1. ## 3-stage Feistel Cipher

initial key $K_1$ = (124)(3)
firstly, i need help with finding out $K_2$ and $K_3$
then once i have those keys, i need to work out an 8-bit plaintext from the ciphertext 10011110

2. Originally Posted by wik_chick88
initial key $K_1$ = (124)(3)
firstly, i need help with finding out $K_2$ and $K_3$
then once i have those keys, i need to work out an 8-bit plaintext from the ciphertext 10011110
That is the shortest cipher text I've seen.

Since the Feistel algorithm is for both encryption and decryption, you have the end result. Plug that back into the $K_1$ round and proceed.