Why is encryption so significant/difficult? [closed]

Question

I'm a total beginner to encryption and I don't really understand anything about it.

Let's say I had a file TOPSECRET.BIN. What if I just:

• read file byte by byte
• XOR each byte by 69
• write "encrypted" data back into file

Sure it's simple, but how is anyone ever going to know how to decrypt that?

Answer 1

The main problem is that your ciphered text will still exhibit the hierarchical structure of the cleartext. So if the cleartext was english text, the same hierarchical structure you see in the english phrases will be in the ciphered message.