Well, since my post on hosting ClickOnce with Amazon S3 Storage, I've received quite a few emails asking how to secure the deployment.

At the time of this post I regret to say that there is no way to secure your ClickOnce deployment hosted with Amazon S3. The S3 storage is secured by ACL meaning that a username and password will have to be provided before access. The Amazon CloudFront, which sits on top of S3, allows you to apply security settings to your CloudFront distribution by

• Applying an encryption to the URL.
• Restricting by IP.

The problem with the CloudFront is that the encryption of the URL is mandatory. ClickOnce does not provide a way to pass the "Amazon Public Key" to the CloudFront URL (you probably can if you start editing the XML and HTML files ClickOnce generate but that defeats the porpose of ClickOnce all together).

What would be nice is if Amazon can allow users to restrict by IP addresses or IP Blocks. I'd sent them an email and received a response that this is something they are looking into...I won't hold my breadth though.

Alternative

I suggest you look at Rack Space Cloud hosting http://www.rackspacecloud.com they have very competitive pricing and recently started hosting Windows Virtual Servers. What you can do is rent a virtual server, setup IIS to host your ClickOnce applications. You can then use IIS security setting to restrict what IP/Blocks can access your ClickOnce payloads.

Note: You don't really need Windows Server to host ClickOnce. Any web server can do. If you are familiar with Linux you can run that VM with rackspace for half the price of Windows.

I hope you found this information helpful.