It is in the test file named '/etc/passwd' that Linux usually keeps its user account details, including the one-way encrypted passwords. However, this file can be accessed with the help of different tools, which might throw security issues.
To minimize this risk, we will make use of the shadow password format that saves the account details in a regular file /etc/passwd as in the traditional method but with the password stored as a single ‘x’ character, i.e., it is not the original password that is actually stored in this file. Meanwhile, a second file /etc/shadow will have the encrypted password, along with the other relevant information, such as the account/password expiration date, etc. Most importantly, the latter file is readable only by the root account, and thus it minimizes the security risk.
To enable shadow password use the command: pwconv