Common Password Attack Vectors

Understanding how attackers compromise passwords is crucial for implementing effective defenses. Brute force attacks represent the most straightforward approach, where attackers systematically try every possible password combination. Modern GPU-accelerated systems can test billions of password hashes per second, making short or simple passwords vulnerable within minutes. The evolution of cloud computing has made distributed brute force attacks more accessible and affordable to cybercriminals.

Dictionary attacks optimize brute force approaches by focusing on commonly used passwords and patterns. Attackers maintain extensive databases of leaked passwords, common words, and predictable variations. These dictionaries, combined with rules that apply common transformations (like replacing 'a' with '@' or appending numbers), can crack a significant percentage of user passwords. The effectiveness of dictionary attacks highlights why password complexity requirements alone provide insufficient protection.

Rainbow tables represent a more sophisticated attack method that trades storage space for computation time. These precomputed tables map hash values to their corresponding plaintext passwords, allowing near-instantaneous password recovery for unsalted hashes. Before the widespread adoption of salting, rainbow tables could crack most passwords hashed with algorithms like MD5 or SHA-1 within seconds. The existence of rainbow tables fundamentally changed password security practices and drove the adoption of salting techniques.