Is there any reason to trust closed-source FPGA synthesis and place and route tools any more than an Intel CPU?
But if it is possible to obfuscate a program, I think it should be possible to create something on an FPGA that is secure and private.
Maybe you have any links with a good further reading on that topic?
Well, in theory it must not, because it could detect "oh, this looks exactly like one of popular Ethernet cores, so I'll bug onto those pins and have networking", but this seems like a hard task. Or, well, it could be that every pin is hooked and a secret block awaits a specifically crafted code (somehow like port knocking), but I'm not sure this is a feasible approach.