ASP.NET MVC send an email attachment which is a password encrypted PDF file

I am working on document storage and retrieval application.开发者_StackOverflow社区 In which i display the pdf document as an png image , but i have a email button on the top. On clicking that the user would be able to provide an email address to which the document needs to be sent, and I need to send this pdf as an attachment. I need to password protect the file for security reasons. I have no clue on how i can do this in asp.net mvc.

Password protecting a file has nothing to do with ASP.NET MVC; you would need to password protect it prior to handing it off to ASP.NET MVC for transmission to the client.

Using HTTPS would be more secure.

Password protected PDF using C#
Password protected PDF using C#

You can use a compressed, password-protected 7zip file. For added security, compress the file programmatically and set a randomly-generated password your users can only access by logging in to your website.