What are the most important security elements?
Each of the elements of an effective security system operates in conjunction with the others to ensure that an organization can communicate as efficiently as possible.
The MouseOver below is a representation of the most important security elements and of the hierarchy into which these elements are organized.

When planning security, you will use a combination of

1. methods and
2. perimeter devices.

To provide access control and authentication, for instance, a system uses some combination of the methods and perimeter devices shown in the table below.

The application of internal methods for security such as auditing and the use of screening routers , firewalls, firewall tokens and remote access devices will be discussed in later modules.

1. Remote access device: Devices that have access a network from a remote site.
2. Screening router : Examines inbound and outbound packets based upon filter rules. Screening router is another term for a packet filter.
3. Firewall: A security system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both.
4. Firewall token: A string of information that identifies a specific user as packets pass through the firewall. A token is usually encrypted.