For the following exercises, use the incremental development methodology to implement th...

For the following exercises, use the incremental development methodology to implement the program. For each exercise, identify the program tasks, create a design document with class descriptions, and draw the program diagram. Map out the development steps at the start. Present any design alternatives and justify your selection. Be sure to perform adequate testing at the end of each development step.

Another encryption technique is called a Vignere cipher. This technique is similar to a Caesar cipher in that a key is applied cyclically to the original message. For this exercise a key is composed of uppercase letters only. Encryption is done by adding the code values of the key’s characters to the code values of the characters in the original message. Code values for the key characters are assigned as follows: 0 for A, 1 for B, 2 for C, . . . , and 25 for Z. Let’s say the key is COFFEE and the original message is I drink only decaf. Encryption works as follows:

Decryption reverses the process to generate the original message. Write an application that reads in a text and displays the encrypted text. Make sure the ASCII value resulting from encryption or decryption falls between 32 and 126. You can get the code for key characters by (int) keyChar - 65.

Write another application that reads the encrypted text and displays the original text, using the Vignere cipher technique.