What is creptogrphy?

Answer 1

Cryptography is the study and practice of obscuring information by writing it in a way that only a select group of people can read it.

This may be accomplished by simply substituting letters. For example, if Steven wanted to encrypt his name, he could substitute each of his letters with another letter three places further into the alphabet. This would result in "Vwhyhq". This is one of the simplest methods of cryptography and as such, one of the easiest to crack. Properly secure cryptography involves passwords and complicated algorithms and can thus only be efficiently implemented via computer.