Here is another encryption/decryption exercise. For this exercise, I have provided a word that will serve as the key.
To get you started: Easy = GXTW (Once you figure out the pattern to this, you can do the following):
3a. Encrypt this plaintext:
Cryptography is the art of secret writing.
3b. Decrypt the following ciphertext:
ALVAC KPLNV GGIEU RJBXY AVPSR OBAVF DC