Digtal Signature Security

[Airwolfr]

Good Day

I have a question in regards to Digital Signatures.

If i have signed a document and send it to someone, are they able to change this document & if so is there a way that once a document has been digitally signed it cannot be modified in any way using a pdf editor.

[Chris - PDF-XChange]

Hi Airwolf,

The Digital Signature will verify if the document has changed since applying the signature, it can be modified but then the signature will show that this is the case. Setting the security options for the document is the only way to prevent modification. In the Viewer Goto File->Document Properties and click the security tab. Change the Security Method to Password Security, a new window will open up. Compatibility is set to be compatible with the PDF software your are sending this PDF too, if they use adobe or set it to Acrobat 9.0 or later to use 256-bit encryptions.

Check Require a password to change permissions of the document, and provide a password only you know.

Below you can set whether the document is printable, and if so low or high resolution.

Changing allowed defaults to "no changes allowed", which is what you want.

Once happy with the security options click ok.

Now the PDF cannot be changed without your set password, and if you apply the Digital Signature to verify the File is in it's original state when you applied the signature, I think you'll have it locked down.

HTH.

Best
Chris

[Airwolfr]

Thanks Chris, this helps.

[Chris - PDF-XChange]

Glad to help Airwolfr.

Best,
Chris