Re: Preliminary results of using GPS to look for clock skew

[Rick Jones <rick.jones2@hp.com>]

On 09/22/2011 10:34 AM, Dave Taht wrote:
> On Thu, Sep 22, 2011 at 10:15 AM, Rick Jones<rick.jones2@hp.com>  wrote:
>>
>>>
>>> One thing that surprised me of late is
>>> http://www.bufferbloat.net/issues/271
>>>
>>> while not related, surprises are the last thing we need as regards to
>>> time.
>>>
>>
>> The decision to stop letting networking contribute to entropy goes back a
>> few years actually :)
>
> I wasn't paying attention then.
>
>> In another context, also where running-out of entropy was a problem, someone
>> mentioned there are RNGs on USB keys that can be used to provide
>> randomness/entropy/whatnot.  The one mentioned in that discussion was the
>> "Entropy Key" from these folks: http://www.entropykey.co.uk/
>
> While I would like RNGs to be on-chip, the lack of randomness in a system
> that supposedly does a lot of WPA encryption does concern me.
>
> https://dev.openwrt.org/ticket/9631
>
> Secondly, routers at least have multiple interfaces to get randomness from
> which would be hard to spoof all at the same time.
>
> and wireless routers have more noise sources and interfaces...
>
> so while I find the decision to eliminate networking as a source of randomness
> makes some sense in a device with only one interface, I find it indefensible to
> have nearly no entropy pool at all as a result for devices with
> multiple interfaces.

I don't necessarily disagree, but there were a number of reasons given, 
many of which I believe are/were independent of the number of interfaces 
in the host.  I believe at least some of it can be found at 
http://lkml.indiana.edu/hypermail/linux/kernel/0805.3/0370.html  though 
I don't think it has the thread all the way back to its beginning.

rick