Alright so I have some understanding of encryption and how it works. I was trying to explain it to my friend and a few others I couldn't at the time. I later came up with an analogy. 

How accurate is this without getting too in depth 

Dale, Sam, and Max are all sitting in a class room at their desks
[Dale]---[Sam]---[Max]

Dale wants to send a message to Max. Max knows this so he takes a pencil and breaks it in half handing Dale the tip so he can write the message. Max then keeps the eraser. Dale is to far away to send his message to Max so he has to send it through Sam. Dale doesn't want Sam to read the message. Dale writes his message "Hello Max" he also takes 10 random letters and mixes them in with his message so it reads "wcdqaHelloveQMaxDF" he then passes the message to Sam to pass to max. Sam then passes the message to Max. Max's special eraser only erases the random letters. So that he can read message." Max would like to reply but he only has an eraser so he can't. So Dale takes a pencil and breaks it in half and sends the tip to Max so that he can send his message.

Does this analogy work. Could I improve on it.