Local security mechanisms for Linux

Linux is an inherently secure operating system, although the system administrator might need to have a detailed understanding of the operating system to make it completely bulletproof. For local security measures, a username and password combination is required to log on to the system, providing the basis of user verification. In the past, username and password information was stored in a plain-text format, which constitutes a security risk. Today, it is far more common to use the password shadowing technique discussed earlier in this tutorial, in the section "Linux User Management Basics."

For file system security, the EXT2 file system, and others, can be used to secure the files that are held on a system.

Note that unlike Windows systems, where there are differences in the security measures and mechanisms from version to version, a Linux system used as a workstation and a Linux system used as a server utilize the same underlying operating system. Therefore, the information provided earlier about security on Linux servers is equally applicable to Linux clients.

Authentication for Linux

Linux authentication is based on a username and password combination. Without a valid user ID, it is very difficult to access a local system. Of important note is that on a Linux system, there is a root account that can be authenticated on any system. The root account is comparable to the Administrator account on Windows networks. On a Linux system, both the username and password are case-sensitive.