A distant threat. The security of the Bitcoin network is the subject ofin-depth academic analyzes at the start of 2026particularly in the face of hypotheses of attacks by quantum calculation. While some observers fear rapid obsolescence of current cryptography, recent research tempers these predictions. Studies published by experts from BTQ Technologies and the University of Auckland demonstrate that physical and energy barriers still protect the protocol against theoretical threats. If two major algorithms, those of Shor and Grover, present distinct risks for wallets and mining, their concrete implementation faces material constraints beyond contemporary technological capabilities.
The key points of this article:The security of the Bitcoin network has been the subject of academic analysis in the face of potential threats from quantum calculations in 2026.
Hardware and energy constraints have protected the Bitcoin protocol against quantum theoretical attacks, with energy consumption comparable to that of a small star needed for a 51% attack.
Bitcoin: The energy limits of quantum mining
Applying Grover's algorithm to the mining process constitutes theone of the central concerns for the integrity of the consensus. In theory, this technique makes it possible to speed up the trial and error search necessary for validating blocks. However, a study conducted by Pierre-Luc Dallaire-Demers and published in March 2026 concludes that the theoretical advantage evaporates when material and energy requirements are taken into account. To carry out a 51% attack against theBitcoin SHA-256 algorithman attacker would thus have to mobilize a quantum infrastructure capable of managing approximately 10²³ qubits with an estimated consumption of 10²⁵ watts. This figure is comparable to the energy production of a small staror about 3% of the power of the Sun! To put this data into perspective, the Bitcoin network current only consumes around 15 gigawatts. Thus, the power required for such an offensive exceeds by several orders of magnitude accessible energy resources to an earthly civilization. As a result, the probability that one actor can dominate block production by quantum means remains zero in the current state of applied physics. On this subject, watch a video from our teams which takes stock of the latest advances in the quantum sector. The risk the most tangible concerns Shor's algorithmwhich targets the security of private keys. A sufficiently powerful quantum machine could derive a private key from a public key exposed on the blockchain. This scenario particularly threatens old addresses or those whose key information is already visible.
Relative portfolio vulnerability and industry responses
Although recent research from Google suggests that such an attack could run in minutesthe authors specify that the construction of a stable machine, capable of coordinating tens of thousands of atoms without loss of information, remains today physically impossible. Faced with these challenges, the technical community is already anticipating the necessary developments. Markets and developers are paying close attention to updates such as BIP-360, aimed at reducing portfolio exposure. Current forecasts estimate the probability of integration of signatures resistant to quantum computing by 2027. Furthermore, researchers criticize the validity of certain “quantum breakthroughs” announced in the past. A parody but rigorous study conducted by Peter Gutmann shows that many claimed exploits rely on excessive simplifications or on preprocessing by classical computers, not reflecting the real strength of modern encryption systems like RSA-2048. The quantum threat to Bitcoin, although scientifically founded in the long term, remains limited by engineering and fundamental physics imperatives. The distinction between the theoretical capabilities of algorithms and the resources necessary for their massive execution helps stabilize investor expectations. While mining protocols seem protected by their excessive energy, the industry focuses its research efforts on securing cryptographic signatures. The resilience of the network will depend on its ability to integrate these new security standards before quantum computing power becomes accessible on an industrial scale.