02-05-2014, 10:58 AM
NETWORK SECURITY
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INTRODUCTION
For the first few decades of their existence computer networks were primarily used by university researchers for sending email, and by corporate employees for sharing printers. Under these conditions, security did not get a lot of attention. But now, as millions of ordinary citizens are using networks for banking, shopping, and filling their tax returns network security is looming on the horizon as a potentially massive problem.
Information systems have evolved in the last few decades from centralized and highly secure host-based systems to be decentralized.Enterprise computing systems, in which computers and information resources are distributed throughout an organization. It is often said that in the enterprise model, “the network is the computer”.
In the 1980s uses gained important ground in the information age with the personal computer. Suddenly they could store vast quantities of information at their own desktops, rather than on centralized computers controlled by “information czars”. But of course potential for data theft, corruption, and eavesdropping increased.
TYPES OF NETWORKS
A number of single user systems and multi user systems linked together for the purpose of data and resource communications is called as network
Local area network
The name local area network (LAN) implies that the network is relatively small and with in area. Cable connects all the systems in the department of an organization .The electric characteristics of the cable often define the limits of LAN and the number of computers you can attach to it. All the users in the department trust one another (in theory at least), because all the uses are known and working the same department. Detecting the preparatory of malicious activity is possible in most cases.
In the early days of LANs, few people concerned themselves with the though that someone would tap their network cable and monitor transmissions: few people knew how to tap a cable.
INTERCONNECTED NETWORKS:
Most companies are still fairly relaxed about the way they interconnect their information systems. Network cables are open and anyone could have taped that cable on matter of minutes during the night.
The end result of these interconnected networking was a mesh of cable running in all directions. A manager and technicians had trouble keeping track of every cable run. If you ran cable through the ceiling, then you had to be wary of air -conditioning service technician who might find some reason to II tap cable .If cable was concentrated in a telephone closets, the telephone repairer was suspect.
Growing companies typically install cable through out the building and put connections in offices that are not yet occupied. Industrial spies who manage to get into your building may "set up office", posing as temporary employees or people from a branch office. They connect to the network and monitor its traffic using devices called packet snifters. Monitoring network traffic can provide vast amounts of information, such as logon names and passwords or information about the servers on your network and the types of services they provide.
WHAT ARE THE THREATS?
The biggest problem with the hacker threat is that hacking is fun!
Threats by floods and fires are easy to understand: the techniques for protecting against them area well known. But threats perpetrated by malicious users, disgruntled employees, and unknown hackers are a true nightmare. Every day some new technique for attacking systems is developed.
WHO ARE THE HACKERS
You may not know any hackers personally; On the other hand, a hacker might be your next-door neighbor’s son--someone with a computer and modem who is familiar with what you do, and who might guess your logon password because you use some derivative of your kids' names. The people who do it see hacking as an electronic sport. They will spend all of their free time breaking into systems just for the thrill of having done so. Don't try to understand why, just know that they are out there.
Dangerous hackers are very knowledgeable about computers and security techniques, and they use sophisticated techniques to break into computer systems. Your competitor may hire such a hacker. If hackers cover their tracks, you might never know that they have stolen your customer mailing list or trade secrets.
THE INTERNAL THREAT
A recent online survey by Network World magazine revealed that most security experts and readers felt that internal employees were the biggest threat to their information systems. Employees are familiar with the network, know which systems hold valuable information, and may have easy access to those systems through their own account or the account of another use. The American Society for Industrial Security estimates that 77 percent of information theft is perpetrated by insiders.
VIRUSES AND TROJAN HORESES
Viruses are small programs that mimic the activities of real-life viruses. They get into computer systems by being copied from contained disks or downloaded from online services by unsuspecting users. Once a system is contaminated, the virus executes some immediate action, or waits until a specified time or for a specific command executed by the user. Viruses may display harmless messages or destroy the information stored on entire hard disks. A Trojan horse is similar to a virus, but contaminates a system by posing as some other type of program.
PROTECTIVE MEASURES
There are a number of protective measures that help you "harden" your defenses, put up walls, and lessen the chances that someone is going to physically or electronically attack your systems. A few obvious steps are:
Create security policies, plans, and job positions as appropriate.
Set up a security-response team, experts who handle security problems. The team can provide a place for users to report security breaches or contacts by suspicious people who may be industrial spies.
Perform background checks on personnel and keep tabs on employees who are disgruntled, who are working closely with other companies, and who are in the process of leaving the company.
Classify your employees much the way the military classifies its personnel, giving some people higher clearance for access to sensitive information than others. Make sure to differentiate between part-time and temporary employees.
CONCLUSION
I conclude my seminar saying that as hackers and many algorithms are there to break passwords and much valuable information, which leads to a great loss. Hence network security provides the remedy by many ways. Hence much more advanced security measures would be more helpful. So always that should be an eye on network security as it is much and more important.