> ## Documentation Index
> Fetch the complete documentation index at: https://docs.pdfshift.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Adding protection to PDF

You can restrict access to your generated document using the following rules.
The encryption is made in 128bits.

<Warning>
  Some PDF Reader don't make the distinction between user and owner in a PDF Document.
  This means that when the user password has been entered, some PDF reader ignore the restrictions (no print, no copy, etc).
</Warning>

So, setting a blank password for the user is similar to no security.

| Parameter       | Type    | Default | Description                                                                                                                 |
| --------------- | ------- | ------- | --------------------------------------------------------------------------------------------------------------------------- |
| author          | String  | null    | Document's author name                                                                                                      |
| user\_password  | String  | null    | A user who has the password will be able to view the document and perform operations allowed by the permission options      |
| owner\_password | String  | null    | A user who has the password will have unlimited access to the PDF, including changing the passwords and permission options. |
| no\_print       | Boolean | false   | When set to true, printing will be disabled.                                                                                |
| no\_copy        | Boolean | false   | When set to true, the possibility to copy any text will be disabled.                                                        |
| no\_modify      | Boolean | false   | When set to true, the possibility to modify the document will be disabled.                                                  |