All of the remaining questions involve the following toy encryption scheme. It encrypts plaintexts that consist of only

[answerhappygod]

All of the remaining questions involve the following toyencryption scheme. It encrypts plaintexts that consist of onlyuppercase letters and the underscore character (27 characterstotal):
ABCDEFGHIJKLMNOPQRSTUVWXYZ_
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 2417, the H would be shifted by 2, the I by 4, the underscoreby 1, 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: JMAZCPLE.
Question # Recall that in the lecture it wassaid that any symmetric encryption scheme can be given by definingthree algorithms, G, E, and D. Thisincludes the primitive scheme you used in the preceding problems.Rewrite the description given before Problem 8 in this way, givingdefinitions of the three algorithms G, E, andD. You may use English to describe the algorithms, butgive the definition as an equality (=) and use variables torepresent the plaintext, ciphertext, and key.