[Cryptography] Fwd: [IP] 'We cannot trust' Intel and Via's chip-based crypto, FreeBSD developers say

[John Kelsey]

On Dec 14, 2013, at 1:49 AM, ianG <iang at iang.org> wrote:
...
> That would be to reinvent Yarrow?
> 
> If that were known as Linux's approach, and RDRAND where spiked, it would be a simple matter to spike the RDRAND in microcode again (a known/suspected capability).
> 
> Perhaps to unXOR the contents of the previous instruction and XOR in the secret stream...

You are assuming a way, way more complicated and specialized bit of malevolent engineering in the RNG chip, at that point--one that only works on one OS RNG, and one that probably breaks every time there's an OS upgrade that touches the RNG.  

Also, I have to guess that the CPU designer could find hundreds of easier ways to screw over my security.  What OS-based RNG could withstand having the CPU it's running on designed to defeat its security?  

> iang

--John