What are the potential limitations of Electronic Code Book (ECB)? It needs an initialization vector to operate. Repetitive information contained in the plaintext may show in the ciphertext, if aligned with blocks. If the same message (e.g., an SSN) is encrypted (with the same key) and sent twice, their ciphertexts are the same. If one ciphertext block is corrupted during the transmission, all subsequent ciphertext blocks cannot be decrypted unless until corrupted block is successfully retransmitted