I'm attempting to identify the method of encryption for a black-box symmetric encryptor that produces blocks of output that are 4 bytes in length (e.g. small inputs fit in 16 bytes, then 20 bytes and 24 bytes as more input characters are added).
It's symmetric encryption and the value is always the same for the same input text. Is it possible to determine which method of encryption is used? I'm assuming it's a block cipher as a result of the blocks of output it produces.