Encrypt your PDF with AES-256 in your browser. Add and confirm a password required to open the resulting document without uploading it.
For a private handout, enter and confirm a new password of at least eight characters. Keep an original copy and store the password securely. Download the encrypted file, reopen it in your intended PDF reader and test that the expected password opens it before sending it.
Encryption restricts opening with AES-256. Authorized readers can still see the content; use permanent redaction for selected information that must not be shared.
Drop one PDF here, or use Open PDF. Maximum 50 MB.