A new method called rainbow cracking has sped up the process of cracking passwords encrypted with commonly used algorithms. “Rainbow tables” contain strings of precomputed hash values covering, for example, every possible eight-digit sequence of keyboard characters. Experts say the best defense against rainbow tables is to “salt” passwords, which is the practice of appending a random value to the password before it is encrypted. Windows Vista offers a feature called BitLocker prevents rainbow cracktype attacks by encrypting the entire operating system.”]
Source: https://www.csoonline.com/article/2121265/salting-passwords-thwarts-rainbow-table-attacks.html