Time Running Out for Bitcoin to Mitigate Quantum Threat, 6.9 Million BTC at Risk

Not all aspects of bitcoin are vulnerable to quantum computer attacks. The process of mining, which involves adding new blocks to the blockchain, utilizes a type of mathematics known as hashing that quantum computers are unable to break. As a result, the blockchain itself and the rule that new bitcoins can only be created through mining would remain intact in the event of a quantum attack. However, ownership of bitcoins would be at risk. Bitcoin wallets are secured by a different type of mathematics that converts a private key into a public address. This math is easy to perform in one direction but virtually impossible in the other, which is what prevents unauthorized individuals from spending someone else's coins. A quantum algorithm known as Shor's algorithm can bypass this security measure, and a recent paper by Google demonstrated that such an attack could be carried out with fewer resources than previously thought. This article explores the potential consequences of a quantum attack on bitcoin and the efforts being made to mitigate this threat. Approximately 6.9 million bitcoins, representing about one-third of all mined coins, are stored in wallets whose public keys are visible on the blockchain, making them vulnerable to a quantum attack. This includes bitcoins held by Satoshi Nakamoto, the pseudonymous creator of bitcoin. The 2021 Taproot upgrade inadvertently increased the vulnerability of some bitcoins by publishing the key protecting any remaining balance at an address after a transaction. While there are proposals to address this issue, such as adding quantum-safe address types or implementing a detection system, none have gained broad support from bitcoin's core developers. The lack of a formal governance structure and the network's emphasis on decentralization make it challenging to coordinate a response to the quantum threat. Ethereum, another major cryptocurrency, has had a formal quantum-resistant program in place since 2018 and is further ahead in addressing this issue. The window to respond to the quantum threat may be closing, and it remains to be seen whether bitcoin can coordinate a successful mitigation strategy before it's too late.