Redazione RHC : 19 October 2025 08:25
The race for quantum supremacy is turning into a race for cryptocurrency survival . If quantum computers reach the promised power, they will be able to break the cryptography that underpins the digital economy, from banks to blockchain.
Technologies that once symbolized trust may now spell its end. The mathematics that ensured the security of transactions and email will prove powerless against a machine that “thinks in terms of probabilities.”
Quantum computers don’t work with 1s and 0s like classical computers: their qubits can be both at the same time. This property, called superposition, allows them to solve problems unattainable even for the most powerful supercomputers.
But the same principle could destroy the cryptography underlying the world of digital money. Quantum systems, using Shor’s algorithm, could theoretically break RSA and elliptic curves, the foundation of data security and cryptocurrency wallets. Then, private keys could be calculated from public keys, meaning any balance would no longer be secure.
“Quantum risk is not tomorrow’s threat, but today’s blind spot,” emphasizes Jai Singh Arun, co-author of “Becoming Quantum Safe.” He argues that companies that delay the transition to quantum-resistant algorithms are expanding their window of vulnerability.
Researchers are calling this moment Q-Day: the day a quantum computer will be able to crack classical cryptography for the first time . Estimates vary, but the limits are narrowing. At the TOKEN2049 conference in Singapore, Capriole Investments founder Charles Edwards claimed that Bitcoin’s security could be breached in just two to nine years.
He said that 2,330 logical qubits would be sufficient, and that most companies expect to reach that power by 2029-2030. “It seems like nothing is happening, and then suddenly… a different reality,” observed Hartmut Neven, director of Google’s Quantum AI Lab.
With the arrival of Q-Day, all data, signatures, and transactions that have not migrated to quantum-resistant algorithms will become public. It will not only be a technological event, but a historic one.
According to ECIPE , as of March 2025, China had invested approximately $15 billion in domestic quantum programs , the United States $8 billion, and Japan, the United Kingdom, and Germany rounded out the top five. In total, countries have invested over $55 billion in quantum technology development.
The danger doesn’t just lie in the future. Attackers can already intercept data encrypted today and decrypt it later, once sufficiently powerful machines become available. Therefore, the world is gradually transitioning to new post-quantum encryption standards. Cloudflare is already implementing such solutions, and the US National Institute of Standards and Technology (NIST) has approved three algorithms: ML-KEM (Kyber) for key exchange, ML-DSA (Dilithium), and SPHINCS+ for digital signatures. The agencies must complete the transition by 2033.
Some compare the quantum threat to the Y2K bug, but the similarities are deceptive. The Y2K problem had a date, a clear solution, and a global mobilization. The quantum risk is a storm without a date or boundaries: its approach is visible, but its impact is impossible to predict. Preparation is essential.
The consequences for cryptocurrencies could be devastating. Every transaction on the blockchain reveals a public key, and a quantum computer could calculate the private key from it . “When Q-Day comes, many networks will simply cease to exist,” said Mati Greenspan, founder of Quantum Economics. ” But some are already preparing and will shape the future of digital property.”
The QRL project was built from the ground up as a quantum-resistant blockchain. Its director, Michael Strike, notes that the transition to such standards is no longer a theory, but a reality: governments are demanding compatibility, companies are following suit, and the market will follow.
According to Bitbo , approximately 25 million Bitcoin addresses hold more than $100, and an arXiv report estimates that the mass migration of funds to quantum-safe wallets will take six months to a year.
Experts advise users to avoid reusing addresses and to regularly update keys. Companies should create a cryptographic map and prioritize data that must remain confidential for decades. Developers should test hybrid schemes that combine classical and post-quantum methods.
Quantum computing doesn’t have to destroy cryptocurrency: it can force it to evolve. Q-Day won’t be the end, but a reboot of digital trust. The mathematics that created cryptography will create it again, only stronger.
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