1. The S-DES system must allow manual input for both encryption and decryption so
the program can be properly tested.
2. The inputs for encryption are 8-bit plaintext and 10-bit key both in binary form.
The output is 8-bit ciphertext.
3. The inputs for decryption are 8-bit ciphertext and 10-bit key both in binary form.
The output is 8-bit plaintext.
A sample test data:
10 bits key: 1000100011, P=00100100, K1=10100010, K2=00011011, C=00001010