VeryPDF PDF Toolbox is a multifunction application, which can be used to merge, split, encrypt, fill PDF form, edit PDF description information, and optimize PDF under three platforms Max, Linux and Windows. In this article, I will one of its function that encrypt PDF using 128-bit strength by command line. Meanwhile you can also encrypt PDF at 40-bit by either owner password and open password.
Step 1. Install PDF Toolbox
- This software is command line version and there is also COM version available. Once downloading finishes, there will be a zip file in the downloaded folder. Please extract it to some folder then you can check usage and examples in it.
- When you run the conversion, please refer to the usage and examples as the syntax of this is a little complicated.
Step 2. Encrypt PDF
Usage: pdftoolbox <input files> [options] <-outfile output >
- When you need to encrypt PDF by 128-bit strength, please refer to the following command line template.
pdftoolbox 1.pdf -outfile 1.128.pdf -ownerpassword verypdf -key128bit
Please pay more attention to the syntax, input the full path of the PDF file that you need to encrypt, then name the output PDF file after parameter –outfile then input the password after parameter –ownerpassword.
-ownerpassword : this parameter is an order to set owner password to output PDF file.
-userpassword : this parameter is an order to set user password to output PDF file.
<input files>: a list of input PDF file names. Each input file name can occur with a handle which is useful when specify page ranges or encrypt PDF. Handles are capital letters, e.g., A=in1.pdf, B=in2.pdf.
-outfile :this parameter should be followed with the file path of output file, designed for specifying an output file name.
-key40bit : set output PDF encryption strength as 40 bits.
-key128bit : set output PDF encryption strength as 128 bits.
-permit <permissions> : permissions are applied to the output PDF only if encryption strength is specified or an owner or user password is given.
printing : allow top quality printing.
lowprinting : allow lower quality printing.
modifycontents : allow modifying contents.
assembly : allow document assembly.
copying : allow copying.
screenreader : allow screenreader.
modifyannot : allow adding annotation.
filling : allow filling interactive PDF form.
allowall : allow all the above permissions and top quality printing.
By those parameters, you can either encrypt PDF by owner password or user password by 40-bit and 128-bit. When set owner password, you can disable many options like printing, copying, filling and so on so forth. During the using, if you have any question, please contact us as soon as possible.