Quantum Risk Looms Large for Bitcoin's Most Vulnerable Coins

Quantum computing has long been a topic of interest and concern within the cryptocurrency space, particularly when it comes to the security of digital assets like Bitcoin.

A recent analysis by Glassnode sheds light on the potential risks associated with quantum attacks on Bitcoin's network, highlighting that nearly 30% of its total supply – approximately 6.04 million coins – is vulnerable due to exposed public keys.

The majority of these coins are tied to old address formats, such as pay-to-public-key (P2PK) addresses, which were commonly used in the early days of Bitcoin. These addresses inherently expose the public key, making them susceptible to quantum attacks if a powerful enough computer is developed.

Another significant contributor to this risk is the reuse of addresses in transactions, particularly by exchanges and institutional players. This operational exposure accounts for approximately 20% of Bitcoin's total supply, with about 1.63 million coins tied to exchange-related balances.

The practical implications of this analysis are clear: holders should avoid reusing addresses and consider moving funds to modern address types like pay-to-witness-public-key-hash (P2WPKH) or pay-to-taproot (P2TR), which do not expose the public key until a transaction is initiated.

Institutional players and exchanges are also encouraged to reassess their practices, including implementing better key rotation policies and avoiding address reuse. This could significantly reduce the risk surface associated with exposed public keys.