ocr: Plainteott 5 E. S Pal Ciphertext Figure 2: Tuo rounas ofthe DES the: most ramos bOcR cibher I bas the Feistel structure E denotes the. inear eNDAnStON of the, 32 iput bils to-18input bils, e denotes tbe bifwvise XOR wito the round laey, S IS the: nontinear substittation. and P Is Ihe bil, permutation.