Protect Download File

[steven54]

I built a website on a GoDaddy server. It is running Linux.
mySQL is available on the server.
I developed a program in VB.Net (VisualStudio 2010 Pro)

Lets say you have a copy of my software. Your copy of my software is unique as before compiling it I added an alpha/numeric string to it:

Q.39G!pxgNnULcVLZ.12P

The next person who receives my program will have a different alpha/numeric string as I once again compile it but this time with a different, unique string, something like this:

cryzOU.76BiuNJz&Y.06Ba

The next person to receive this program will have a newly compiled copy with a different string.

And so on.

The alpha/numeric string will be sent to the hosting web server by clicking a button on my program. I hope to get this to work in a similar way that people log into their email account. The difference is no user ID or password is required to be entered by the user. The unique alpha/numeric string will act as that and be behind the scenes when they want to download the file.

If someone de-compiles either one of these copies they will only get one alpha/numeric string that is specific to that compiled version of my program. If that entry is used too many times a query of the database will inform me. At that point I can block that specific string access to the database. Thus, that specific compiled copy of my program becomes useless as I can stop access to the database by removing that specific string's approved access and the download file is no longer available to whoever is using that specific copy of my program.

This would be similar to being locked out of your email account after x amount of failed attempts.

That is what I am hoping to accomplish. I just have no idea where to start. If there is a better way I need a starting place as I have no idea as of yet how to accomplish this. Something like, "First, you need to do this...Then do this...Then this...". That will give me a starting point with direction to a working end.

Thank you in advance!

When a door closes another door should open, but if it doesn't then go in through the window.

 

[steven54]

This is a reply from another VB.Net message board. It really describes what I hope to build much better and in fewer words.
Any suggestions on where to begin building this?
- - - - - - - - -

You would probably perform a Windows update style authentication:

your legitimate user will install the software with a key;
the software will 'phone home' with machine-specific information - the registration process;
This will give you the key used and uniquely identifiable machine information that your software accesses;
This is stored in a database;
Your web site, when a download is requested, will verify the supplied key/machine information before returning the updated program.

When a door closes another door should open, but if it doesn't then go in through the window.