Protect PDF using C#

Protect and encrypt PDF documents securing with a password

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Protect PDF features

The C# library for protecting PDF files with user or owner password. Protect PDF with 256-bit AES strongest and most secure level of encryption within the PDF format. Set additional PDF permissions for disabling editing or printing PDF. The files protected with this C# library guarantee that users' files will be under the best protection.

C# library install

ConvertAPI provides an ASP.NET C# library that allows you to perform a Protect PDF conversion with just a few lines of code. Protect PDF documents using C# programming language with no effort at all!

NuGet Terminal >
Install-Package ConvertApi

Authenticate ConvertAPI C# library

You can obtain your secret key by signing up for a free account. Once you sign up, you'll receive 250 free conversions instantly! Grab your authentication secret from the account dashboard, and authenticate the ConvertAPI C# library like this:

// get your secret key here: https://www.convertapi.com/a/auth
ConvertApi convertApi = new ConvertApi("secret_or_token");

Protect PDF using C# in no time!

Once you have your authentication in place, simply copy-paste this pdf to protect conversion code snippet into your C# project:

// Code snippet is using the ConvertAPI JavaScript Client: https://github.com/ConvertAPI/convertapi-js

// Code snippet is using the ConvertAPI Node.js Client: https://github.com/ConvertAPI/convertapi-nodejs

// Code snippet is using the ConvertAPI PHP Client: https://github.com/ConvertAPI/convertapi-php

// Code snippet is using the ConvertAPI Java Client: https://github.com/ConvertAPI/convertapi-java

// Code snippet is using the ConvertAPI C# Client: https://github.com/ConvertAPI/convertapi-dotnet

# Code snippet is using the ConvertAPI Ruby Client: https://github.com/ConvertAPI/convertapi-ruby

# Code snippet is using the ConvertAPI Python Client: https://github.com/ConvertAPI/convertapi-python

// Code snippet is using the ConvertAPI Go Client: https://github.com/ConvertAPI/convertapi-go

REM Code snippet is using the command line utility program: https://github.com/ConvertAPI/convertapi-cli

<!-- For conversions with the multiple file result please refer to this example: https://repl.it/@ConvertAPI/HTML-Form-with-multiple-file-result -->

Try the conversion online - no coding required!

You can try out advanced conversion parameters and test the conversion result online using our interactive demo tool. This tool will produce the same conversion output as if you were using the library from your solution, and it will auto-generate the code snippet for you!

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Conversion parameters

EncryptionAlgorithm Collection

Sets the encryption algorithm.

Values:   Standard40Bit Standard128Bit Aes128Bit Aes256Bit

EncryptMeta Bool

Encrypt metadata of PDF file.

UserPassword String

Sets the user password (also known as a document open password) in the output PDF document. Users will be asked to enter this password before Acrobat Reader allows them to view the PDF document.

Password String

Sets the password to open protected documents.

OwnerPassword String

Sets owner password (also known as a permissions password). Using a owner password, you can restrict printing, editing, and copying content in the PDF. Recipients don’t need a password to open the document. They do need a password to change the restrictions the owner set.

RespectOwnerPassword Bool

Enable the property if you want to respect the document's owner password and permissions. If disabled - the old owner's password and permissions will be removed by default. Setting this property requires you to enter the correct owner's password into the Password property for protected documents.

PreservePermissions Bool

Enable the property if you want to keep the document permissions unchanged. It requires you to specify the OwnerPassword. If enabled, the document permission properties will be ignored.

AllowEverything Bool

Enable or disable all permissions. The specific permissions listed below overrides this property.

AssembleDocument Bool

Enable or disable assembly of the document - insert, rotate, or delete pages and create bookmarks or thumbnail images.

CopyContents Bool

Enable or disable copy or extract text and graphics from the document.

ModifyContents Bool

Enable or disable changing the contents of the document.

ExtractContents Bool

Enable or disable extract text and graphics.

ModifyAnnotations Bool

Enable or disable adding or modifying text annotations and fill in interactive form fields.

FillFormFields Bool

Enable or disable fill-in existing interactive form fields, including signature fields.

PrintDocument Bool

Enable or disable document printing.

PrintFaithfulCopy Bool

Enable or disable printing of the document to a representation from which a faithful digital copy of the PDF content could be generated.

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