Let's say: an error is induced into an implementation of the AES-128 to produce a faulty ciphertext. The error is a one-byte eror and is always induced on the last state byte, during round9, before the
MixColumns operation. The induced errors are unknown and can be different. However the key is the same in both cases.
Then how can I recover 4 bytes of the last round key? Which bytes of that round key can I recover and what's their value?
ciphertext1 = 0xe719f8ab9e0b846f0cf2e5c32a0e5b45 faultytext1 = 0xe719f86f9e0beb6f0c97e5c38b0e5b45 ciphertext2 = 0x78f272c7cf5383085fa240236d97130f faultytext2 = 0x78f27277cf53e7085f944023fa97130f