Create a digital signature

Suppose Bob wants to prove that he is Bob. He can do that by creating a digital signature, which is essentially a message encrypted using his private key.

Only Bob could have generated that encrypted message, because only he has his private key. (In this exercise, it is possible that someone else could have the same private key. But in a more complex (and realistic) setting, this is not a concern.) But anyone can use Bob's public key to decrypt the message, thereby verifying that it was Bob who signed (i.e., encrypted) it.

Enter a message below, along with Bob's private key (which is 103) and the second part of his public key (which is 143). The program will:

1. Separate the characters of your message using commas.
2. Convert the characters into ASCII format.
3. Encrypt the characters using the private key.