According to PANews, the potential threat of quantum computing to Bitcoin and similar networks has been a topic of recurring debate. The recent release of Google's quantum computer, Willow, has reignited discussions about its implications for Bitcoin. Despite Willow's advancements, Bitcoin users currently have little to worry about.
Bitcoin's protocol can be simplified into two main components: mining, which relies on hash functions, and transactions, which use elliptic curve signatures. Both components could theoretically be affected by quantum computing through Grover's and Shor's algorithms. However, Willow's computational power is still far from being able to impact these areas. To effectively attack Bitcoin's hash and signature systems within a reasonable timeframe, thousands of logical qubits are required. Given that several physical qubits are needed to encode one logical qubit, millions of physical qubits would be necessary. Willow currently operates with only 105 physical qubits, indicating a significant gap remains.
In the event that quantum computing power becomes sufficient, the impact on mining would be relatively limited. Grover's algorithm only accelerates the process rather than reversing the hash function, meaning substantial computation is still needed to find the required hash values for mining. This can be likened to the introduction of a new, powerful mining machine. However, certain address signatures, particularly older P2PK and newer P2TR methods based on public keys, require caution. Addresses like P2PKH, P2SH, P2WPKH, and P2WSH, which are hash-based, remain relatively secure. Reusing these addresses could expose public keys, posing a risk.
Developers can take action by evolving Bitcoin to incorporate quantum-resistant technologies, such as hash-based Lamport signatures. The community has already engaged in discussions about these possibilities. Quantum-resistant cryptography, like lattice-based methods, could also be introduced through soft forks. Besides developers, users can protect themselves by adopting good practices, such as changing receiving addresses frequently and avoiding address reuse. Moving assets to more secure SegWit addresses before quantum computers pose a significant threat is also advisable.
Other networks, like Ethereum, are also exploring post-quantum cryptography, which could be implemented through hard forks. Ultimately, the emergence of quantum computers will impact not only Bitcoin and other cryptocurrencies but also traditional financial systems, defense systems, and secure communication channels. While there is no immediate threat from quantum computing, maintaining good usage habits and staying informed about quantum advancements is strongly recommended.
