You can encrypt your PDFs with passwords when they are fully signed.
To turn on this feature you need admin permissions. Go to Admin > PDF Security . Once it is turned on everyone sending out documents can use the feature.
You can select either for us to keep the password (i.e. so it is retrievable from us later), or for us to delete it once the document is created.
If you choose for us to delete the password after it is set, if you forget the password later then it's gone for good.
At the same time, you can set a default password to use automatically, but you can always change the password on the Send page.
When you go to the Send page to send out a document you have the option to set a password for the final PDF.
The password will be shown to signers ONCE on the download page after they sign the document.
Here is a short video that shows where to turn on the PDF password feature.