Removing protection (password and security permissions) from existing PDF document using ByteScout PDF SDK
This example demonstrates how to remove protection and security settings from existing PDF document using ByteScout PDF SDK

Program.vb:
VB

'*******************************************************************
'       ByteScout PDF SDK
'                                                                   
'       Copyright © 2016 Bytescout, http://www.bytescout.com        
'       ALL RIGHTS RESERVED                                         
'                                                                   
'*******************************************************************

Imports Bytescout.PDF

''' <summary>
''' This example demonstrates how to lock the document with a password. 
''' PDF format supports two kinds of passwords: owner and user password.
''' User password allows to view document and perform allowed actions.
''' Owner password allows everything, including changing passwords and permissions.
''' </summary>
Class Program

    Shared Sub Main()

        ' Create new document
        Dim pdfDocument = New Document()
        pdfDocument.RegistrationName = "demo"
		pdfDocument.RegistrationKey = "demo"
        ' Add page
        pdfDocument.Pages.Add(New Page(PaperFormat.A4))


        ' Set document encryption algorythm
        pdfDocument.Security.EncryptionAlgorithm = EncryptionAlgorithm.RC4_40bit
        ' Set various user permissions
        pdfDocument.Security.AllowPrintDocument = False
        pdfDocument.Security.AllowContentExtraction = False
        pdfDocument.Security.AllowModifyAnnotations = False
        pdfDocument.Security.PrintQuality = PrintQuality.LowResolution

        ' Set owner password
        pdfDocument.Security.OwnerPassword = "ownerpassword"

        ' Set user password
        pdfDocument.Security.UserPassword = "userpassword"


        ' Save document to file
        pdfDocument.Save("result.pdf")

        ' Cleanup 
		pdfDocument.Dispose()

        ' Open document in default PDF viewer app
        Process.Start("result.pdf")

    End Sub

End Class 

Program.cs:
C#

//*******************************************************************
//       ByteScout PDF SDK		                                     
//                                                                   
//       Copyright © 2016 ByteScout - http://www.bytescout.com       
//       ALL RIGHTS RESERVED                                         
//                                                                   
//*******************************************************************

using System.Diagnostics;
using Bytescout.PDF;

namespace PasswordsAndPermissions
{
	/// <summary>
	/// This example demonstrates how to lock the document with a password. 
	/// PDF format supports two kinds of passwords: owner and user password.
	/// User password allows to view document and perform allowed actions.
	/// Owner password allows everything, including changing passwords and permissions.
	/// </summary>
	class Program
	{
		static void Main()
		{
			// Create new document
			Document pdfDocument = new Document();
			pdfDocument.RegistrationName = "demo";
			pdfDocument.RegistrationKey = "demo";
			// Add page
			pdfDocument.Pages.Add(new Page(PaperFormat.A4));


			// Set document encryption algorythm
			pdfDocument.Security.EncryptionAlgorithm = EncryptionAlgorithm.RC4_40bit;
			// Set various user permissions
			pdfDocument.Security.AllowPrintDocument = false;
			pdfDocument.Security.AllowContentExtraction = false;
			pdfDocument.Security.AllowModifyAnnotations = false;
			pdfDocument.Security.PrintQuality = PrintQuality.LowResolution;
			
			// Set owner password
			pdfDocument.Security.OwnerPassword = "ownerpassword";
			
			// Set user password
			pdfDocument.Security.UserPassword = "userpassword";
			
			
			// Save document to file
			pdfDocument.Save("result.pdf");

			// Cleanup 
			pdfDocument.Dispose();

			// Open document in default PDF viewer app
			Process.Start("result.pdf");
		}
	}
} 

.