a16z Crypto: The security focus for public blockchains like BTC and ETH should be on protocols and governance; there's no need to blindly switch to quantum attack-resistant solutions.

a16z Crypto published a lengthy article on the X platform, pointing out that the timeline for the emergence of a quantum computer capable of cracking cryptocurrencies (CRQC) is often exaggerated, and the likelihood of it appearing before 2030 is extremely low. The risk profiles of different cryptographic primitives vary. Quantum-resistant encryption faces "capture-before-decrypt" (HNDL) attacks and requires immediate deployment. Quantum-resistant signatures and zkSNARKs, however, are less susceptible to HNDL attacks; premature migration could lead to performance overhead, immature implementation, and code vulnerabilities, thus requiring a cautious rather than hasty migration strategy. For blockchains, most non-privacy public chains such as Bitcoin and Ethereum primarily use digital signatures for transaction authorization, thus posing no HNDL risk. Their migration pressure mainly stems from non-technical challenges such as slow governance, social coordination, and technical logistics. Bitcoin faces unique issues including slow governance and the existence of millions of quantum-fragile tokens worth hundreds of billions of dollars that could be abandoned. In contrast, privacy chains, due to the encryption or hiding of transaction details, do face HNDL attack risks and should transition as soon as possible. a16z Crypto emphasizes that in the coming years, implementation security issues such as code vulnerabilities, side-channel attacks, and fault injection attacks pose a more pressing and significant security risk than the threat of distant quantum computers. Developers should prioritize investing in code auditing, fuzzing, and formal verification.