a16z Crypto: The Quantum Computing Threat Landscape Has Become Highly Polarized; Both Overly Optimistic and Overly Pessimistic Views Are Misguided

BlockBeats News, January 25th, a16z Crypto published a lengthy article "Quantum Computing and Blockchain: Matching Immediacy with Realistic Threats," pointing out that the threat of quantum computing is severely polarized, and being overly optimistic or overly concerned is not correct. Currently, publicly known quantum computing advancements are far from being able to practically run the Shor algorithm to break RSA/ECDSA. However, the long-term risk cannot be completely ignored.

Quantum computing poses significantly different threat timelines to different cryptographic primitives. Encryption may be vulnerable to a "Harvest Now, Decrypt Later" (HNDL) attack, necessitating an early transition to post-quantum encryption. Signatures, on the other hand, are not easily affected by HNDL. Prematurely migrating to post-quantum signatures may instead lead to performance degradation, immature implementations, code vulnerabilities, and other new risks, warranting a cautious advancement strategy.