Digital Signatures / Advanced with self signed certificate

Hi, thanks for all answers.

So I guess I have to look at the settings what is "allowed" and what is not.

Basically a second signer should lead to a different hash. Anything you add
to a doc will do that, will it? Change one bit, different hash.

But adobe seems to handle it in a more clever way. I tested some cases with
my collegues.

On the other hand I regocnized that such things as hyperlinks in a pdf made
the signature invalid more strictly, but it was visible and meta data
accessible still. In that case an "older" user might fall for it and might
judge wrongly about the validity.

So in my mind I was thinking of a layer based scheme where you seperate the
document data from all operations on it so to say.
But is there a straight forward policy?

I guess there is no shortcut other then reading the manual.

Or will somebody from Adobe safe my life time? 🙂

Best

Daniel