1.3. Understanding Authentication and Authorization

After you physically secure your environment, focus on the people who access your systems and network. The next step after implementing physical security is to ensure that persons who enter your server room or have a connection to a network port are authorized to log on to the network. Logging onto the network is authentication.

1.3.1. Authentication

Authentication is the process of proving one's identity to the network environment. Typically, authentication involves typing a username and password on a system before you are granted access, but you could also use biometrics to be authenticated. Biometrics is using one's unique physical characteristics, such as a fingerprint or the blood vessels in one's retina, to prove one's identity. Figure 1-6 shows a fingerprint reader used to scan your fingerprint when logging on.

Here is a quick look at what happens when you log on to your system with a username and password. When you type a username and password to log on to a system, that username and password are verified against a database — the user account database — which has a list of the usernames and passwords allowed to access the system. If the username and password you type are in the user account database, you are allowed to access the system. Otherwise, you get an error message and are not allowed access.

Figure 1.6. A fingerprint reader is an example of biometrics used for authentication.

The name of the account database ...

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