In past I've heard about couple of cases where people had some startup idea that involved some clever application/algorithm that would have had to be deployed t

In past I've heard about couple of cases where people had some startup idea that involved some clever application/algorithm that would have had to be deployed to customers premises but kept secret. With slight modifications (* ) this sounds like a low cost, but easy to deploy solution to the problem. Some of the security would be lost, but you would still get a reasonably tamper proof computer that is capable of running standard software stack for <$1K. With the same kind of changes you could also build a low cost HSM solution based on this. (* ) Instead of controlling booting, the keyfob could be used to enable/disable console access and the device should be able to recover from short power losses.