30% of Bitcoin Supply Exposed to Quantum Risk, Glassnode Reports

A new analysis by Glassnode reveals that 6.04 million BTC—or 30.2% of Bitcoin's total issued supply—is exposed to potential quantum computing risks. This breakdown highlights vulnerabilities in both Bitcoin's structural design and user behavior, raising questions about long-term network security.

At its core, the issue stems from public-key exposure. Bitcoin addresses are secured by private keys, with public keys serving as verification tools. Current cryptographic assumptions make it computationally infeasible to derive private keys from public keys. However, quantum computers using Shor's algorithm could theoretically reverse this process, potentially compromising funds if public keys are already visible on-chain.

Breaking Down the 6.04M BTC Exposure

Glassnode categorizes the quantum-exposed supply into two types:

• Structural Exposure (1.92M BTC, 9.6% of supply): This arises from design choices in Bitcoin's script types, such as early pay-to-public-key (P2PK) addresses, bare multisig structures, and modern Taproot (P2TR) outputs. These outputs inherently reveal public keys, making them vulnerable by design.
• Operational Exposure (4.12M BTC, 20.6% of supply): This stems from user behavior, such as address reuse or poor wallet hygiene, which exposes public keys associated with otherwise secure script types like P2PKH or P2SH. Exchange-related balances alone account for 1.66M BTC, or 8.3% of total supply, underscoring the role of custodial practices in mitigating risk.

Notably, entity-level data shows significant variance in exposure. Major exchanges like Coinbase maintain relatively low exposure (5%), while Binance and Bitfinex are far more vulnerable, with 85% and 100% of their balances exposed, respectively. Sovereign treasuries, including those of the U.S. and El Salvador, report zero quantum exposure.

Why This Matters

The timing of this research is significant. In March 2026, Google Quantum AI estimated that fewer than 500,000 physical qubits might be enough to break Bitcoin’s elliptic curve cryptography—lower than many prior estimates. While no cryptographically relevant quantum computer (CRQC) exists yet, this timeline has injected urgency into industry discussions about mitigation strategies.

For now, quantum risk remains theoretical. Current quantum machines are noisy and far from the millions of logical qubits needed to mount a real-world attack. However, Glassnode’s analysis provides a baseline map of where vulnerabilities exist today, offering actionable insights for improving security.

Mitigation Pathways

Addressing quantum risk will require a mix of protocol upgrades and user behavior changes. Proposed solutions include adopting post-quantum signature schemes (e.g., SLH-DSA), introducing new address formats like Pay-to-Merkle-Root (P2MR), and encouraging best practices such as key rotation and avoiding address reuse. For exchanges and custodians, these steps are not hypothetical—they are practical measures that can be implemented now to reduce exposure.

Bitcoin’s conservative governance model means these changes will take years to deploy, even if consensus emerges quickly. The industry must begin planning now to ensure a smooth transition long before quantum computing becomes a tangible threat.

Market Insight

As of May 19, 2026, Bitcoin trades at $76,762, down 0.75% over the past 24 hours. While quantum risk is unlikely to impact near-term price action, the findings could influence long-term investor sentiment. Custodians and exchanges with high exposure may face scrutiny, potentially driving demand for platforms with better security practices.

For traders, the key takeaway is that quantum risk is not just a technical issue—it’s a governance challenge. Institutions and individuals alike should monitor developments in post-quantum cryptography and consider adjusting wallet management practices to minimize exposure.