Re: [PATCH] let Net Devices feed Entropy, updated (1/2)

[daw@mozart.cs.berkeley.edu (David Wagner)]

Andi Kleen  wrote:
>It is not that they are hard to fix; e.g. a $10 sound card
>with a noise generating circuit on input and a small daemon to feed
>/dev/audio to /dev/random can do it; [...]

This is a good idea, but do note that you have to be a little careful:
there are lots of ways that the result can look random enough to fool
/dev/random's entropy count but be non-random enough to provide much
less entropy than you'd otherwise expect (e.g., 60Hz effects, etc.).

I think it's a workable approach, and I warmly recommend using a broad
diversity of entropy sources (including, e.g., soundcards), but you just
have to be careful to avoid some of the pitfalls.