Bitcoin Quantum Threat Takes Center Stage at Ethereum Conference
At ETH Denver, experts discussed Bitcoin’s vulnerability to quantum computing. Bitcoin’s SHA-256 hashing algorithm is considered very resistant to quantum attacks, with Grover’s algorithm requiring infeasibly large quantum computers to pose a threat. However, Bitcoin’s digital signatures—relying on elliptic curve cryptography—are much more vulnerable to Shor’s algorithm, which could allow private keys to be derived from public keys and compromise ownership. Currently, no quantum computers exist that can do this, but recent progress by companies like Google suggests faster advancements may be possible. Estimates for the quantum resources needed to break Bitcoin’s signatures have dropped from 20 million to around 100,000 qubits. Over 6.9 million bitcoins are at risk due to exposed public keys, including many in inactive or early addresses. Solving this challenge requires both technical fixes and difficult community decisions, especially regarding older or inactive coins. Without consensus and timely migration to quantum-safe addresses, a sudden quantum attack could be catastrophic and destabilize the entire Bitcoin network.
