Hashed and Salted

Passwords are often described as “hashed and salted”. Salting is simply the addition of a unique, random string of characters known only to the site to each password before it is hashed, typically this “salt” is placed in front of each password.

The salt value needs to be stored by the site, which means sometimes sites use the same salt for every password. This makes it less effective than if individual salts are used.

The use of unique salts means that common passwords shared by multiple users – such as “123456” or “password” – aren’t immediately revealed when one such hashed password is identified – because despite the passwords being the same the salted and hashed values are not.