User Password Encryption and Cracking Techniques

In the context of frequent credential stuffing incidents caused by data breaches, the article highlights that encrypting passwords with robust algorithms can prevent attackers from recovering original passwords even if the data is leaked.

It then enumerates six typical password storage approaches: plain‑text storage, symmetric encryption (e.g., 3DES, AES), simple one‑way hash functions (MD5, SHA‑1), enhanced hash methods with salts or multiple iterations, PBKDF2, and modern memory‑hard schemes such as bcrypt and scrypt. A comparative table lists each method’s characteristics, typical attack vectors, and relative difficulty of cracking.

The discussion shifts to password cracking techniques, explaining that symmetric encryption requires the key, while hash‑based methods are vulnerable to rainbow‑table attacks. It illustrates how rainbow tables are built by pre‑computing hash chains and how chain collisions can be reduced by using varied reduction functions, effectively creating a “rainbow” of tables.

Examples of hash‑to‑plaintext tables for six‑digit numeric passwords are provided, followed by an explanation of the chain generation and lookup processes, including the use of custom reduction algorithms (R) to map hash values back to the plaintext space.

The article concludes that employing algorithms such as PBKDF2, bcrypt, or scrypt— which incorporate random salts and many iterations—significantly raises the cost of brute‑force attacks, thereby protecting user credentials even when databases are compromised.