How Quantum Computing Will Transform Brute-Force Attacks: Grover’s Algorithm and Cryptographic Vulnerabilities.

On classical computers, brute-force attacks on symmetric encryptions require O(N) op erations. However, [1] Grover’s algorithm provides a quadratic speedup on quantum com puters, requiring only O(√N). One of the best ways to remain secure in a post-quantum world is by doubling key lengths or using AES-256, which is considered “quantum-resistant.” However, practical implemen tations of Grover’s algorithm are far beyond current quantum hardware capabilities.