How To Set And Remove PDF Document Security In C#

Background

Nowadays, data theft has become more and more popular. Thus, the security of our confidential information has vaulted to the top of our concerns. For example, we will automatically think to secure an important file before we send it to recipients to prevent its content from an unauthorized access. And this is the main purpose of writing this article.

Introduction

• Setting security to PDF document.
• Changing security settings of PDF document.
• Removing security from PDF document.
• Detecting if the PDF document is encrypted.

Part 1 - Setting security to PDF document

Adding passwords

We can add two kinds of passwords to protect PDF documents, i.e. we can add a user password (also referred to as document open password), so that only users who have the password can open the document and we can add an owner password (also referred to as permissions password), so that only users, who have the password can change the permissions of the document.

User password

Result

Owner password

Result

Setting Permissions

Permissions can increase the flexibility of document security. By customizing the permission settings, we can easily allow or prevent users from editing and copying information or limit other activities like printing and form filling.