[Cryptography] Any Electrical Engineers here who know about noise filtering?

[Ron Garret]

On Jan 2, 2016, at 6:50 AM, Henry Baker <hbaker1 at pipeline.com> wrote:

> Here's my problem:
> 
> I'm trying to characterize a 1x pad.
> 
> A 1x pad *adds* (modulo, but that shouldn't matter)

But it does matter.  That’s what makes it secure.

> uniformly distributed "noise" (the "key") to the
> "message" signal.
> 
> Classical filtering theory says that given a
> noise spectrum, one can compute an optimal
> filter to remove as much noise from the signal
> as possible.

Yes.  In a linear system.  XOR is non-linear.

rg