أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
I agree with MR Hafiz Muhammad Asif Siddique and MR padmakumar pathiyil
Encrypt the document.
Encryption
by a password
Its very easy just go to file menu then click on prepare and select option "Encrypt Document". After this save it and your file is protected