The password authentication method is the easiest to implement, as it is set up by default. Since all communication is encrypted, passwords are not available for eavesdroppers.
On a Unix system, password authentication uses the
/etc/shadow file, depending on how the passwords are set up. The shadow password files can be used on Linux and Solaris servers, but not on HP-UX or AIX servers.
On Windows, password authentication uses the Windows password to authenticate the user at login time.