If you really have that level of trust issues I'd suggest colo in a different location or with a firm you trust. If you still have those issues just purchase a simple RSA token and associated software. Pre-load and be done with it. Use a BIOS password and encryption on the HDD. On some level this thread is rediculous. Unless you understand the networking and IT infastructure you should not be putting your trading machine anywhere but at your house/office. The "lets have some fun and pretend we won the lotto" type stuff gets old. Either you have it or you don't. If you have a system that makes money and needs a colo then you'll know what to do or be able to hire someone you trust. Plain and simple.