[LINK] Schneier on Storm Worm

steve jenkin sjenkin at canb.auug.org.au
Mon Oct 8 11:06:58 AEST 2007


Craig Sanders wrote on 8/10/07 6:49 AM:
> On Sun, Oct 07, 2007 at 07:57:37PM +0200, Kim Holburn wrote:
>> I don't think we really disagree on much.  I just think that a lot
>>  of work needs to be done so that computers do all the really hard
>>  part of the work on security.
>
> i think we disagree on a pretty fundamental point from which all the
> rest follows. you think that a complicated, infinitely tool like a
> computer CAN be made as simple as a toaster or a car.  I don't.

That's simple to prove:
    Ashby's Law of Requisite Variety:
        "the capacity of a regulator cannot exceed its capacity as a
channel of communication."
   Or more informally, a model of a system has to have sufficient
internal states (variety) to adequately 'control' a system [or
model/describe its behaviour].

<http://www.panarchy.org/ashby/variety.1956.html>

For a Man+Machine combined system, a total amount of 'variety' is
required to control/address all possible states.
It either has to come from the person or the machine.

Computer programs can handle a lot internally (high 'variety') and have
a simple (low 'variety') interface,
or they can have little internal 'variety' and push almost everything
onto the user...

Answering your assertion:
    "An infinitely complicated tool ... can be made as simple as a
toaster or car"
    Yes - the *User Interface* can be made simple *if and only if* the
program picks up the slack.
    [But see the Einstein quote below]

Your example of the car is a very good illustration:
    The first cars had all the engine & mechanical controls exposed -
        timing (advance), mixture, throttle, choke, ...
    Even in the 1970's cars were made with a manual 'choke'.
    These days, the engine management computer handles everything -
        including retarding the spark to avoid damage from low-octane
petrol 'pre-detonations' (pinging).

    => The *car* has become more complex to present a simpler User
Interface.
         The total variety of the whole system has not changed...

> in fact, i think that that ideal of simplification is a big part of
> the problem.

Einstein: "Everything should be made as simple as possible, but no simpler."

There is a difference (essential) "simplicity" and "simple minded".
Good models remove the inessentials...

<snip>

>
> craig
>


-- 
Steve Jenkin, Info Tech, Systems and Design Specialist.
0412 786 915 (+61 412 786 915)
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