Re: Wireless home LAN - WiFi vs Bluetooth?
On 29.07.19 14:44, Joe wrote:
> On Mon, 29 Jul 2019 09:34:25 -0400
> Dan Ritter <dsr@randomstring.org> wrote:
> >
> > In a single-family house, Powerline is about as secure as wired
> > ethernet: you need to come in and plug something in to spy on
> > it.
>
> Most people won't have RF blocking filters at their house electricity
> inlet, so there may be some leakage to the next house that's on the
> same phase.
Several of those clamp-on ferrite noise suppression cores, of a size to
fill a partly closed fist, would do some good without requiring wiring
alteration.
> I can get a reliable connection on the end of about 100ft of house and
> extension cable, so I wouldn't be surprised to be able to find a signal
> in another house.
And ethernet cable is twisted pair, minimising radiation. Power wiring
is just parallel conductors, so a sniffer has more signal to pick up.
Additionally, transmitted power levels in a Powerline network would
likely be higher than on a clean ethernet cable, due to the intermittent
electrical noise found on power circuits, due to switching loads,
motors, etc. (It's either that or retransmit corrupted packets.)
The analog designers in an R&D lab I worked in about 40 years ago spent
their lunch hours on a powerline intercom. Pushing a good clean signal
through the noise was a challenge.
> Presumably, when we speak of security here, we're not talking about
> accidental reception, wi-fi WEP would be sufficient to prevent this,
> but a deliberate attempt to break in. We could assume that someone
> trying to get into a power-line link would be able to amplify the
> signals involved.
The street wiring would act as an extension of the antenna provided by
the house wiring, and with much larger loop area between conductors,
radiate much better. Acting against that is masking RF noise from
everything else in the street, requiring either selectivity or at least
a capacitive connection in the street or the comfort of a neighbour's
house.
But even if you have a wireless keyboard, the your passwords are out there
several times per day, I figure.
Erik
Reply to: