Bitcoin quantum exposure covers 1.92 million BTC, or 9.6% of total supply, Glassnode warned in a new report.
Summary
- Glassnode classified 1.92 million BTC as structurally exposed to a quantum breakthrough because their output types reveal public keys by design.
- Satoshi Nakamoto’s coins represent about 1.1 million BTC of the structural risk, with another 620,000 BTC in other early Satoshi-era outputs.
- A broader 4.12 million BTC, or 20.6% of supply, is operationally exposed due to address reuse and key management practices at exchanges.
Blockchain analytics firm Glassnode published a full analysis on May 20 classifying 1.92 million BTC, or 9.6% of total supply, as structurally exposed to a future quantum computing breakthrough.
The structural category covers outputs whose design reveals the public key regardless of address management. The three types at risk are Satoshi-era Pay-to-Public-Key outputs, legacy multisig structures and Pay-to-Taproot outputs.
Glassnode breaks down Bitcoin’s quantum exposure by address type
Glassnode classified 4.12 million BTC, or 20.6% of supply, as operationally exposed due to address reuse and poor key management. This is more than twice the structurally unsafe supply.
Exchange-held Bitcoin accounts for a disproportionate share. About 1.66 million BTC on exchanges, 8.3% of total supply, falls into the exposed category. Binance shows 85% exposed balances while Coinbase’s labeled balances sit at just 5% exposed.
What the structural versus operational split means for holders
Glassnode said the exposure could be reduced through better address standards and user behavior. BIP-360 proposes a quantum-resistant Pay-to-Merkle-Root output type offering a voluntary migration path for affected holders.
Crypto.news has covered the full quantum threat timeline, including the estimated 2,330 logical qubits needed to break Bitcoin’s elliptic curve cryptography.
What exchanges and custodians should do now
Glassnode advised exchanges and custodians to reduce key reuse, improve address hygiene and plan migration to quantum-proof formats before any breakthrough occurs. The firm stressed the risk is structural but not yet active.
Citi’s analysis, as crypto.news reported, found a quantum attack on major financial institutions could put $2 to $3.3 trillion of GDP at risk. The Bitcoin price page tracks how markets are pricing these long-term security concerns alongside current price action.