Analysis: 128-bit symmetric encryption remains secure; quantum computing poses the main threat to asymmetric cryptography.

Cryptography engineer Filippo Valsorda points out that the impact of quantum computing on current encryption systems is mainly concentrated on asymmetric algorithms (such as ECDSA and RSA), while its impact on symmetric encryption (such as AES and the SHA series) is limited. Grover's algorithm does not significantly weaken the security of 128-bit keys in practical scenarios. Although Grover's algorithm can theoretically accelerate brute-force attacks, it is difficult to parallelize, making actual attacks extremely costly. Even under ideal quantum computing conditions, the resources required to break AES-128 far exceed the cost of attacking elliptic curve cryptography using Shor's algorithm. Furthermore, standards organizations, including the National Institute of Standards and Technology (NIST), unanimously agree that AES-128 still meets post-quantum security requirements and does not need to be upgraded to a 256-bit key. Industry experts believe that focusing resources on replacing quantum-vulnerable asymmetric encryption schemes is the more pressing task at present.