You can secure a PDF using any of the following security methods:
- Add passwords and set security options to restrict opening, editing, and printing PDFs.
- Encrypt a document so that only a specified set of users has access to it.
- Save the PDF as a certified document. Certifying a PDF adds a (visible or invisible) certifying signature that lets the document author restrict changes to the document.
- Apply server-based security policies to PDFs (for example, using Adobe LiveCycle Rights Management). Server-based security policies are especially useful if you want others to have access to PDFs for a limited time.
You can also use security envelopes to protect your PDF documents in transit, as outlined in the "Exploring on your own" section at the end of this exercise.
In the next part of the exercise, you'll add password protection to a file and you'll certify a document to approve its contents.