The program takes the input of an initial keyand an initial
vector, reads the plaintext or ciphertext from a file, conducts the encryption or
decryption, and writes the resulting ciphertext or plaintext into a second file.
test caseisas follows: using a binary initialization vector of10101010, a binary plaintext
of0000000100100011 encrypted with a binarykeyof0111111101 should give a binary
ciphertext of1111010000001011. Decryption should work correspondingly.