What happens when a quantum computer becomes powerful enough to break Bitcoin technology?
This question became a reality in December 2024, when Google unveiled Willow, a quantum chip it said could finish in minutes a calculation that would take the fastest supercomputers an almost unimaginable span of time. Microsoft followed with a quantum chip of its own.
By May 2025, BlackRock, the world's largest asset manager, had added quantum computing to the official risk factors in the regulatory filing for its Bitcoin ETF.
For context, Project Eleven, a firm dedicated to Bitcoin's quantum risk, estimates that roughly 6.9 million BTC, about a third of all the Bitcoin in existence, sits in addresses that would be exposed to a sufficiently powerful quantum attacker, most of it through the reuse of wallet addresses.
The firm has pegged "Q-Day," the moment such an attack becomes possible, as arriving as early as 2030, with a baseline scenario around 2033, and warned this year that Bitcoin may already be running short of time to move its defenses into place.
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On July 23, a Wall Street group announced the formation of the Bitcoin Security Consortium, an initiative dedicated to the long-term security and resilience of the Bitcoin network, backed by an aggregate $15 million in member pledges over the next three years.
The founding members are a cross-section of the institutional Bitcoin economy: BlackRock, Coinbase, Fidelity Digital Assets, Strategy, Cathie Wood's ARK Invest, Jack Dorsey's Block, Galaxy, Adam Back's Blockstream, and Anchorage Digital, spanning the holders, custodians, exchanges, infrastructure firms and asset managers now anchored to Bitcoin.
The money will fund the developers and researchers already working on Bitcoin's security, including the long-term task of preparing the network for a potential era of quantum computing.
Each member directs its own funding independently to the developers and organizations it chooses.
"As long-term holders, we have every incentive to see Bitcoin remain secure for generations. Funding the people who do this work, and helping inform the conversation around it, is a natural way for us to contribute," said Phong Le, chief executive of Strategy, the largest corporate holder of Bitcoin.
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