On Wednesday 10 September 2008 15:58:03 Kevin Neff wrote:
quoted text
> Hi,
>
> Some secure protocols like SSH send encrypted keystrokes
> as they're typed.  By doing timing analysis you can figure
> out which keys the user probably typed (keys that are
> physically close together on a keyboard can be typed
> faster).  A careful analysis can reveal the length of
> passwords and probably some of password itself.

This is nearly complete bullshit.  For any individual, learning
their characteristics could give rise to being able to know a
great deal about what they are doing, but hardly for the 
general case.

I know people who type blindingly fast.  I'm a mutant hunt
'n pecker, but I can go 50wpm+ when on a good keyboard and
awake, and far slower then conditions aren't good.  I also have
a problem with my right hand which makes for typing problems
at times.

How about people with severe physical problems?  I know a C4
quadrapledgic who types slowly, very slowly.  Depending on how
he feels, his speed varies by probably a factor of 4 or so.

Such a system could learn for an individual if you know things
about them.  But what about a Chord keyboard?  Dvorak?(sp)

If you want to worry, think about the sounds a keyboard makes.
Get an old IBM "buckling spring" keyboard (original PC and AT)
and listen to the sounds it makes.  That is something you
could probably decode with decent accuracy.

--STeve Andre'