Bitcoin quantum computing risk centers on major exchange wallets, Glassnode data shows

A notable development has hit the crypto markets. Cryptocurrency exchanges are emerging as the clearest pressure point in Bitcoin’s long-running debate over quantum computing risk, sitting on millions of coins with publicly visible cryptographic keys. Bitcoin quantum risk begins with a fundamental feature of its transaction verification: public keys are hidden until funds are spent. Once a wallet signs a transaction, the public key required to verify that signature is permanently published to the blockchain.

The risk compounds when a custodian reuses that address, leaves remaining balances in it, or continues directing deposits to wallets that should have been retired. That exposure has reached a massive scale, with Glassnode noting that about 6. 04 million Bitcoin, representing 30.

Market Dynamics

2% of the asset’s circulating supply, are currently held in wallets with exposed public keys. Bitcoin Supply by Quantum Safety (Source: Glassnode) In Glassnode’s framework, public key exposure becomes the core metric for identifying wallets that would matter most in a future quantum-attack scenario. The data does not imply an immediate threat because quantum computers remain years away from the scale required to break Bitcoin’s encryption.

However, the metric reveals exactly where the network’s vulnerabilities are concentrated if advances in quantum hardware eventually make public-key exposure a practical security concern. According to Glassnode, roughly half of all Bitcoin held by labeled exchanges is susceptible under the firm's public-key visibility framework, compared with less than 30% of the non-exchange supply. Notably, the exposure breaks down into two distinct categories, with the largest being operational risk.

This bucket covers 4. 12 million Bitcoin and is tied directly to poor wallet management decisions, such as address reuse and partial spending without proper rotation of change outputs. Exchanges account for a significant portion of this risk, holding about 1.

Market Impact

66 million exposed Bitcoin, equal to more than 8% of the total issued supply. Moreover, data suggests custody standards are slipping as trading platforms expand their wallet infrastructure, deposit systems, and liquidity operations. The share of exchange-held Bitcoin considered operationally safe has steadily fallen from about 55% in 2018 to roughly 45% today.

That makes Bitcoin wallet security a measurable custody issue rather than a theoretical protocol debate. Quantum Computing operationally Safe Bitcoin Wallets (Source: Glassnode) Crypto exchanges vs Wall Street vs Sovereign wallets A broader look at the data reveals that public-key exposure is wildly uneven across the global financial landscape, fracturing sharply along the lines of crypto-native platforms, traditional Wall Street institutions, and nation-states. The clearest gap appears in crypto exchange wallets, where address reuse and legacy infrastructure leave large balances more visible on-chain.

Within the crypto sector alone, security standards vary drastically. Binance, the world’s largest crypto exchange by volume, holds 85% of its labeled Bitcoin balances in addresses where public keys have already been revealed, Glassnode found. With users holding more than $40 billion in Bitcoin on the platform, per DeFiLlama data, that methodology places over $34 billion of those assets squarely in the exposed category.

Crypto markets are watching this development closely as investors weigh its potential impact on prices.