To help understand encryption better, we have come up with a few simple encrypters that should give you a better idea of what encryption is all about. Normally these encrypters would not be used because they are somewhat simple to break. Here they are used as examples.
This type of encryption will reverse the whole message. Thus, when the message has been encrypted the words will appear backwards. Using this form of encryption, if someone was to look at this encrypted message long enough, it would be easy to see that there is a message written backwards.
The Shifter is another form of simple encryption. Here, letters are incremented by one so a becomes b, b becomes c, c becomes d, and so on. It is easier to see a message when it has been reversed than when the letters have been incremented. However, when looking for encrypting patterns, it will still be quite easy to see when a person has simply incremented their letters, therefore this is also a weak form of encryption.
Another type of encryption is done by flipping every two characters. That is, the 1st and 2nd letters are switched, the 3rd and 4th letters are switched, the 5th and 6th letters are switched, and so on. Again, this type of encryption is very easy to decipher, so it would not be used when passing top secret messages.
One of the first types of encryption was made by Julius Caesar. This type of encryption was seen in the history.
The problem with Caesar's encryption is that it can easily be broken. One can look for the letters that most frequently appear in english (for example the vowels) and look for the letters that most frequently appear in the encrypted message. These letters are probably the vowels of the real message. Once this is done, a pattern can usually be spotted as to which letters in the encrypted message are being used to replace the real letters. This is the problem with all of the above encrypters. All encrypters that use letters to replace other letters have this problem.
Many new types of encryption were made throughout history to fix this problem. One type of encryption that does not have this problem and is very hard to crack is public key encryption. If you continue with these lessons, you will soon see why.
