Privacy, security and public opinion

[Brian Gladman]

From: "Owen Lewis" <oml@eloka.demon.co.uk>
To: <ukcrypto@maillist.ox.ac.uk>
Sent: Tuesday, May 30, 2000 10:40 AM
Subject: Re: Privacy, security and public opinion

> ----- Original Message -----
> From: "Dave Bird" <dave@xemu.demon.co.uk>
> To: <ukcrypto@maillist.ox.ac.uk>
> Sent: 22 May 2000 20:31
> Subject: Re: Privacy, security and public opinion
> >  So far you haven't done much on this thread except be silly +
> >  irrelevant,  and I haven't intervened much except to point out your
> >  silliness +  irrelevance.
>
> Don't sell yourself short. You have also managed to demonstrate, yet
again,
> the vain use of 'ad hom' as a bluster to cover a total lack of substance.
> >
> >  Defensive and offensive are relative terms.  An anti-aircraft gun is
> >  basically defensive  in function,  to stop enemy aircraft attacking
> >  one of your own positions.  Placed on board a hostile frigate which
> >  has wandered up to Dover and started shelling ships in the harbour,
> >  the operation and every system in it serves an offensive purpose:
> >  including the AA gun which fends off attacks from British aircraft
> >  defending home territory.
>
> Thank you reiterating my point for me. The offensive or defensive
> colouration of cryptography is similarly entirely relatative, deriving
from
> the purpose to which it is applied and also, perhaps, is subjective to the
> viewpoint of an observer. There's really no more to be said.

I can now see why you believe that cryptography is neither offensive or
defensive. You appear to believe that the terms 'offensive' and 'defensive'
can only be applied to an overall activity (or system) and not to its
individual sub-components. Moreover you appear to be unwilling to accept
that design intent rather than end use can give a technology an offensive or
defensive character.

While a pure science will not generally be offensive or defensive, as soon
as it is applied for some specific (military) purpose the latter will very
often give the resulting technology an offensive or defensive character.

Hence materials science (neither offensive or defensive) can be used to
build castle walls which have a defensive purpose.  Likewise a shield is
defensive by design.  A user can abuse a shield by using it offensively but
this does not change the designer's intent to provide something that is
intended for defence.

Turning to cryptography, this is not a pure science but rather an applied
one in which mathematics (for example) is used for the specific purpose of
defending information.  I believe the design intent here is unambiguously
defensive whereas you believe that this purpose is neither offensive nor
defensive.  Offence is about being proactive and taking the initiative
whereas defence is essentially passive and reactive.  Cryptography does not
take the fight to the enemy, it sits passively waiting to repel any enemy
onslaught that might be mounted and this, in my view, gives it the
characteristscs of defence rather than offence.

You also appear to take the view that if an end system is used for offence
then every sub-component of this system is, by definition, offensive.  In
contrast I take the view that an offensive (defensive) system can contain
sub-components of the opposite character.  Hence if a tank is being used
offensively you then characterise its armour as offensive whereas I take the
view that its armour is a defensive sub-system designed to protect the
tank's occupants from attack.

Others can judge for themselves which line of thinking better fits their own
perceptions of reality.

     Brian