Make vb.net function secure on web...

I have a VB.Net exe application that has a function in it that contains my encryption method that is used through out my application. This function is used to generate all my encrypted passwords and files etc. therefore for obvious reasons I do not want this to be visible to end users. In my application this is fine as it is compiled as a .exe. However I want to now create a ASP.Net web based version of my application.

Now here comes the question, if I was to create a web version of my application then this function would be visible to the end users along with a large number of other functions that if edited could bypass security and license control. I would like to know what is the best way to keep my ASP.Net webbased version secure from tampering, or is ASP.Net not the best for this?

Really looking for some guidance on how others deal with this.

Thanks

Simon

I haven't done any ASP programming, but I believe you can run it on the server or the client. If you decrypted everything on the server and pass back only what you allow the user to see, there is no issue.

Well if you've never made a web based program before then your going to have a lot of fun. If you made a simple one it would become very obvious that it would be safe on the web if you stuck the code on the server.

If you stick the code in the .vb file then no one will be able to see it or download it unless they have access to the server.

The ASP code is processed by the server, the user only sees the HTML that it has been given. The only time you pass "code" to the browser is for client side scripts. For example, look at the source of this website, you will see the HTML even though the website is created in php, along with the client side script. ASP.Net has the ability to compile your website into libraries, just like the .exe you get in a forms application. Think its a 'web project' you need as opposed to a 'web site' in the New menu. I've only had to create 2 or 3.