Nine cryptocurrency firms have established the Quantum Alliance to help blockchain networks prepare for potential attacks from advanced quantum computers. However, the group faces disagreements over when such threats could become realistic and whether Bitcoin held in vulnerable addresses should be frozen to prevent possible theft.
The security of Satoshi Nakamoto’s estimated 1.1 million BTC, along with millions of other Bitcoin potentially exposed to quantum attacks, has become a growing concern for the crypto industry.
Christopher Smith, chief executive of quantum-resistant layer-1 blockchain Quantus, warned that the first organization to develop a cryptographically relevant quantum computer could potentially gain access to vulnerable Bitcoin worth billions of dollars. He suggested that a government might even support such an operation.
Smith told CoinDesk that the party developing the first cryptographically relevant quantum computer, or CRQC, could seize vulnerable funds, potentially with the approval of its national government. He expressed hope that the first government to achieve this technological milestone would be friendly toward Bitcoin.
His warning came as nine cryptocurrency companies announced the formation of the Quantum Alliance on Thursday. The initiative aims to develop consistent security standards and coordinate preparations for possible quantum attacks against Bitcoin, Ethereum and other blockchain networks.
The threat stems from the possibility that a sufficiently advanced quantum computer could use a wallet’s exposed public key to calculate its corresponding private key. Gaining access to that private key could allow an attacker to take control of the funds and transfer them without authorization.
According to the alliance’s estimates, approximately 6.4 million BTC, representing 30.2% of Bitcoin’s total supply, are held in addresses with public keys that have already been exposed. The group emphasized that this does not mean those coins can be stolen today, as existing quantum computers lack the capabilities required to break the cryptographic protections.
When Could Quantum Computers Break Bitcoin’s Security?
The timeline for a practical quantum attack remains one of the industry’s biggest unanswered questions.
Bryn Bennett, chief revenue officer at The Vault, said nobody can predict the exact date when quantum computers will become powerful enough to compromise current cryptography. However, he noted that estimates are moving closer, making advance preparation increasingly important for businesses responsible for protecting digital assets.
Bennett argued that custodians should concentrate on whether they can complete the necessary security upgrades before a quantum threat emerges, rather than focusing on whether the deadline will be 2028 or 2035.
Richard Carback, chief technology officer at Postquant Labs, offered a more immediate timeline, saying he considers 2028 a realistic possibility for the emergence of a machine capable of breaking today’s cryptographic systems.
Recent studies have lowered certain estimates of the computing resources needed to attack Bitcoin and Ethereum. Nevertheless, no existing quantum computer can currently defeat the cryptography protecting either blockchain, and experts remain divided over when such capabilities might become available.
Should Bitcoin Freeze Coins Exposed to Quantum Risks?
The possibility of future quantum attacks has sparked another controversial debate: whether Bitcoin should restrict or freeze vulnerable coins before attackers gain the ability to compromise them.
Carback favors moving potentially exposed assets into more secure arrangements instead of freezing them. Bennett, meanwhile, believes the challenge reflects a broader governance problem within the Bitcoin ecosystem.
Bennett told CoinDesk that no single organization has clear responsibility for addressing the issue. Custodians are tasked with protecting their customers’ holdings, he said, rather than claiming control over coins that appear to have been abandoned. Any decision to freeze Bitcoin would therefore need to be addressed at the network level.
He also cautioned that freezing vulnerable holdings could introduce a new problem by setting a precedent that affects property rights and Bitcoin’s commitment to neutrality.
The discussion is not new. Binance founder Changpeng Zhao has suggested that Satoshi Nakamoto’s estimated 1.1 million BTC could be frozen if the coins remain untouched as quantum computing advances. Bitcoin developer Jameson Lopp has also proposed restrictions on vulnerable coins as a way to prevent future quantum-enabled theft.
Critics argue that restricting access to Bitcoin without an owner’s consent would undermine one of the asset’s central principles: that holders should be able to control their funds without interference from a central authority.
Bitcoin’s Transition to Quantum-Resistant Cryptography
Preparing Bitcoin for future quantum threats would require replacing the digital signature systems used to authorize transactions with cryptographic alternatives designed to resist quantum attacks. Implementing the changes would involve cooperation among developers, miners, wallet providers, exchanges, custodians and individual users.
Bennett said there is no credible estimate of the transition’s overall cost. He argued that the main obstacle may not be creating the required cryptography, but coordinating its implementation across the network’s many services and infrastructure providers.
New signature schemes could also increase the amount of data required for each transaction. This could place greater demands on blockchain storage, raise transaction fees or reduce Bitcoin’s transaction capacity. Researchers are exploring methods to limit these trade-offs while strengthening security.
The Quantum Alliance includes Hacken, Charles Hoskinson’s Midnight Foundation, Quantus and Postquant Labs, among other companies. Its plans include developing shared security tests and publishing guidance to help blockchain networks adopt quantum-resistant systems.
Carback has proposed another possible approach: placing vulnerable coins in a trust structure that would allow legitimate owners to recover their holdings by proving ownership. This could offer an alternative to freezing funds, although the proposal’s practical and governance implications remain unresolved.
For Bitcoin, the challenge is to prepare for advances in quantum computing without undermining the principles that underpin the network. Protecting potentially exposed funds will require technical improvements and industry-wide coordination, while decisions about restricting existing coins will continue to raise difficult questions about ownership, fairness and decentralized control.
