Re: [Phys-L] real-world physics : electronic privacy requires physics, not just algorithms

[Bernard Cleyet <bernardcleyet@redshift.com>]

On 2013, Sep 29, , at 18:22, John Denker <jsd@av8n.com> wrote:

> That's where physics comes in.  The laws of physics guarantee
> that any electrical resistor will always produce a certain
> amount of thermal noise, i.e. Johnson noise.  This is a
> guaranteed lower bound on the amount of noise.  You measure
> the temperature and the resistance and the bandwidth, and
> then you can calculate a reliable lower bound.
>
>  Please do not tell me about radioactivity.  Guess what?
>  I've already thought of that.  As a source of randomness,
>  it is in no way better and in many ways worse than Johnson
>  noise.


I have an MPT module which created noise to block enemy RADAR.  I presume at that time (WW II) it was less difficult than an amp. and a grid resistor.  

bc wonders if JD is thinking of dead time as a limitation of radioactivity as a noise source.