I have a question about security of a file on a webserver. I have a file on my webserver which is used by my webapplication. It's a bitcoin wallet. Essentially it's a file with a private key in it used to decrypt messages.

Now, my webapplication uses the file, because it's used to recieve transactions made trough the bitcoin network. I was looking into ways to secure it. Obviously if someone has root access to the server, he can do the same as my application. However, I need to find a way to encrypt it.

I was thinking of something like this, but I have no clue if this is actually going to work:

1. Client logs in with some sort of client certificate.
2. Webapplication creates a wallet file.
3. Webapplication encrypts file with client certificate.
4. If the application wants to access the file, it has to use the client certificate.

So basically, if someone gets root access to the site, they cannot access the wallet. Is this possible and does anyone know about an implementation of this?

Are there any problems with this? And how safe would this be?