What is Network Security?

Written by Vyga V R Thursday, 18 March 2010 09:08

Network Security

Computer networks are typically shared resources used by many applications for many different purposes. The data usually shared of transmitted between different computers are confidential in nature. Network security deals with the confidentiality, authentication and message is exchanged between computers on different networks or within the same network.

• Confidentiality ensures the fact that when a message is transmitted by a sender, only the intended receiver will understand the contents of transmitted message. An interceptor won’t be able to understand that message.
• Authentication means sender and receiver should be able to confirm identity of other party involved in the communication.
• Message integrity refers to the assurance that a message has not been disturbed or modified by an intruder during transmission.
• Non-repudiation means to ensure that a transferred message has been sent and received by the parties claiming to have sent and received the message. Non-repudiation is a way to guarantee that the sender of a message cannot later deny having sent the message and that the recipient cannot deny having received the message. Non-repudiation can be obtained through the use of:

1. Digital signatures—function as a unique identifier for an individual, much like a written signature.
2. Confirmation services—the message transfer agent can create digital receipts to indicate that messages were sent or received.
3. Timestamps—timestamps contain the date and time a document was composed and proves that a document existed at a certain time.

• Availability refers to protection against disruption of services. It ensures that services provided by any server system is available to all authorized users.
• Access control mechanism controls which users or computer programs can access data. Such techniques ensure that only authorized users will gain to access to resources. Appropriate access right policies should be defined first and only users having access rights will be allowed to utilize resources. For example, some systems implement an access control list foe each object that determines who is allowed to access the object. In other system each user is assigned a password. When a user needs to access protected resources, the user is asked to enter the password.