The PDF security tools
With PDF Extra, you get everything you need to keep your files safe and secure.
Let’s review each one more closely.
Digitally Sign: Add a digital signature to guarantee that the contents of your PDF file have not been altered since it was signed.
Validate: Part of “Digitally Sign”, this tool helps you quickly validate all digital signatures in your document. If no digital signature is present in the document, this option will be grayed out.
Time Stamp: Quickly add a timestamp to your file, which is a type of digital signature whose validity is confirmed through a server. If no timestamp is present in the document, clicking on “Time Stamp” will open up the “Server Settings” panel instead.
Server Settings: Quickly add, edit, or remove timestamp servers.
Protect Document: Set strong read-only and permissions passwords for your PDF document.