Secure PDF

Secure PDF online, by software or command line

Secure PDF

A PDF file may be encrypted for security, or digitally signed for authentication.

The standard security provided by Acrobat PDF consists of two different methods and two different passwords, user password, which encrypts the file and prevents opening, and owner password, which specifies operations that should be restricted even when the document is decrypted, which can include: printing, copying text and graphics out of the document, modifying the document, or adding or modifying text notes and AcroForm fields. The user password encrypts the file and requires password cracking to defeat, with difficulty depending on password strength and encryption method. The owner password does not encrypt the file, and instead relies on client software to respect these restrictions, and is not secure. An "owner password" can be removed by many commonly available "PDF cracking" software, including some free online services. Thus, the use restrictions that a document author places on a PDF document are not secure, and cannot be assured once the file is distributed; this warning is displayed when applying such restrictions using Adobe Acrobat software to create or edit PDF files.

You can Secure PDF by our online program, PDFConvert desktop software or command line program.

Secure PDF Online

Encrypt PDF Form
Local PDF File:
User Password:
Owner Password:
PDF Restrictions: Allows to print PDF with high quality
Allows to print PDF with low quality
Allows to modify PDF contents
Allows to copy PDF contents
Allows to edit PDF annotations and fill PDF forms

Use this form to encrypt a PDF file with user/owner password and set PDF restrictions.

1. Click "Choose File" button (different web browser may have different button name such as "browse..."), a browse window will open, select a local Adobe PDF file and click "Open" button.
2. Enter a user password if you want this PDF needs password to open. Enter an owner password if you want to set restrictions. Choose PDF restrictions from list.
3. Click "Encrypt Now!" button to convert. Wait a few seconds for the task to finish.
4. You can download or view the output PDF file on your web browser after conversion.

Secure PDF software

After installing PDFConvert software, click Start - Programs - PDFConvert - PDFConvert to run.

Click Toolbar Settings, Click "PDF Security" button on the left.

Select Enabled Password Encryption checkbox. Enter passwords to open document or passwords to edit document, select PDF restriction options, choose encryption algorithm from 40-bit, 128-bit AES and 128-bit ARC-FOUR. Leaving this page will save settings.

PDFConvert will set password and add restrictions to the PDF file when a PDF file is created from image files or documents.

The password to open PDF is called user password. The user password encrypts the PDF file and requires password cracking to defeat, with difficulty depending on password strength and encryption method. It is potentially very secure. The password to set PDF restrictions is called owner password. The owner password does not encrypt the file, and instead relies on client software to respect these restrictions, and is not secure.

Secure PDF command line

Download pdfconvert.exe, and run pdfconvert.exe command line program to Secure PDF on background without windows showed.
/?
Shows all command line parameters of pdfconvert.exe.
/i
input files
For example: pdfconvert.exe /i "c:\pdf\1.pdf"
/o
output folder
For example: pdfconvert.exe /o "c:\pdf2"
/op
Set the PDF file User password
/ep
Set the PDF file Owner password
/edt
Enable copying of text, image and other context (0: can't copy, 1: can copy)
/ept
Enable PDF printing (0: can't print, 1: can print)
/pst
Set the PDF file encryption algorithm (0: 40bit, 1: 128bit AES, 2: 128bit ARC-FOUR)
For example: This command will add user password "abcdef", owner password "123456" and restrictions to local PDF file "c:\pdf\1.pdf", and save file to "c:\pdf2\1.pdf".
pdfconvert.exe /i "c:\pdf\1.pdf" /o "c:\pdf2" /op abcdef /ep 123456 /edt 0 /ept 0