PDF
保护PDF
为PDF添加密码和权限限制。
Passwords
Set passwords to control access and editing.
Permissions
Control what recipients can do with the PDF.
Allow printing
Recipients can print the document
Allow copying text
Recipients can copy text from the document
Upload a PDF to protect with a password.
Uses 128-bit RC4 encryption. The owner password controls permission restrictions — leave blank to use the user password as owner password.