[Cryptography] Of writing down passwords

[Bear]

On Sun, 2014-09-21 at 20:35 -0400, Harald Koch wrote:
> On 21 September 2014 07:54, Dave Horsfall <dave at horsfall.org> wrote:
>         
>           Choose a password that your[sic] can easily remember or
>         write it down.
>  
> It should be obvious by now that everything we think we know about
> passwords is wrong.
> 
> 
> These days I teach this heresy - people should choose really strong,
> hard-to-remember passwords, write them down, and stick them in their
> wallets. (obviously this doesn't apply to credit card PINs.) This is
> especially useful for rarely used passwords (like the WiFi router
> password).

Still, we're talking about the owner of a device accessing it to 
administer it.  

The owner of the device is distinguished from most network attackers
by having physical access to it. We even lampshade this by having a 
little hole you can poke a wire into to reset it to the default password
in most cases, so it's clear we're not securing the devices against 
anyone who has physical access.  

So if physical access allows admin privileges anyway, why don't we 
build these devices with a physical toggle switch?  Turn it ON, and 
with the password, you can get an admin interface.  Turn it OFF, 
and it won't respond with to any input with an admin interface no 
matter what.  Turn it ON and poke the wire into the hole, and you 
can reset it to the default password.  And you can see just by 
looking at the device which position the switch is in.

This is simple, easy to do, easy to check, costs no more than the 
toggle switch itself, and would stop 99.9% of all cases of 
unintended access to the admin interface cold, especially in the 
poorly-secured "home area network" markets that are the biggest 
security problem on the network today.  

				Bear