Despite the potential threat of quantum computing to cryptocurrencies not being imminent, the Bitcoin community is actively addressing this long-term risk. The manifestation of this risk is not absolute but depends on future advancements in hardware technology and the readiness for software migration. Therefore, the current focus is more on long-term preparations, emphasizing robust engineering practices and orderly upgrade paths.
On a technical level, the core consideration for Bitcoin is to gradually strengthen or replace the existing Elliptic Curve Digital Signature Algorithm (ECDSA), while continuously monitoring the impact of quantum computing on the SHA-256 hash algorithm. This strategy guides developers on how to phase proposals and test migration plans.
In the short term, the focus of work is more on organizational aspects rather than direct operational levels. This includes clarifying governance processes, promoting migration plans, and closely tracking the latest developments in quantum computing research. When the community reaches an early consensus on standards and activation methods, the overall security posture will be significantly enhanced.
Regarding preparations, timelines, and institutional positions, post-quantum cryptography (PQC), BIP-360, and the commitments surrounding Taproot play important roles. Blockstream CEO Adam Back believes that “Bitcoin is unlikely to face cryptographically relevant quantum attacks in the next 20 to 40 years.” This timeframe prediction is based on an analysis of the reliance on error correction capabilities and scalable hardware.
Common questions regarding quantum threats, such as Galaxy Digital's comments on quantum risks and recent Bitcoin sales, have been addressed by the firm, which denies that quantum concerns are the reason for sales and emphasizes that quantum risk is a long-term issue, with recent focus needing to be on governance considerations.
As for which parts of Bitcoin are vulnerable to quantum attacks, the ECDSA signature algorithm faces long-term quantum risks, while the SHA-256 hash algorithm is less affected in practical applications. Current preparations are mainly focused on migrating the signature algorithm through soft fork proposals like BIP-360.