As quantum computers edge closer to breaking current cryptography, Bitcoin developers are racing to protect the world’s largest cryptocurrency from the unprecedented threat of quantum decryption.
One proposed solution, outlined in a recent Bitcoin Improvement Proposal submitted by Chilean technologist Agustin Cruz, calls for a mandatory migration to so-called Quantum-Resistant Address Migration Protocol addresses to ensure long-term protection against future attacks.
When you send Bitcoin, you use a digital signature that proves you own the coins. Right now, Bitcoin uses a cryptographic method (called ECDSA) that could eventually be broken by a powerful enough quantum computer.
The proposed protocol hides your public key until you spend the coins. That means a quantum attacker can’t attack your key until it’s briefly visible during a transaction—and by then, it’s too late: the coins have already moved.
The protocol would require users to move their Bitcoin from legacy addresses secured by ECDSA to new, quantum-resistant ones before a set deadline to protect the network from potential future quantum attacks. ECDSA stands for Elliptic Curve Digital Signature Algorithm, a cryptographic method that ensures that only the owner of the private key associated with the Bitcoin address can sign transactions.
“The main worry that pushed me to propose QRAMP was the systemic risk, the idea that a large chunk of Bitcoin’s value, especially coins sitting in older addresses where public keys might be exposed, could suddenly become vulnerable all at once,” Cruz told Decrypt. “Proposing a protocol change felt like the necessary way to tackle this network risk proactively, instead of finding ourselves scrambling in a potential future crisis.”
The proposal includes updates to the Bitcoin code, wallets, and monitoring tools, with plans to test everything on testnets, roll it out in phases, and have backup options if anything goes wrong.
As Cruz explained, the main challenge with implementing this change isn’t just technical—it’s social, noting that any proposal that risks fund loss or network splits, known as a hard fork, would naturally meet strong resistance.
“Overcoming this resistance, I believe, comes down to open dialogue and addressing concerns directly. That means clearly communicating the risks of doing nothing versus the risks of QRAMP, emphasizing that the goal is protecting the network for everyone,” Cruz said. “It also means setting a very generous timeline for migration to minimize accidental fund loss and ensuring we have robust, user-friendly migration tools built into wallets and supported by exchanges.”
Bitcoin’s quantum threat
While experts say even the most advanced classical supercomputers—such as the powerful El Capitan—would take billions of years to break Bitcoin’s encryption, they warn that future quantum computers could crack the cryptographic algorithms securing blockchain networks in mere hours.
While quantum computers may still be years away, Cruz said the case for QRAMP starts with a simple premise: Why wait for the threat to emerge before planning for it?
“My perspective is really about risk management: The impact of a successful quantum attack would be catastrophic for Bitcoin, potentially undermining its entire value proposition,” Cruz said. “Therefore, even if the probability seems low in the near term, the severity warrants proactive preparation.”
Cruz is not alone in raising the alarm about quantum threats. Similar concerns have emerged in other blockchain ecosystems. In March 2024, Ethereum co-founder Vitalik Buterin proposed a hard fork to protect Ethereum from similar quantum threats.
“I argue that actually, we are already well-positioned to make a pretty simple recovery fork to deal with such a situation,” Buterin wrote. “The blockchain would have to hard fork and users would have to download new wallet software, but few users would lose their funds.”
The plan included reversing blocks after an attack, pausing specific transactions, and introducing quantum-resistant validation.
Meanwhile, Solana developers launched the Winternitz Vault in January—an optional feature that devs claimed offered quantum resistance. The vault generates 32 private keys, hashes each 256 times to create a public key, and stores only the hash for security. After every transaction, the vault resets with entirely new keys.
While blockchain networks brace for potential attacks, some experts in quantum computing believe the technology is more likely to be used for mining than for malicious purposes.
“The goal is to start the conversation now, and ensure Bitcoin stays secure for decades,” Cruz said.
Edited by Andrew Hayward
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