Quantum Computing Threat Endangers One-Third of Bitcoin Supply

A growing quantum computing threat puts roughly 6.9 million Bitcoin—approximately one-third of the total supply—at risk of theft. While the network's mining process remains secure due to the nature of hashing, the cryptographic methods protecting wallet ownership are vulnerable to Shor's algorithm, which can derive private keys from public addresses. Recent research, including a paper from Google, suggests that quantum attacks may require significantly fewer resources than previously estimated. This accelerates the timeline for a potential breach, placing early Bitcoin holdings and wallets that have previously spent funds in the danger zone, as spending reveals the public key. The at-risk pool includes approximately 1 million BTC held by the network's pseudonymous creator, Satoshi Nakamoto. Furthermore, the 2021 Taproot upgrade inadvertently increased exposure; any Bitcoin spent since the activation of Taproot has published the key protecting the remaining funds at that address. The lack of a centralized upgrade path for Bitcoin contrasts sharply with its primary competitor, Ethereum. The Ethereum Foundation has maintained a formal quantum-resistant program since 2018, utilizing dedicated teams to map security migrations across upcoming network changes. While community proposals like BIP-360 exist to introduce quantum-safe address types for Bitcoin, the network has yet to implement a formal, coordinated migration strategy to protect its most vulnerable assets.