Nine cryptocurrency companies have launched the Quantum Alliance to prepare blockchain networks for the possibility of future quantum computing attacks. However, members disagree over when the threat could become real and whether Bitcoin held in potentially vulnerable wallets should be frozen to prevent unauthorized access.

The potential exposure of Satoshi Nakamoto’s estimated 1.1 million BTC, along with millions of other coins, has intensified discussions about how the cryptocurrency industry should respond if quantum computers eventually become powerful enough to break existing cryptographic protections.

Christopher Smith, CEO of quantum-resistant layer-1 blockchain Quantus, warned that the first party to develop a cryptographically relevant quantum computer could gain access to vulnerable Bitcoin worth billions of dollars, potentially with support from a national government.

Smith told CoinDesk that whoever develops the first cryptographically relevant quantum computer (CRQC) could take control of those funds, possibly with approval from its government. He added that he hoped the first country to achieve the breakthrough would be supportive of Bitcoin.

The warning emerged on Thursday as nine crypto companies introduced the Quantum Alliance, a collaborative initiative designed to develop shared security standards and prepare Bitcoin, Ethereum and other blockchain networks for potential quantum threats.

The concern centers on whether a sufficiently advanced quantum computer could calculate a wallet’s private key using its publicly exposed public key. If successful, an attacker could gain control of the wallet and transfer its funds without permission.

The alliance estimates that approximately 6.4 million BTC, representing 30.2% of Bitcoin’s total supply, are held in addresses whose public keys have already been exposed. However, it stressed that these holdings cannot be stolen through this method using current technology because existing quantum computers lack the necessary capabilities.

Quantum Attack Timeline Remains Uncertain

The cryptocurrency industry continues to debate when quantum computers might become powerful enough to compromise Bitcoin’s security.

Bryn Bennett, chief revenue officer at The Vault, said the exact timeline is unknown, although estimates of when the technology could become dangerous have been moving closer. He argued that custodians should prioritize preparing for a potential attack rather than focusing on whether it could happen in 2028 or 2035.

According to Bennett, businesses responsible for safeguarding digital assets need to ensure they can complete the necessary security upgrades before an attack becomes feasible.

Richard Carback, chief technology officer at Postquant Labs, takes a more urgent position. He considers 2028 a realistic possibility for the arrival of a quantum machine capable of breaking current cryptographic systems.

Recent research has lowered some estimates of the computing power required to attack Bitcoin and Ethereum. Nevertheless, no existing quantum computer can currently break the cryptography securing either network. Predictions about when such technology might emerge remain disputed.

Should Bitcoin Freeze Coins Vulnerable to Quantum Attacks?

Beyond the technological challenge, the industry faces a difficult question about how to protect vulnerable holdings: should Bitcoin restrict or freeze certain coins before quantum computers become capable of stealing them?

Carback supports transferring exposed assets into more secure arrangements rather than freezing them. Bennett, however, highlighted the lack of a clearly defined authority responsible for addressing potentially vulnerable coins.

Bennett told CoinDesk that custodians are responsible for protecting their clients’ assets, not taking control of funds that appear to have been abandoned. He argued that freezing Bitcoin would be a network-level governance decision rather than a matter for individual companies.

He also warned that restricting access to vulnerable holdings could create a precedent that raises concerns about property rights and Bitcoin’s commitment to neutrality.

The debate has already attracted prominent industry figures. Binance founder Changpeng Zhao has suggested freezing Satoshi Nakamoto’s estimated 1.1 million BTC if the coins remain untouched as quantum computing advances. Bitcoin developer Jameson Lopp has also proposed restricting vulnerable holdings to prevent potential theft.

Opponents argue that freezing coins without the owner’s consent would undermine one of Bitcoin’s defining principles: that no central authority should have the power to confiscate a user’s assets.

Preparing Bitcoin for a Quantum-Resistant Future

Protecting Bitcoin against future quantum attacks would require replacing the digital signature mechanisms used to authorize transactions with cryptographic alternatives designed to withstand quantum computing. Implementing such a change would require coordination among protocol developers, miners, wallet providers, exchanges, custodians and users.

Bennett said there is no reliable estimate of the total cost involved. He argued that the greatest challenge may not be developing the cryptographic technology itself, but coordinating the transition across wallets, exchanges, custodians and protocol developers.

New signature schemes could also require more data per transaction, potentially increasing blockchain storage requirements, raising fees or reducing the number of transactions the network can process. Researchers are exploring ways to limit these effects while strengthening security against future quantum attacks.

The Quantum Alliance includes Hacken, Charles Hoskinson’s Midnight Foundation, Quantus and Postquant Labs, among other participants. The group plans to develop common security tests and issue guidance to help existing blockchain networks transition toward quantum-resistant systems.

Carback has also proposed transferring vulnerable coins into a trust arrangement that would allow legitimate owners to reclaim them by proving ownership. The idea offers a potential alternative to freezing funds, although its technical, legal and governance implications remain unresolved.

For Bitcoin, the challenge is to strengthen security against future quantum advances without compromising the principles that underpin the network. Protecting vulnerable funds will require technical upgrades and coordinated action across the ecosystem, while decisions about restricting existing coins will continue to raise difficult questions about ownership, fairness and decentralized control.