Army signals security & "Clansmen" series radios

[Owen Lewis]

----- Original Message -----
From: "David Hansen" <davidh@spidacom.co.uk>
To: <ukcrypto@maillist.ox.ac.uk>
Sent: 06 September 2000 14:30
Subject: Re: Army signals security & "Clansmen" series radios


> On 6 Sep 00, at 11:50, Owen Lewis wrote:
>
> > In sum, your view (which is a natural corollary to the popular
> > misconception of France's (non)participation in NATO) is entirely
> > mistaken.
>
> Not according to your earlier posting.

I'm sorry indeed if you feel I misled you but you were clearly mistaken
before I interjected. Therefore my posting has no bearing on your view.
>
> > One of the interesting points to ponder is whether - and if not why
> > not - the diplomats and military have not seized upon the invention of
> > public key ciphers, now 30 years old, as the single, simple and secure
> > solution to replace other more complex and expensive cipher systems.
>
> Because sound bite solutions are the realm of party politicians,
> journalists and others with a limited grasp of a subject.
>
> In any field of endeavour that I can think of (and which I have a
> reasonable knowledge of) "the single, simple and secure solution" is
> an illusion chased after by those with little knowledge. That's why
> PGP does not just use public key ciphers.

To take your points in reverse order:

    PGP does not 'just use PK ciphers' because, if it did, it would be too
slow by far for most purposes. The fact that it uses a block cipher at the
main engine, speeds things up greatly but, as implemented in PGP the last
time I looked at it,  does not add at all to whatever level of security the
PK encryptor of the block cipher key may give. Neither does the use of a
block cipher in PGP diminish the weakness of the 'web of trust' concept
which is central to PGP  when used as 'strong cryptography for the masses'.
But we surely don't need to rake over this again.

    With regard to 'sound bite solutions', do you suppose that any major
country uses a PK cipher for diplomatic and military purposes? If not, why
not? It's a reasonable question; is there a possible answer that you would
like to add to the soup?

>
>
>
>  David Hansen | davidh@spidacom.co.uk  | PGP email preferred
>  Edinburgh    | CI$ number 100024,3247 | key number F566DA0E
>
>