23 ms·
Most Intel and AMD CPUs in the last 8 years have had hardware RNGs that are based on shot noise of a reverse biased Zener diode, which is better than whatever t
by RachelF 5y ago
Most Intel and AMD CPUs in the last 8 years have had hardware RNGs that are based on shot noise of a reverse biased Zener diode, which is better than whatever thermal noise/RF this resistive setup is picking up.
- nullc 5y agoThey have a hardware RNG but it sure isn't based on a reverse biased diode. They claim to be ring oscillator based, though their operation is not independently verifiable. Their design-- using AES as a whitening postprocessing step-- would make it extremely easy for them to return something like an aes stream based just on a counter and secret key as a result of an almost undetectable attack.
- kurisukun 5y agoIn a way, the system does not guarantee there is no kleptographic attack either since the CPU acts like a black-box device
- nullc 5y agoTrue enough, though the AES DRBG output based HWRNGs would be a great target-- a highly specific nobus or near nobus attack with just a dopant change breaking a single gate... and then the RNG is just some fixed AES stream known to the attacker.
- RachelF 5y agoGood to know, I assumed they'd use the best available: https://en.wikipedia.org/wiki/Noise_generator https://en.wikipedia.org/wiki/Noise_generator
- nullc 5y agoAFAIK you can't just put a reverse bias diode generator in a processor because it requires a different process and relatively high voltages (as ICs go).