Adds AES-256 encryption: the file cannot be opened without the password you set. Permissions such as printing and copying can be blocked as well.
In practice: (1) Send the password through a different channel than the file. (2) 256-bit AES is what banks and lawyers expect. (3) Keep an unencrypted master copy for your own archive.
Frequently asked questions
Can the password be cracked?
AES-256 is effectively unbreakable when the password is strong. Weak passwords are the real weakness.
How do I send the password safely?
Use a different channel — SMS or a call — never the same email as the PDF.
Do it in the full tool
Open Protect PDF for all options, or jump straight to another step below.