Re: Why are ICs always in large packages, how is this dot powered?
It could be theoretically possible. Physically possible, not sure.
An inbuilt thermocoupler could potentially provide enough power for such a small chip to do its work, depending on what exactly the "work" is.
El Reg has detailed before how its possible to snoop on CPU proceeses using the innate sounds the CPU makes, especially when dealing with RSA keys. El Reg have also detailed other hacking methods based on sound from other input devices as well.
So this chip could potentially be listening in for those sounds in order to get a hold of those keys to help facilitate hacking from an external source based on the RSA keys it "heard" .
The exfiltration of those keys is where it starts to get tricky, especially if it has no tracks to any comm ports of any style.
Could the chip then also use sound to broadcast those keys at a specific, seperate frequency that could be picked up by a mic placed somewhere in the data centre by a spy/bought agent, or even just a mobile phone connected to a powr source and secreted under a floor tile or roof panel? Maybe.
Theoretically, its possible, based on existing technology and methods, it's just whether all this stuffed into a ridiculously small package is technically possible at this stage of micro-electronics is the question.
After all, what better way to completely throw off suspicion than to include such a chip, but not have it connected to anything?