| 1.1 |  | Overview of Network Security |
| 1.1.3 |  | The goals of network security |

| The increasing dependence of businesses and organizations on networked applications and the Internet, along with the convergence of voice with data, increases requirements for highly available applications. System downtime of any sort may result in huge revenue losses, lack of credibility, and lower customer satisfaction. Figure shows how much it can cost a business due to poor security.

There are three primary network security goals:

- Confidentiality
- Integrity
- Availability

Confidentiality
Confidentiality refers to the protection of data from unauthorized disclosure to a third party. Whether it is customer data or internal company data, a business is responsible for protecting the privacy of its data.
All customers possess the right to have their private information protected. In many cases this is a legal requirement. It is in the best interest of a business to maintain a trustworthy relationship with its customers by respecting their right to the privacy of their information.
The proprietary information of a company, which is sensitive in nature, also needs to remain confidential. Only authorized parties should be granted access to information that has been identified as confidential. Furthermore, the transmission of such information should be performed in a secure manner, to prevent any unauthorized access en route.

Integrity
Integrity refers to the assurance that data is not altered or destroyed in an unauthorized manner. For example, integrity is maintained when the message sent is identical to the message received. Even for data that is not confidential, measures must be taken to ensure the integrity of the data.

Availability
Availability is defined as the continuous operation of computing systems. Applications require differing availability levels, depending on the business impact of downtime. For an application to be available, all components must provide continuous service. These components include application and database servers, storage devices, and the end-to-end network.

These three primary goals seem very simple. However, the challenge of securing the network while taking business needs into consideration can be a very difficult task .