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Internet Security – Password Based Authentication and Prevention of Dictionary Attacks


Abstract
Today, the World Wide Web is used for information, commerce, news, weather, music, telephony, audio and video conferencing, database access, file sharing, with new features cropping up almost daily. Each has its own security concerns and weaknesses. The frequency and sophistication of Internet attacks have increased. These changes in the Internet community and its security needs prompted the first bona fide defense measures. The network must be protected from outside attacks that could cause loss of information, breakdowns in network integrity, or breaches in security. As the Internet has matured, however, so have the threats to its safe use, and so must the security paradigms used to enable business use of the Internet. This paper summarizes a multi-dimensional approach (which is mandatory these days to discourage ever-more sophisticated threats to the network) to security in the present scenario as against a single-dimensional approach, which is no longer adequate, and very much a popular target to attack.

Introduction
Single dimensional approach to security is unable to handle the commercialization of Internet and the changing dynamics of the attacks. Two widespread viruses—Melissa and the Love Bug—caused major disruptions of e-mail systems around the world. Business transactions when conducted over an insecure channel pose great risk and attract real criminal activity. A series of distributed denial-of-service attacks interrupted service at many high-profile sites, including Yahoo, CNN, and eBay. As against single dimensional approach, multi dimensional approach uses better security techniques thus preventing attacks that have disrupted businesses. This approach provides a defense mechanism, which gives a controlled and audited access.


Authentication – What? Why? and How?

Authentication refers to the act of verifying the identity of an entity or an object.
A computer can Authenticate humans through -
Biometric Devices such as fingerprint analyzers or retinal scanners which directly identify – who a user is
Smart Cards and physical keys that can authenticate – what the user has
And Passwords which authenticate – what the user knows