Lock a PDF so only people with the password can open it, using AES-256 encryption, and choose whether printing, copying and editing are allowed. Or remove the password from a PDF you can already open, so you don't have to type it every time.
It uses AES-256, the strongest encryption in the PDF standard. A long password that isn't a common word keeps the file safe.
No. The tool only removes a password you know. Without it, the file can't be opened.
That file has owner restrictions. Choose Remove a password; the restrictions are removed without needing a password. Only do this for files you're allowed to change.
Everything happens in your browser. Your files are never uploaded to a server, so nobody else can see them.