NETWORK SECURITY

NETWORK SECURITY

ABSTRACT:

A computer network is simply a system of interconnected computers. How they're connected is irrelevant. Over the last 25 years or so, a number of networks and network protocols have been defined and used. Some are ``public'' networks. Anyone can connect to either of these networks, or they can use types of networks to connect their own hosts (computers) together, without connecting to the public networks. For example the Internet. When you want to access the resources offered by the Internet, you don't really connect to the Internet; you connect to a network that is eventually connected to the Internet backbone, a network of extremely fast network components. This is an important point: the Internet is a network of networks -- not a network of hosts. Initially, university researchers and corporate employees mainly for sending e-mails and for printer sharing purposes used computer networks. Hence, security was not of great concern. But now millions and millions of people is using networks across the globe, for various purposes including banking, insurance, taxes etc. As a result security has become the need. Security is concerned with the people trying to access remote services that they are not authorized for.

Network security is a complicated subject, historically only tackled by well-trained and experienced experts. Network security problems can be divided into four closely intertwined areas: secrecy, authentication, nonrepudiation, and integrity control. Secrecy (Confidentiality) deals with keeping information out of the hands of unauthorized users. Authentication deals with determining whom you are talking to before revealing sensitive information or entering into a business deal. Nonrepudiation deals with signatures to prove your identity. Using registered mail and locking documents up achieve integrity and secrecy. Then comes authentication. People authenticate other people by recognizing their faces, voices and handwriting. However, this cannot happen electronically. Furthermore, each layer of the OSI model contributes differently. Thus, user authentication and nonrepudiation are dealt with in the application layer of the OSI model.

Cryptographic methods deal with transmitting data secretly, that is, sending the data in such a way that nobody can access it or modify it. Here, in communication security, we deal with getting the data secretly and without modification from source to destination. To ensure this type of security, different techniques are used namely, IPsec, firewalls, VPN, etc. IPsec is the long-term direction for secure networking. It provides a key line of defense against private network and Internet attacks, balancing security with ease of use. VPNs provide a more active form of security by either encrypting or encapsulating data for transmission through an unsecured network. These two types of security—encryption and encapsulation—form the foundation of virtual private networking. However, both encryption and encapsulation are generic terms that describe a function that can be performed by a myriad of specific technologies. A 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. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.

There are different techniques of security for different wireless media. Here our focus is on blue tooth. Bluetooth wireless technology is designed to replace cables between devices, such as printers, keyboards, and mice. A Blue tooth device can transmit through walls, pockets, and briefcases. There are three modes of security for Blue tooth access between two devices. Mode 1: non-secure, Mode 2: service level enforced security, Mode 3: link level enforced security. The different threats for Blue tooth such as blue jacking, blue bugging, bluesnarfing, etc. have been discussed. The usage of personal identification number (PIN) for ensuring security is a key issue been discussed.

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