Well, my guess is that the decrypted files all have the same values at those positions in the header, could be 00 00 00 00 ... or ff ff ff ff ... for example. At first I thought the Odyssey and the Orizon might have different keys for the encryption which caused these recurring strings to be different, but since the two Odyssey files look so different I guess that's not true.
Anyway, I personally think it's a good start and will keep trying
