Adobe Reader Android - Signature Flattening

Hi there,

I am using Adobe Acrobat Reader for Android: I am wondering whether there is any way to 'lock' or flatten a signature that has been entered onto a PDF? It seems when I sign a document using a signature (either by drawing it or using a saved picture), it inserts it onto the document without a problem, but when I open it elsewhere, I am able to copy/extract the signature without any issues.

This is quite concerning: is there any way to flatten a signature so that a signature cannot be extracted?

Thank you.