Creating a password locked pdf document in linux
We can user pdftk tool to create a password locked pdf file i.e. to open the pdf file we need to open the supply a password.
The options that have to be passed to pdftk are
$ pdftk output encrypt40bit user_pw
Let us say we have a file temp.pdf and we want to have the password “hello” for opening the file and we will call the new file by the name temp_passwd.pdf
$ pdftk temp.pdf output temp_passwd.pdf encrypt_40bit user_pw “hello”
Now if we try to open the file temp_passwd.pdf we will be prompted for a password and the file will open only if we pass the password “hello”.
In the command we also use encrypt_128bit instead of encrypt_40bit.