I certainly appreciate the time you have spent trying to help me out! However, I seem to have made things more complicated than I intended by not specifically describing my circumstance.
I trade stocks online and use a specialized computer program (I will call it Program-X) to display stock charts. The program can be combined with a third party datafeed provider to receive real-time stock price data. For instance, if I load a chart to show the current price of General Motors, I can see the price of General Motors in real time as it is traded on the New York Stock Exchange. Program-X also allows me to develop customized mathematical studies that help me identify when to buy and sell.
As you can imagine, to do this, Program-X requires both inbound and outbound internet traffic to my computer so that it can communicate with the datafeed provider and thereby display price data on any particular stock.
While this in theory is not a security risk, my concern is that Program-X could take advantage of the inbound/outbound stream to send additional data (beyond that which is necessary to display a chart) to the company that makes Program-X or indeed the datafeed provider. For instance data such as the formula for one of my customized mathematical studies could also be sent in that inbound/outbound stream.
As I said in my earlier post, the obvious solution is a firewall, but the difficulty is that because Program-X has to have both inbound and outbound access to the internet, I would have to know exactly what information packets to block and what information packets to allow. This is doubly difficult because some of the packets appear to be encrypted.
I was hoping that there might be a way to solve this problem by setting up a network of two computers. One computer would have a copy of Program-X on it and could request/receive data. However I would not input any of my customized mathematical studies--the program would simply be a means of retrieving price data. This price data would then be forwarded to a second computer. The second computer would also have a copy of Program-X, but would have no way of sending outbound data and could only receive inbound data.
I can see why you suggested the VPN approach, but unfortunately, there is no way that I can establish a VPN connection directly with the datafeed provider. Even if it were possible, the VPN would only serve to protect against interception of the stream and wouldn’t preclude Program-X sending proprietary data—it would only encrypt the data being sent.