3 ms·

Why not build a thermocouple into the RAM package and program the operating system to overwrite memory with random data on detection of a sudden temperature dro

Why not build a thermocouple into the RAM package and program the operating system to overwrite memory with random data on detection of a sudden temperature drop?

deleted 3y ago
[deleted]
adhesive_wombat 3y ago
You can also pot the PCB, and/or enclose it in a physically secure enclave where if it detects ambient light, actuation of a switch, breach of a conductive trace embedded in the case around it, etc, it wipes the RAM and, depending on your paranoia levels, blows the hardware up. Some key management Hardware Security Modules do this. Also this: https://en.wikipedia.org/wiki/Harvey's_Resort_Hotel_bombing https://en.wikipedia.org/wiki/Harvey's_Resort_Hotel_bombing The designer could probably have made more cash patenting his systems!
bri3d 3y ago
Using the OS to do this is unlikely to be effective; the attacker with this access could usually halt the CPU before they remove RAM. As in the article, the best mitigation against this kind of attack is memory encryption, either in hardware or software (although in software, you have to figure out how to keep your keys out of RAM). There are security oriented ICs of various types (flash, RAM, secure element) which do clear data with a tripwire in a lot of ways; some even have onboard current storage of some kind which allows them to clear all data as a "dying breath" when the package is tampered with. But COTS DDR RAM needs to be cheap and doesn't usually have this kind of threat model.
- josephg 3y ago
  > although in software, you have to figure out how to keep your keys out of RAM I think you can do this with modern “trusted computing” modules.
the8472 3y ago
That's still a reactive defense. A safer approach is to encrypt the data and keep the keys in the CPU, which is what TME (intel) and SME (amd) do. The downside is some added latency, power consumption and die area.
brookst 3y ago
How much more would you pay for hardware with this extra protection against you hacking it?
- chongli 3y ago
  I’m not important enough to be a target of this attack in the first place!
mhh__ 3y ago
Money

Why not build a thermocouple into the RAM package and program the operating system to overwrite memory with random data on detection of a sudden temperature drop?

deleted 3y ago

[deleted]

adhesive_wombat 3y ago

You can also pot the PCB, and/or enclose it in a physically secure enclave where if it detects ambient light, actuation of a switch, breach of a conductive trace embedded in the case around it, etc, it wipes the RAM and, depending on your paranoia levels, blows the hardware up. Some key management Hardware Security Modules do this. Also this: https://en.wikipedia.org/wiki/Harvey's_Resort_Hotel_bombing https://en.wikipedia.org/wiki/Harvey's_Resort_Hotel_bombing The designer could probably have made more cash patenting his systems!

bri3d 3y ago

Using the OS to do this is unlikely to be effective; the attacker with this access could usually halt the CPU before they remove RAM. As in the article, the best mitigation against this kind of attack is memory encryption, either in hardware or software (although in software, you have to figure out how to keep your keys out of RAM). There are security oriented ICs of various types (flash, RAM, secure element) which do clear data with a tripwire in a lot of ways; some even have onboard current storage of some kind which allows them to clear all data as a "dying breath" when the package is tampered with. But COTS DDR RAM needs to be cheap and doesn't usually have this kind of threat model.

josephg 3y ago
> although in software, you have to figure out how to keep your keys out of RAM I think you can do this with modern “trusted computing” modules.

the8472 3y ago

That's still a reactive defense. A safer approach is to encrypt the data and keep the keys in the CPU, which is what TME (intel) and SME (amd) do. The downside is some added latency, power consumption and die area.

brookst 3y ago

How much more would you pay for hardware with this extra protection against you hacking it?

chongli 3y ago
I’m not important enough to be a target of this attack in the first place!

mhh__ 3y ago

Money