits and 10 4 megawatts of power, which quickly scales to 10 23 qubits and 10 25 watts at the current Bitcoin network difficulty. This analysis focused solely on the hardware cost of a quantum attack, recognizing that Bitcoin could potentially adapt its protocols to increase quantum resistance. As a result, the primary quantum vulnerability remains attacks on the cryptographic signatures used to secure transactions, rather than the mining process itself.