Network security has been a topic of extensive research for a long time. With newer technologies coming to the field and more intelligent hackers becoming active, providing security to our data is a never ending battle. Who could forget the two famous tales of Network security breach? Some unknown hackers stole the US government databases and then the Citibank lost $10 millions because of a group of fraud hackers. With exponential growth of internet and networking, online security and network security have become more essential when a computer is connected to a public network like the Internet. Because, all the data transmitted in this process is exposed to possible hackers and thus are vulnerable.

The factors that influence the mechanisms used for securing data on networks include many aspects. They are the network’s architecture, security components, security administration setup and network security awareness in the organization.

Network security, including privacy of data or messages transmitting, should provide four services- viz. authentication of communicating parties, integrity of data, non-repudiation, and appropriate authorization. In fact, these are the objectives or the goals a network security system.

Two parties participating in a communication across a particular computer network would also want protection from the secret eavesdropper. The sender and receiver demand confidentiality, i.e. the transmitted messages make sense to only the sender and receiver. This is achieved through cryptography.

Some form of media carries data from one destination to another. The media may be telephone lines, satellite or microwaves but these Medias can easily be accessed by anyone to read the transmitted data. This problem is tackled by ‘cryptography’. The word, ‘cryptography’ in Greek means secret writing. Cryptography is at the heart of network security. It is something like codes used by intelligence agencies for various combing operations. This technology of cryptography has been used in history of right from Roman Times to the Second World War and more recently from the cold war days to the age of information superhighway.

Let us explain the basic principal of cryptography in very simple words. In cryptography, the original data or massage at the source is encrypt or encode using well defined algorithms and then decrypt or decode the cipher text to plaintext at the destination using a reverse algorithm. These encryption and decryption algorithms are referred to as ciphers. The ciphers are public and it can be available to anyone, but the keys are secret. The encrypting algorithm produces a different cipher text with a different key, which adds to another layer of security, therefore the malicious person will need to know the key.

Network security looks to be a simple term. It is also very appealing to all of us but this term carries a lot of meaning and there are various facets of network security. Perhaps there is no absolute definition of the term network security because the concept of network security will differ according to the security policy of the user or the organization.

While surfing in the web, you are typing some address to open the homepage of a website but your browser opening the wrong one. It may happen for many Netizen. Does some one doing so? A question may case in your mind. This problem is generated by some unknown Hackers. As a Netizen you must be angry about the astonishing occurrence. Now a day Hackers are not doing this kind of child’s play. But they are not sleeping like tortoise. They expand their work load and causing head ach for many giants in the field of network security. Some authentic websites are also worried about hackers. Your PC is not secured from those spy Hackers. The primer websites that related to the services like tourism, gaming and hotels are anxious about those Hackers. They developed some way to get into your system through legal operation. You would be wonder your system is using by the hackers as a proxy server and that is also anonymously. The hackers need data that stored in your system. So they steal the data from your system a leave it defenseless to other attacks. The technical logic they used in this whipping process is also interesting. As because of high speed broadband present WebPages are loaded with wicked codes. When ever you are visiting those website these iniquitous codes create an unauthorized logger. They called a ‘Key-logger’. Millions of Net users are trapped by that ‘Key-logger’ and they steal user passwords or use Netizen’s system a proxy server. This kind of attacks for a while crashes the system. And you are not in a position to recover your valuable data that stored in the system. This infection transmitter can enter to you system by a simple email also. While they are about their normal web-surfing, Netizens get an unidentified email send by the hackers. In that they are asked to click on some compromised URLs. The Netizens are oblivious to the threat while they are about their web-surfing tricks. The hacker’s infection spreading system is done in a complex chain. But website owners are innocent about that their compromise.

Hackers are doing their business depending on others well ascertain assets. A Website that provides some services like tourism, gaming, music and hotels etc. invites some advertisement. The hackers in the form of advertiser client inserted some malicious Internet protocol address in their ads to redirect the user to another site. Those WebPages are loaded with wicked codes. This continues to different level URLs until the user logout. A Trojan is used for doing this activity. It a kind of software that can salvage code words or passwords from your system and invite all the hackers to infect it. To avoid this kind of occurrence think twice of the WebPages those require software installation. Avoid new software installation from the browser. Scan your system with updated anti-virus software before downloading any program from the Internet. Never trust an email without scanning with anti-virus and enjoy a happy surfing.

Source: The Statesman, Kolkata