4 ms·

How practical is this against an adversary with hardware access? If they can put a vampire tap on the motherboard or CPU pins, won't the alternate code paths pu

by melony 5y ago

How practical is this against an adversary with hardware access? If they can put a vampire tap on the motherboard or CPU pins, won't the alternate code paths pursued by the CPU alert them? Most computers have standardized bootloaders. This would only work if the decryption key selection computation is encrypted and homomorphic.

Nextgrid 5y ago
> If they can put a vampire tap on the motherboard or CPU pins, won't the alternate code paths pursued by the CPU alert them? I doubt this is possible in modern hardware given the bandwidth & switching speeds they operate at.
- jrockway 5y ago
  Probably possible. You're not going to connect up like 32 eBay oscilloscope probes to someone's computer and get their data, but you could build a custom RAM module that saves interesting data. Obviously there are computing devices that operate at the speed of modern day CPUs and memory -- modern day CPUs and memory! I think that these aren't widely available because if you want someone's data you can email them and say "hey I'm the CEO and I need your password right now, I'm locked out of my account!" Much easier than engineering a 4GHz logic analyzer into a DDR4 form factor.
NavinF 5y ago
That threat model is so insane that I’ll just link this instead of responding to the question: https://scholar.harvard.edu/files/mickens/files/thisworldofours.pdf https://scholar.harvard.edu/files/mickens/files/thisworldofo...
kingcharles 5y ago
In my case, after putting a loaded gun to my head I still wouldn't give the police my access codes, but after they changed strategy and threatened my wife I broke immediately. The interrogator told the judge that if he suppressed the codes they would simply move to desoldering the chips off the board and move them to another device. The judge accepted that, despite objections. (and the fact that only works if the data is not encrypted on the chips you are transplanting)
- m0ngr31 5y ago
  What country did this happen in?
  - kingcharles 5y ago
    USA.

by melony 5y ago

Nextgrid 5y ago

> If they can put a vampire tap on the motherboard or CPU pins, won't the alternate code paths pursued by the CPU alert them? I doubt this is possible in modern hardware given the bandwidth & switching speeds they operate at.

jrockway 5y ago
Probably possible. You're not going to connect up like 32 eBay oscilloscope probes to someone's computer and get their data, but you could build a custom RAM module that saves interesting data. Obviously there are computing devices that operate at the speed of modern day CPUs and memory -- modern day CPUs and memory! I think that these aren't widely available because if you want someone's data you can email them and say "hey I'm the CEO and I need your password right now, I'm locked out of my account!" Much easier than engineering a 4GHz logic analyzer into a DDR4 form factor.

NavinF 5y ago

That threat model is so insane that I’ll just link this instead of responding to the question: https://scholar.harvard.edu/files/mickens/files/thisworldofours.pdf https://scholar.harvard.edu/files/mickens/files/thisworldofo...

kingcharles 5y ago

In my case, after putting a loaded gun to my head I still wouldn't give the police my access codes, but after they changed strategy and threatened my wife I broke immediately. The interrogator told the judge that if he suppressed the codes they would simply move to desoldering the chips off the board and move them to another device. The judge accepted that, despite objections. (and the fact that only works if the data is not encrypted on the chips you are transplanting)

m0ngr31 5y ago
What country did this happen in?
- kingcharles 5y ago
  USA.