Currently I am using
haveged on my server as source of entropy.
My Server is used as KVM hypervisor, to run virtual machines.
I did not use
haveged at the beginning, and I noticed the VMs were draining the entropy pool from the server. Sometimes, when VMs were started SSH waited for enough entropy (to generate session keys, I guess).
haveged, I don't have this problem anymore.
But I would like to try to use a HW random number generator. I am not saying
haveged is bad, but true HW random number generator can only make the entropy better.
I have seen some HW RNG which work on basis of Geiger counter, some which collect noise from microphone, and so on.
Which are most reasonable to use ? Could somebody perhaps recommend some specific one ?
Ideally, I would like it to be connected over serial port. Second best would be over USB.