Simple and complex encoding

letter and number substitution

     In this chapter you will learn how to use simple and complex letter substitution to help encrypt your messages.  Letter substitution has been dated back all the way to Julius Caesar Emperor of Rome. Letter substitution can be either a simple or complex method to encrypt your messages as it can work 2 ways. For instance if you wanted to encrypt a date and time you would simply replace the numbers with letters such as 5/21/2017 would encrypt to F/CB/CABH. How did i know what letters represented numbers? Its simply in a standard, and simple letter substitution A=0 which means B=1 and C=2 and so forth. This is the key to making a simple letter substitution complex. So allow me to demonstrate what i mean 5/21/2017 would encrypt to A/BA/BJAG. This is the same date in the previous example however for the encryption key I set A to equal 1. Since we are dealing with number substitution the key can go from 1-0 so a through A-G or A- I in the case of the previous example since A=0 which means the 9th letter would have been I instead of G. As you saw just by changing the encryption key we turned a simple encryption into a complex encryption. Now let's try letter substitution. 

     In letter substitution the same rules apply as with the number substitution except with letter substitution you can make things twice as complex and uncrackable which is the goal of encryptions. For example if I took the sentence "Mary had a little lamb" and encrypted it replacing letters with numbers and using A=0, the sentence would look like this "12'0'17'24 7'0'3' 0 11'8'19'19'4 11'0'12'1". In a simple letter substitution A would equal 0 so the numbers would range from 0 to 25.  This is one of the most common forms of encryption and one of the easiest types of encryptions to learn.