Contrary to popular superstition, AES 128 is just fine in a post-quantum world

A cryptography analysis argues that quantum computers do not simply halve symmetric-key security.

Grover’s algorithm gives only a limited, hard-to-parallelize speedup, so AES-128 remains secure enough in practice.

That challenges the claim that 256-bit symmetric keys are needed to deliver 128 bits of security.

The takeaway is that organizations should focus on harder post-quantum migration tasks, not unnecessary symmetric-key upgrades.