https://snap.berkeley.edu/snapsource/snap.html#present:Username=ryan.tan%40student.isb.bj.edu.cn&ProjectName=project

I made code that required two input , one is the message that you want to encrypt, another one is the key. the code will encrypt the message according to the key. you can also use the encrypted message and the key to find out the original message.

the code can only for code that contains only capital letters, and the key can’t be longer than  the message.  I will try to make the code work for all letters later