text: Decryption is similar : the decryption algorithm takes , in this example , a 128-bit block of ciphertext together with the secret key , and yields the original 128-bit block of plaintext .
simplified: Decryption is similar : the decryption algorithm takes , in this example , a 128-bit block of ciphertext together with the secret key , and output the original 128-bit block of plaintext .