I've seen that technique before used on email. Someone had a way to take a certain kind of signed email and modify it, then they had found a way to add garbage to the end of the message in such a way that either the original signature still worked, or they could generate a valid signature (don't recall which)
Of course the recipient would see the garbage, whereas a computer ignores junk at the end of an app. Maybe this was some variation on that.
I work for the Department of Redundancy Department
