Glassnode’s latest analysis identifies 9.6% of Bitcoin’s total supply—1.92 million BTC—as structurally vulnerable to quantum computing breakthroughs. The vulnerability stems from public key exposure in legacy and modern output types, including Pay-to-Public-Key (P2PK), Pay-to-Multisig (P2MS), and Pay-to-Taproot (P2TR) addresses. The finding, published May 20, 2026, reignites debate over Bitcoin’s cryptographic resilience and the urgency of quantum-proof implementation standards like BIP-360.
How Bitcoin’s Elliptic Curve Cryptography Faces Quantum Risk
Bitcoin’s security relies on elliptic curve cryptography (ECC) to verify transaction signatures. Quantum computers theoretically capable of breaking ECC would require approximately 2,330 logical qubits and tens of millions to billions of quantum gates. The vulnerability is not uniform across all Bitcoin holdings. Certain output types—particularly those that expose public keys by design—create structural exposure. Satoshi Nakamoto’s estimated 1.1 million BTC (5.5% of supply) remains the largest single concentration of vulnerable coins, followed by 620,000 BTC in Satoshi-era coins (3.1%) and 200,000 BTC in Taproot addresses (1%). In contrast, 13.99 million BTC (69.8%) is structurally safe from quantum threats under current cryptographic standards.
Corporate Custodians Face 100% Exposure in Key Holdings
Glassnode’s analysis reveals stark disparities in quantum vulnerability across institutional players. Franklin Templeton, WisdomTree, and Robinhood each hold Bitcoin with 100% quantum exposure. Bitfinex similarly shows 100% exposure, while Revolut reports 99% exposure. Binance’s holdings carry 85% exposure. Grayscale, one of the largest Bitcoin trusts, faces 52% exposure across its positions. Fidelity and Coinbase show comparatively lower exposure at 2% and 5% respectively, suggesting more aggressive migration to quantum-safe address standards. These disparities highlight the fragmented state of Bitcoin infrastructure upgrades and the absence of coordinated custodian migration strategies.
BIP-360 and Post-Quantum Standards Face Implementation Bottleneck
Bitcoin developers have proposed BIP-360, which introduces Pay-to-Merkle-Root (P2MR) output types designed to be quantum-proof. ARK Invest published a white paper in March 2025 addressing quantum threat requirements, noting a critical tension: “Choosing how to implement PQC and deploy it on-chain should remain decoupled from the question of what to do about coins that remain quantum vulnerable. Yet the two matters often are conflated, the controversy around the latter often clouding discussions of the former.” This distinction matters. Wallet infrastructure improvements and address standard evolution could reduce exposure without requiring contentious protocol changes. However, no official Bitcoin developer timeline exists for BIP-360 adoption, and no affected exchanges have publicly committed to migration deadlines.
Quantum Threat Remains Theoretical but Demands Preparation
The quantum computing capability to break Bitcoin’s ECC remains speculative, with no publicly disclosed timeline for functional cryptanalytic quantum computers. Yet Glassnode’s quantification of vulnerability—1.92 million BTC across identifiable address types—creates measurable risk. The analysis separates structurally unsafe holdings (9.6%) from operationally unsafe Bitcoin (4.12 million BTC, 20.6%), though the distinction between these categories remains unclear. Bitcoin’s response to quantum threats will likely unfold through incremental wallet upgrades and address standard adoption rather than coordinated protocol intervention. The absence of custodian statements and developer roadmaps suggests the industry remains in early awareness stages.
