The Internet or the global Internet is the internationally connected network of computer networks with addresses that are administrated by IANA (Internet address and Naming Authority). It grew dramatically because anyone can connect to it and any one connected to it can connect others to it as well. Each site that connected to it, can become an Internet Service provider to other sites.The features that give Internet its vitality also make it unsafe, like streets of a major city. People do not walk carelessly in vital, teeming city.
A careful person approaches the Internet with caution.The essential problem is that you can make no assumptions about data you send in, receive over the Internet. Data you send could be modified by subverted routing host before it arrives at its destination. The data could be stolen and resorted to a different destination, never arriving where it should. Data youreceive could be , completely forged (or) simply modified in transit. If your data is important then there is a real risk of someone interfering with it, then you need, protection.Thus, business data that crosses the public Internet can be forged, modified and stolen.
Cryptography has emerged as the only alternative to protect Internet data and it does the job well. Modern crypto techniques have evolved from secret codes of decades past, brilliantly augmented with deep knowledge of modern mathematics. New cryptographic products and technologies have been developed particularly for Internet applications.