Password Salting and Key Stretching
Salting and key stretching are techniques for storing passwords so that stolen password databases are hard to crack.
What is Password Salting and Key Stretching?
A salt is a random value added to each password before hashing, so identical passwords produce different hashes and precomputed tables are useless. Key stretching applies a deliberately slow function, such as bcrypt, scrypt, PBKDF2 or Argon2, so each guess takes much longer.