Overview:

• Glassnode reports that 7.12 million BTC, representing 35.4% of the issued Bitcoin supply, sits behind publicly exposed keys, highlighting potential long-term quantum computing risks.

• Address reuse accounts for 25.8% of supply exposure, including 11.6% held on exchanges. However, these holdings are not currently compromised by quantum attacks.

• Bitcoin's draft BIP 360 proposal aims to reduce prolonged public-key exposure through a new output structure, but further development and network adoption are required.

Bitcoin’s long-term security debate has intensified after Glassnode reported that 7.12 million BTC, representing 35.4% of the issued supply, sits behind public keys already visible on-chain. The November 10 findings quantify potential exposure to future quantum attacks, not cryptocurrency stolen or vulnerable to existing computers.

What Glassnode’s Figures Reveal

Glassnode reported that 25.8% of Bitcoin supply faces exposure associated with address reuse, including 11.6% held on exchanges. The exchange portion is included within the reuse figure and should not be counted separately.

In May, Glassnode estimated visible-key exposure at 6.04 million BTC, equivalent to 30.2% of supply. November’s 35.4% reading represents an increase of 5.2 percentage points, reflecting measured exposure rather than proven advances in quantum computing.

“Moving those coins to a fresh address ends this exposure,” Glassnode said about reuse-related vulnerability. However, moving funds does not guarantee protection against every possible future attack.

Why Public Keys Create Potential Risks

Bitcoin transactions rely on private keys for authorization and corresponding public keys for signature verification. Revealing a public key does not allow conventional computers to recover the private key practically.

A sufficiently powerful quantum computer could theoretically use Shor’s algorithm to reverse the underlying mathematical relationship. No demonstrated machine currently threatens Bitcoin’s cryptography at that scale.

Some Bitcoin output formats expose public keys by design. Others reveal them when coins are spent. Reusing previously revealed keys can leave remaining balances exposed indefinitely, creating what Glassnode describes as exposure at rest.

Wallet Security and Exchange Implications

For individual holders, avoiding address reuse and transferring funds to fresh, appropriate addresses can reduce certain exposure risks. Hardware wallets and recovery-phrase protection remain important against conventional theft, but cannot independently eliminate future quantum threats.

Exchanges and institutional custodians face additional responsibilities. They can review address histories, identify exposed holdings and prepare migration strategies without implying that their systems have been breached.

What BIP 360 Proposes

Draft Bitcoin Improvement Proposal 360 introduces Pay-to-Merkle-Root outputs to reduce prolonged public-key exposure while preserving script-tree functionality. However, BIP 360 is not an activated Bitcoin upgrade. Its approach primarily addresses long-duration exposure, while attacks during transaction confirmation may require post-quantum signature mechanisms.

Implementation would involve technical review, network coordination, wallet compatibility and participation from holders, including those controlling dormant coins. Developers must also weigh larger signatures, transaction fees and network performance when assessing quantum-resistant alternatives, as new security improvements can introduce significant operational trade-offs.

What Comes Next

Glassnode’s data provides a measurable starting point for security planning. Progress on cryptographic research, Bitcoin proposals and independently demonstrated quantum capabilities will determine how urgently wallets must adapt. For now, visible public keys represent a potential future vulnerability, not evidence of an ongoing attack.

Also Read: Could Tesla and SpaceX's Bitcoin Strategy Change the Future of Corporate Crypto Adoption?

FAQs:

1. What is Bitcoin public key exposure?

Bitcoin public key exposure occurs when a wallet's public key becomes visible on the blockchain through its address format or transaction history. Although public keys are safe against known practical attacks today, they could become vulnerable to sufficiently advanced quantum computers.

2. How much Bitcoin is exposed to potential quantum computing risks?

According to Glassnode's November 10 findings, approximately 7.12 million BTC, representing 35.4% of issued supply, sits behind publicly visible keys. This figure increased from 6.04 million BTC, or 30.2%, reported in May 2026.

3. Can quantum computers steal Bitcoin from exposed wallets?

A sufficiently powerful quantum computer could theoretically derive private keys from exposed Bitcoin public keys using Shor's algorithm. However, no publicly demonstrated quantum computer currently possesses the capabilities required to execute such attacks against Bitcoin.

4. How can Bitcoin holders reduce public key exposure risks?

Bitcoin holders can reduce certain risks by avoiding address reuse and transferring funds to fresh addresses that do not immediately reveal public keys. They should also maintain secure wallet practices, protect recovery phrases and monitor future security upgrades.

5. What is Bitcoin BIP 360, and how could it improve wallet security?

BIP 360 is a draft Bitcoin Improvement Proposal introducing Pay-to-Merkle-Root outputs to reduce long-term public-key exposure. However, it has not been activated, and comprehensive protection against future quantum attacks may require additional post-quantum signature mechanisms.