Headlines frequently suggest that quantum computing might soon undermine bitcoin, with claims about future machines cracking its cryptography or overwhelming the network in minutes. However, academic research provides a more realistic perspective. Some cited ‘breakthroughs’ are based on simplified problems not representative of actual cryptography. According to Bitcoin hardware entrepreneur Rodolfo Novak’s shared research papers on X, attacking Bitcoin with quantum computers would require energy equivalent to a small star.
Bitcoin security relies on two types of math, each threatened differently by quantum computing. Shor’s algorithm could theoretically derive private keys from public ones, allowing fund theft and compromising ownership guarantees. Grover’s algorithm targets mining by speeding up the trial-and-error block search, but as research shows, its advantages diminish when considering real-world machine construction.
Two recent papers—one an engineering analysis, the other a satire—highlight these issues. They suggest that current crypto Twitter panic mixes genuine concerns with sensational news cycles. The first paper by Pierre-Luc Dallaire-Demers and BTQ Technologies, published in March 2026, examines if quantum computers could out-mine BTC using Grover’s algorithm, which accelerates miners’ trial-and-error processes for finding valid blocks.
Mining protects BTC from a 51% attack, where an entity controls enough hash power to alter transaction history or censor the network. Quantum mining dominance would threaten consensus itself. However, researchers argue that hardware and energy costs make this impractical. Running Grover against SHA-256, bitcoin’s math formula for block addition, is physically impossible with current quantum capabilities.
Quantum hardware required would be unprecedented, involving hundreds of thousands of operations per search step, each needing thousands of qubits to manage errors. Bitcoin’s ten-minute block production window demands massive parallel machine operation. At January 2025 difficulty, estimates suggest a quantum mining fleet would need about 10^23 qubits and 10^25 watts, close to a star’s energy output—far exceeding the blockchain’s 15 gigawatts.
A quantum 51% attack is not just costly; it’s physically unreachable for any civilization at current power levels. The second paper by Peter Gutmann of Auckland University and Stephan Neuhaus of Zürcher Hochschule critiques recent headlines claiming imminent encryption breaches by quantum computers. They replicate major quantum factoring ‘breakthroughs’ using a 1981 VIC-20 home computer, an abacus, and a dog named Scribble.
The joke underscores the seriousness: factoring, crucial for modern encryption, involves finding prime numbers that multiply to form a large number. Shor’s algorithm threatens bitcoin wallets by potentially enabling quantum machines to factor these numbers. However, Gutmann and Neuhaus show most demonstrations have been misleading, using numbers with close prime factors or preprocessing steps on regular computers.
Their focus is on a paper claiming progress in breaking RSA-2048 encryption using a D-Wave machine. They found the example numbers easily factored using an emulator within seconds, as they were chosen for ease of solution via a 1945 algorithm adapted by John von Neumann. The authors suggest that the pressure to publish impressive-sounding results in quantum factoring leads to rigged demonstrations.
They propose new standards requiring random numbers and no preprocessing to genuinely assess progress. While not dismissing quantum threats, these papers highlight bitcoin wallets as more vulnerable than mining due to exposed key information on older blockchain addresses.
Recent research from Google researchers suggests that the power needed for such attacks might decrease significantly, potentially threatening Bitcoin’s encryption in minutes. However, building such machines remains physically impossible without significant technological advances. Some recent studies have withheld technical details, and experts warn about potential non-disclosure of progress.
Developers are already addressing these risks by reducing key exposure and designing quantum-resistant signatures. Market sentiment suggests the threat is still theoretical, with low chances of Bitcoin changing its mining algorithm before 2027 but higher probabilities for wallet risk reduction upgrades like BIP-360.
While the quantum threat to Bitcoin is real, constructing machines capable of such attacks faces physical constraints, emphasizing the need for ongoing vigilance and innovation.