The emergence of quantum computers poses a significant threat to Bitcoin's security. Although such computers do not yet exist, developers are proactively considering upgrades to defend against potential quantum attacks. Recent research by Google suggests that a sufficiently powerful quantum computer could breach Bitcoin's core cryptography in under nine minutes, sparking concern among analysts who predict this threat could materialize by 2029. Approximately 6.5 million bitcoin tokens, valued at hundreds of billions of dollars, are vulnerable to quantum attacks, including coins belonging to Bitcoin's creator, Satoshi Nakamoto.
The potential compromise would undermine Bitcoin's fundamental principles of 'trust the code' and 'sound money.' To mitigate this risk, several proposals are under consideration, including BIP 360, which removes public keys from the blockchain, and hash-based post-quantum signature schemes like SPHINCS+ and SLH-DSA. Other initiatives, such as Tadge Dryja's Commit/reveal scheme and Hourglass V2, aim to protect transactions in the mempool and slow the spending of old coins, respectively.
While these proposals are still in development, the ongoing efforts to address quantum threats demonstrate the community's commitment to ensuring Bitcoin's long-term security.