Consequently, "Hey" would be transmitted as "Ro$." Write a program Java that decrypts the intercepted message. You only know that the key used is a number between 1 and 100. Your program should try to decode the message using all possible keys between 1 and 100. When you try the valid key, the message will make sense. For all other keys, the message will appear as gibberish. Since there are only 100 keys this would obviously be a pretty crummy encryption system. This Programming Project will require you to explore a bit on your own how to convert from a char to a number, process the number, then convert it back to a char. See Chapter 2 for String methods. You will want to use charAt(). Important: Note that the secret code has a \ so you will need to escape encode it by using \\ if y

Question

11. Your country is at war and your enemies are using a secret code to communicate with each other. You have managed to intercept a message that reads as follows:
```
:mmZ\dxZmx]Zpgy
```

The message is obviously encrypted using the enemy's secret code. You have just learned that their encryption method is based upon the ASCII code (see Appendix 7). Individual characters in a string are encoded using this system. For example, the character ‘A’ is encoded using the number 65 and ‘B’ is encoded using the number 66. Your enemy's secret code takes each letter of the message and encrypts it as follows:
```
if (OriginalChar + Key > 126) then
EncryptedChar = 32 + ((OriginalChar + Key) - 127)
else
EncryptedChar = (OriginalChar + Key)
```
For example, if the enemy uses Key = 10 then the message "Hey" would initially be represented as:
Character ASCII code
H 72
e 101
y 121

And "Hey" would be encrypted as:
Encrypted H = (72 + 10) = 82 = R in ASCII
Encrypted e = (101 + 10) = 111 = o in ASCII
Encrypted y = 32 + ((121 + 10) - 127) = 36 = $ in ASCII

This program requires some knowledge of how to map from ASCII to integers, perform arithmetic, and map back to ASCII.

Answer 1

See the code in Decrypt.java