Bitcoin’s long-term security assumptions are under review as researchers assess whether quantum computing could eventually threaten early wallets, including those associated with Satoshi Nakamoto. The concern focuses on coins created under older transaction formats where public keys were exposed on-chain, potentially allowing a sufficiently advanced quantum machine to derive private keys.
On-chain analysis suggests that up to 6.89 million BTC have exposed public keys. This includes approximately 1.91 million BTC in legacy pay-to-public-key outputs and up to 4.98 million BTC revealed during prior spends. Among them are roughly 1 million BTC attributed to Satoshi, coins that have remained untouched since Bitcoin’s early years.
The theoretical risk stems from Shor’s algorithm, which could enable a large-scale quantum computer to break elliptic curve cryptography. At present, quantum hardware remains far from that capability. Firms such as IBM and Google continue to face scaling and error-correction limits, and experts widely agree that breaking Bitcoin’s encryption would require millions of stable qubits.
Developers are actively researching quantum-resistant signature schemes, including lattice-based cryptography currently under review by the U.S. National Institute of Standards and Technology. These alternatives could be introduced through a soft fork or phased upgrade, allowing users to migrate funds into new address formats before any credible threat materializes.
Roughly 3.4 million BTC have remained unmoved for more than 10 years, representing hundreds of billions of dollars at current prices. Dormant coins create a coordination challenge. If a quantum-resistant transition occurs, holders who fail to migrate funds could face exposure before updating their wallets.
This presents a core protocol dilemma. Freezing vulnerable outputs could strengthen network security, but it would conflict with Bitcoin’s foundational rule that balances cannot be altered arbitrarily.
