Samson Mow Warns Rushed Bitcoin Quantum Fix Could Create Security Risks

Bitcoin transactions use elliptic-curve digital signatures to protect assets. Once an address reveals its public key, a sufficiently powerful quantum computer could eventually derive the private key and steal the funds. The threat is not exploitable today, but the permanent public record of blockchain data means exchanges and long-term holders must plan ahead to migrate to quantum-secure addresses.

Coinbase’s independent advisory board on quantum computing and blockchain released a report on June 11, 2026, estimating that the public keys for about 7 million BTC have been exposed. About 1.7 million BTC are held in early P2PK addresses, while roughly 5 million BTC are exposed through address reuse and largely consist of active funds such as exchange cold wallets. Attackers can collect the data now and attempt to crack it later.

Bitcoin uses elliptic-curve cryptography to protect assets and communications, but sufficiently powerful quantum computers could eventually break its current encryption. Experts say the more immediate danger is a “harvest now, decrypt later” strategy, in which attackers intercept and store large volumes of encrypted communications today, then recover sensitive historical data once the technology matures. The threat extends beyond wallet private keys.

Security experts and an early-stage venture investor have recently warned that historical communications and infrastructure data across the Bitcoin ecosystem may already be targets for quantum attacks. Ethereum has begun work on a post-quantum migration, but as of this report, neither Bitcoin nor related companies had publicly committed to specific safeguards, disclosed investment amounts or set completion dates. The upgrade timetable and division of responsibility therefore remain unclear.

Bitcoin, with a market capitalization of about $1.3 trillion, relies on elliptic-curve cryptography to secure transactions. If large-scale quantum computers become viable, exposed public keys could potentially be used to derive private keys. Bitcoin developers have therefore proposed BIP-360, adding a quantum-resistant migration to the network’s long-term technical roadmap to reduce the potential risk to existing assets.

Proposed in 2025, BIP-360 introduces Pay-to-Merkle-Root (P2MR), which removes Taproot’s public-key spending path and instead locks scripts with a Merkle root, allowing keys to remain hidden until funds are spent. The proposal remains a draft, with no mainnet activation date, and does not yet introduce a complete post-quantum signature scheme. It nevertheless establishes a foundation for future upgrades.

Bitcoin currently relies on ECDSA and Schnorr signatures to secure asset ownership. A sufficiently powerful quantum computer could eventually use Shor’s algorithm to derive private keys from exposed public keys. Although the threat remains confined to laboratory experiments, migrating the network’s wallets, software and users would take considerable time, making early development of quantum-resistant safeguards critical to asset security.

Speaking at Paris Blockchain Week on April 16, 2026, Blockstream CEO Adam Back advocated introducing an optional upgrade first and giving users 10 years to move funds to quantum-resistant addresses. He estimated that a real threat remains at least 20 years away. Blockstream’s research division proposed a hash-based signature scheme in December 2025. The migration could also clarify whether the roughly 500,000 to 1 million Bitcoin attributed to Satoshi Nakamoto can still be moved.

Bitcoin transactions rely on elliptic-curve digital signatures. A sufficiently powerful quantum computer running Shor’s algorithm could derive private keys from exposed public keys and steal assets. Replacing the signature mechanism would require network-wide consensus and asset migration, drawing attention to StarkWare’s upgrade-free approach as a fallback until longer-term changes such as BIP-360 are completed.

On April 9, 2026, StarkWare Chief Product Officer and BIP-360 co-author Avihu Levy published the QSB paper and open-source code. The system uses Bitcoin’s existing Script constraints and hash-based proofs to create quantum-resistant transactions without a soft fork or miner activation. Each transaction requires substantial offline GPU computation at an estimated cost of $75–$200, and the tool is currently intended for emergency recovery.

Quantum computers could threaten Bitcoin private keys and onchain assets if they become capable of breaking today’s elliptic-curve cryptography. BOLT Technologies founder Yoon Auh said adopting post-quantum cryptography would require more than a protocol overhaul. Large numbers of wallets, exchanges and holders worldwide would also need to migrate in coordination, testing the efficiency of decentralized governance.

The latest report focuses on whether Bitcoin governance can move quickly enough to address quantum risks, comparing the upgrade capacity of decentralized networks such as Ethereum with that of centralized systems. It gives no value for the assets at risk, potential date of a quantum attack or upgrade timetable. However, it stresses that assets held at legacy addresses could remain exposed if some wallets fail to migrate, even after the core protocol is updated.