Shadow Password File

A shadow password file is associated with the Linux operating system. On this platform, a user’s information and password is stored in a special system file. Stored passwords for each user are encrypted or encoded and undergo the following three steps: 1. The original password is encrypted using a randomly generated value, a one-way hash function, or an encryption key in order to achieve the state it will be stored in. The stored result is not something that can be simply entered as a password itself. 2. The key, most commonly known as the salt, is stored with the encrypted password. The key can’t be used to decrypt the encrypted password because of the one-way function. 3. When a user enters a password, it is then rehashed with the salt value and compared with the encrypted value. If the values match, the user is then granted access to the system.