Decryption Computer science. Please read this first beforeattempting the problem it will help

“For all the remaining questions, we will workwith the following toy encryption scheme. It encrypts plaintextsthat consist of only uppercase letters and the underscore character(27 characters total):


Note that the underscore character is part of the alphabetand will also be encrypted. A key in this scheme consists of 4digits, each from 0 to 9. Each digit tells how much toshift one character, that is, change it to the characterthat many positions later in the alphabet. If the shift goes past’_’, then we wrap around to the beginning.

The key is applied separately to each group of 4 letters in themessage. For example, if the message HI_SALLY is encrypted with thekey 2407, the H would be shifted by 2, the I by 4, the underscoreby 0, and the S by 7. Then we would start over with the first digitof the key, shifting A by 2, L by 4, and so on. So the ciphertextwould be: JM_ZCPLE.”

  1. Give the decryption of the following messagesthat have been encrypted with the key 4127.



PLEASE show the work and do A-C thank you.