Bitcoin can't wait 20 years; the quantum threat is already looming.

Author: Youssef El Maddarsi Source: cointelegraph Translation: Shan Ouba, Jinse Finance

Bitcoin's 20-year quantum security window has collapsed. 25% of the Bitcoin supply is stored in high-risk addresses and urgently needs to be migrated.

Some Bitcoin supporters believe that the network will not face a substantial quantum threat in the near future—they cite the post-quantum standard approved by the National Institute of Standards and Technology (NIST), claiming that Bitcoin can be upgraded before the advent of quantum computers capable of breaking cryptography. This confidence is based on a high-risk assumption: the quantum threat will only truly arrive when quantum computers can crack keys in real time. Adam Back once suggested that Bitcoin had at least 20 to 40 years to prepare, but in fact, the quantum threat already exists.

Bitcoin cannot rely on a long upgrade path of decades.

Some readers may strongly object, insisting that the timeline for quantum technology development remains highly uncertain, and there's no need to rush into action; excessive warnings could even trigger unnecessary panic. However, the facts do not warrant our complacency. IBM recently achieved a major breakthrough in practical quantum computing. Its next-generation chips and faster error correction technology are expected to enable the company to achieve quantum supremacy by 2026 and launch an early fault-tolerant quantum system by 2029. This quantum technology race is intensifying. At the 2025 Devconnect conference, Vitalik Buterin stated that quantum computers may break elliptic curve cryptography sooner than expected, possibly even before the 2028 US presidential election, and advocated that Ethereum should transition to quantum-resistant cryptography within a few years. This contrasts sharply with the "security narrative" promoted by some Bitcoin enthusiasts, indicating that even the founder of Ethereum believes the window of opportunity for quantum threats is far more pressing than people imagine. I. Quantum Risks Already Have Market Impact A recent Deloitte report shows that approximately 4 million Bitcoins (25% of the total available supply) are stored in addresses whose public keys are vulnerable to quantum attacks. Researchers have long warned that sufficiently advanced quantum computers can use the Scholl algorithm to deduce private keys from public keys, allowing attackers to instantly empty traditional wallets. This is not a problem unique to Bitcoin. Ethereum and most current blockchains rely on elliptic curve cryptography, a foundation that quantum technology will fundamentally disrupt. Vitalik Buterin has developed contingency plans for scenarios where quantum computers could crack Ethereum accounts.

Second, the argument of "upgrading later" is not valid in reality

The core of the view that "Bitcoin has decades to prepare for quantum threats" is the belief that NIST's post-quantum cryptography (PQC) standard can be directly adopted before a substantial attack occurs. However, upgrading Bitcoin is not a simple patch fix, but a fundamental reconstruction of the protocol signature mechanism. Researchers at the University of Kent pointed out that upgrading Bitcoin to a quantum-resistant cryptographic system could require up to 75 days of downtime; if the network needs to reduce its computing power during the migration to reduce the attack surface, the downtime could even exceed 300 days. For an asset class worth trillions of dollars, a long-term global downtime is far from an acceptable "timely fix" solution for the industry.

Even if Bitcoin can achieve a smooth migration at the technical level, political realities will pose another obstacle. Bitcoin's governance culture has always resisted change, as evidenced by the fact that even the relatively mild Taproot upgrade underwent several years of debate and coordination.

The high-risk operation of forcibly migrating the entire network to a completely new encryption foundation will inevitably trigger ideological conflicts, potential chain forks, and long-term uncertainty. The idea that such a radical reconstruction can be easily implemented decades later ignores the adversarial game that Bitcoin faces in simpler upgrades. Meanwhile, the development of quantum technology is far exceeding most people's expectations. The European Commission and member states recently released a coordinated roadmap to transition the EU's digital infrastructure to post-quantum encryption, addressing the threat posed by quantum computers to existing encryption systems. The plan sets a unified timetable: all member states must launch national post-quantum encryption strategies and initial migration work by 2026; critical infrastructure and other high-risk areas must adopt quantum-resistant encryption by 2030; and by 2035, the post-quantum encryption transition of all upgradable systems must be completed. III. The Market Impact of Delayed Transition Could Be Catastrophic For the encryption industry, the urgency of this threat is also reflected in the potential market shock caused by an improper transition. If attackers use quantum hardware to crack private keys from dormant Bitcoin wallets, they could suddenly transfer millions of long-dormant Bitcoins, dumping them on exchanges and causing a price crash. Similarly, if malicious quantum miners can continuously solve Bitcoin's proof-of-work problem, it will undermine the decentralized nature of mining, turning this global industry into an oligopoly dominated by quantum technology holders. These risks will completely reshape the market landscape before the so-called "20-40 year security window" arrives. Post-quantum cryptography is inevitable, but it must be deployed before attackers acquire the necessary hardware, not as a post-hoc remedy. The NIST standard provides a roadmap, but not absolute guarantees. The transition will be lengthy, controversial, and disruptive. Attempting to postpone it for decades could expose Bitcoin and the entire crypto ecosystem to the most severe security challenges of this century. For the past 15 years, the crypto industry has been defending decentralization, trustlessness, and user sovereignty. Now, quantum computing presents a new challenge: will the industry act proactively, or wait for a crisis to erupt before reacting passively? The cost of misjudging far outweighs the cost of prior preparation. Many might believe Bitcoin still has decades of buffer time, but evidence points to a completely different conclusion: the clock of the quantum threat is already ticking, and the market is quietly adjusting. The only question is whether the industry can act before time runs out.