Why Use Encryption?
As organizations and individuals have connected to the Internet in droves, many have begun eyeing its infrastructure as an inexpensive 
medium for wide-area and remote connections. The Internet is an international network consisting of individual computers and computer 
networks that are all interconnected by many paths. Unlike Local Area Networks where access is physically restricted to authorized 
users, the Internet is a public network and can be accessed by anyone. It is based on a distributed model, where each site or entity manages 
its security and so there really is no 
central security.
Now more than ever, moving vast amounts of information quickly and safely across great distances is one of our most pressing needs. 
The basic idea of cryptography is to hide information from prying eyes. On the Internet this can be your credit card numbers, bank 
account information, health/social security information, or personal correspondence with someone else.
History of Encryption
Encryption pre-dates the Internet by thousands of years. Looking back in history we find that 
Julius Caesar was an early user of 
cryptography. He sent messages to his troops in a simple but ingenious method. A letter in the alphabet was replaced by one say 5 
positions to the right. So, an "
A" would be replaced by an "
E", "
B" by 
"
F" and so on. Hence 
RETURN would become 
VJYZVS. But as it can be seen, this cipher 
can be easily broken by either figuring out a pattern, by brute force or by getting ones hands on a plaintext and ciphertext 
combination to deduce the pattern.
Users of Encryption
A few decades ago, only governments and diplomats used encryption to secure sensitive information. Today, secure encryption on the 
Internet is the key to confidence for people wanting to protect their privacy, or doing business online. E-Commerce, secure messaging, 
and virtual private networks are just some of the applications that rely on encryption to ensure the safety of data. In many companies 
that have proprietary or sensitive information, field personnel are required to encrypt their entire laptops fearing that in the wrong 
hands this information could cause millions of dollars in damage.