[gizzlon]

"Is there a way to secure a bitcoin wallet on a machine someone else has root access to (either your datacenter's staff with physical access, or the people with hypervisor access to the hardware your vm is running on)?"

Probably not, _maybe_ trusted computing could help[1]. But it might secure enough if you had a special piece of hardware that stored the bitcoin-key and did all the signing operations. I believe things like these exists for Certifications and other signing-keys. I doubt VeriSign stores their root certificates on just-another-box :)

[1] In theory, TC could "anchor" your data to the hardware chip on the motherboard, and breaking it would require physical tampering.

[JoachimSchipper]

You're thinking of a hardware security module (HSM). These are standard for e.g. certificate authorities. To the best of my knowledge, they have never been used by bitcoin outfits, but that is certainly possible, in principle.

Of course, sane people don't mix HSMs and VMs.