Bitcoin Faces Quantum Risk: 1.7M BTC Vulnerable, Bernstein Says

Bitcoin Has Years to Fix Quantum Risk, Bernstein Says

Bitcoin isn’t under immediate siege from quantum computers, but the clock is ticking. Bernstein analysts warn that older wallets holding exposed public keys face the real danger, while newer addresses remain shielded behind hashed public keys that quantum machines can’t easily crack today.

The threat isn’t theoretical. Quantum computers could eventually run Shor’s algorithm to derive private keys from exposed public keys, opening the door to theft from wallets created before address reuse became widely discouraged. Bernstein estimates the vulnerable supply at roughly 1.7 million BTC, scattered across legacy addresses and early-era exchanges that never moved funds to safer formats.

Importantly, the firm sees no near-term risk of a chain-wide break. Quantum hardware capable of cracking 256-bit elliptic curve cryptography remains years, possibly decades, away. This buys developers time to implement post-quantum signatures before any practical attack emerges.

What This Means for Crypto

Post-quantum cryptography is the next layer of defense the network will need. Bitcoin’s protocol can be upgraded through soft forks that introduce new address types and signature schemes without forcing users to abandon their coins, but coordination among node operators and wallet providers will be essential.

For everyday holders, the message is simple: move old coins to addresses that never reuse public keys and keep them there. Exchanges and custodians will likely face pressure to migrate client funds proactively or risk losing market share to platforms that advertise quantum-safe custody.

Market Impact and Next Moves

Short-term price action should stay muted. The Bernstein report is more warning than alarm, and traders rarely price in risks that sit years ahead. Still, any headline-grabbing quantum breakthrough could spark volatility as leveraged positions react to narrative shocks.

The real opportunity lies in infrastructure. Projects already experimenting with post-quantum signatures, quantum-resistant wallets, and hybrid cryptography stand to gain mindshare if adoption accelerates. Meanwhile, miners and large holders sitting on legacy addresses represent a quiet concentration risk that could surface if migration timelines slip.

Bitcoin has time, but complacency is the bigger threat.