Nine cryptocurrency companies have formed the Quantum Alliance to coordinate preparations for potential quantum computing attacks on blockchain networks. However, the participants remain divided over when the technology could pose a genuine threat and whether Bitcoin held in potentially vulnerable addresses should be frozen before an attack becomes possible.
The future of Satoshi Nakamoto’s estimated 1.1 million BTC, alongside millions of other Bitcoin that could be exposed to quantum attacks, remains a major point of contention within the cryptocurrency industry.
Christopher Smith, CEO of quantum-resistant layer-1 blockchain Quantus, warned that the first party to develop a cryptographically relevant quantum computer could potentially access vulnerable Bitcoin worth billions of dollars. He suggested that such an operation might even receive backing from a national government.
Smith told CoinDesk that whoever develops the first cryptographically relevant quantum computer, known as a CRQC, could be positioned to seize the exposed funds, potentially with government approval. He added that he hoped the first government to achieve this capability would be one supportive of Bitcoin.
His warning coincided with Thursday’s launch of the Quantum Alliance, a group of nine crypto companies seeking to establish common security standards and prepare Bitcoin, Ethereum and other blockchain networks for potential quantum threats.
The underlying risk is that sufficiently advanced quantum computers could use a wallet’s publicly exposed public key to calculate its corresponding private key. If successful, an attacker could gain control of the associated funds and transfer them without the owner’s authorization.
The alliance estimates that approximately 6.4 million BTC, equivalent to 30.2% of Bitcoin’s total supply, are held in addresses with exposed public keys. It stressed, however, that the funds cannot be stolen through this method using current technology, since existing quantum computers lack the necessary computing power to break the cryptography.
Quantum Threat Timeline Remains Uncertain
A key question for Bitcoin developers and investors is how much time remains before quantum computing becomes capable of undermining the network’s security.
Bryn Bennett, chief revenue officer at The Vault, said there is no definitive timeline for when a quantum computer capable of breaking modern cryptography will become available. Nevertheless, he noted that estimates have been moving closer, making it important for custodians to prepare for a possible security transition.
Bennett argued that the priority should not be whether the threat arrives in 2028 or 2035, but whether organizations can migrate their systems before an attack becomes feasible.
Richard Carback, chief technology officer of Postquant Labs, takes a more urgent view. He said he believes 2028 is a plausible timeline for the arrival of a machine capable of breaking existing cryptographic systems.
Recent research has reduced some estimates of the computational resources necessary to attack Bitcoin and Ethereum. Despite these advances, no currently available quantum computer can break the cryptographic protections used by either network, and forecasts about when such a capability might emerge remain disputed.
Should Bitcoin Restrict Vulnerable Coins?
Beyond the technological challenge, the possibility of quantum-enabled theft raises a difficult governance question: should Bitcoin developers freeze potentially vulnerable assets before quantum computers become powerful enough to compromise them?
Carback favors transferring vulnerable coins into more secure arrangements rather than freezing them. Bennett, however, emphasized the lack of a clearly responsible authority for addressing assets that may be exposed to future attacks.
Bennett told CoinDesk that custodians are responsible for protecting their clients’ holdings, not taking control of coins considered abandoned. He argued that any decision to freeze Bitcoin would need to be addressed through the network’s governance process rather than imposed by individual businesses.
He also warned that freezing coins could introduce a different set of risks by challenging established principles of property ownership and neutrality in cryptocurrency systems.
The debate predates the alliance’s formation. Binance founder Changpeng Zhao has previously suggested freezing Satoshi Nakamoto’s estimated 1.1 million BTC if the coins remain untouched as quantum technology advances. Bitcoin developer Jameson Lopp has also proposed restricting vulnerable coins to reduce the possibility of future theft.
Opponents argue that such measures could undermine a fundamental characteristic of Bitcoin: the expectation that holders can control their assets without a central authority having the power to confiscate them.
Preparing Bitcoin for Post-Quantum Security
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 changes would require coordination among developers, miners, wallet providers, exchanges, custodians and users.
Bennett said there is no reliable figure for the overall cost of the transition. He suggested that the main difficulty would not necessarily be developing the cryptographic technology, but coordinating its adoption across the entire ecosystem, including wallets, exchanges, custodians and protocol developers.
Alternative signature systems could also increase the amount of data required for transactions. That could raise blockchain storage demands, increase transaction fees or reduce the number of transactions the network can process. Researchers are working on ways to minimize these effects while improving security against future quantum attacks.
The Quantum Alliance includes companies such as Hacken, Charles Hoskinson’s Midnight Foundation, Quantus and Postquant Labs. The group plans to develop shared security tests and publish recommendations for moving existing blockchain networks toward quantum-resistant systems.
Carback has also proposed placing vulnerable coins into a trust arrangement that would allow their rightful owners to reclaim them by demonstrating ownership. This approach could offer an alternative to freezing funds, although its implementation and legal implications remain unresolved.
For Bitcoin, the challenge is to prepare for advances in quantum computing without abandoning the principles that underpin the network. Protecting exposed funds will require technical upgrades and cooperation across the ecosystem, while decisions about restricting existing coins will continue to raise difficult questions about property rights, fairness and decentralized control.
