Digital signatures authenticate and safeguard information by allowing authors and key personnel to "sign" electronic documents with a unique electronic signature based upon the certificate that identifies the person who applied it as having read, reviewed or contributed to the document.
D2S Sign&Validate offers a simple yet user-friendly way to sign and/or validate a PDF file without the need for a full Acrobat license.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.