 If an unencrypted version of the same audio is known the random number stream can be easily retrieved and from it the key parameters can be determined, rendering every ADX encrypted with that same key decryptable.The encryption method attempts to make this more difficult by not encrypting silent blocks (with all sample nybbles equal to 0), as their scale is known to be 0.Even if the encrypted ADX is the only sample available, it is possible to determine a key by assuming that the scale values of the decrypted ADX must fall within a "low range".