On Tue, 2004-03-30 at 01:17, Wayne Wilson wrote:
> Implications for medical messaging:
> 
> HL7 has long taken the view that they would not build in security 
> mechanisms as long as existing message layer standards were in place. 
>   S/MIME was early looked at as the 'way'.    Now, it seems the faith 
> is being put into XML digital signature http://www.w3.org/Signature/ .
> 
> Both of these approaches build on the PKIX work.  So does the US 
> Government.  I am certain this is because of the top down nature of 
> the architecture, i.e. the notion of creating a 'root' trust 
> authority, from which all other trust stems. It's natural for large 
> agencies, NGO or GO to want to posistion themselves as the 'trusted' 
> ones.
> 
> My personal opinion is that the business world and the world of 
> individual privacy runs counter to that model and creates a 
> resistance.  But even if that is not a big issue, the technical inter 
> operability and the complexity of the standards themselves are so 
> great that nothing really practical is on the near term horizon.

The situation in Australia might be instructive. Several years ago the
Health Insurance Commission (HIC) tried to establish their own PKI for
the health professionals. HIC is a govt body which administers Medicare,
which is our universal health insurance scheme (and which has slowly
been whittled away by conservative govts, but there is an election this
year and that might stop the rot...). Alas, HIC made multiple mistakes:
a) the scheme was clearly focused on helping them reduce operational
costs by encouraging doctors to submit patient claims electronically,
instead of on paper, and HIC refused to endorse the use of their PKI for
any other purpose - a huge blunder, since the cost savings to doctors of
submitting electronically were negligible, or negative, whereas teh cost
savings of other uses of a PKI to doctors are potentially large - but
such uses were not endorsed; b) they chose a typical top-down X.509 PKI
dictated by the govt security agency, and designed for public servants
in govt depts, without realising that the main users would be general
practitioners who are independent small business people, not govt
employees; c) the scheme they chose relied on proprietary hardware
dongles, which were fiddly, and had restricted Windows-only proprietary
APIs (initially, now a Java API); d) they insisted (and still do) on
generating the private signing and encryption keys themselves, and then
distributing these private keys to the users by courier - yet the end
users  are expected to sign a document confirming that the signing keys
are as good as their written signature - this practice, of refusing to
allow self-generation of private keys, completely undermines the basis
of PKI and people have been wary of the system as a result; e) they
failed to establish an easy-to-use (eg LDAP-enabled) directory of public
keys, and the key revocation list facilty initially (still does?) rely
on users manually updating their keyrings - which is never going to
happen; f) the end user agreement initially ran to over 100 pages of
closely typed text (now shortened); g) the certificate authority they
use, originally an Australian security company, has changed hands twice,
and is now a US multinational. Not surprisingly, given all these
reasons, the uptake of the system has been small, despite all the
software and hardware being given away for free (for now at least),
although it is beginning to pick up now in some areas, but 4 years and
many tens of millions of dollars down the track. Last year they started
to offer cash incentives to medical software companies to support the
scheme. See http://www.hesa.com.au/ if you are interested in more
details.

> No one has found the 'right' combination of automation and scalability 
> yet.  Neither PKIX scaling downwards nor PGP scaling upwards have 
> found the magic ease of use to build a community of trust which will 
> drive forward this technology.

In contrast to the HIC PKI system, several local groups of GPs have just
been getting on with establishing local secure email networks using GPG,
at minimal cost. David Guest, who subscribes to this list, operates one
such network - David, can you give us a thumb-nail sketch of the
Northern Rivers system? Another example is operated by the Top End
(Northern Territory) Division of General Practice, who have built a nice
LDAP directory service which holds GPG public keys - see
https://www.tedgp.asn.au/servicedir/loginform.php 

So I think it can be done using GPG - but some degree of social cohesion
and a good organiser is required. Whether GPG-style Webs-of-Trust (WoT)
can scale up remains to be seen, but I see no reason why they can't,
with local WoT bridged to others by designated "bridge-builders".
However, in most settings, the majority (90% or more) of health care
communication occurs between local parties, who are all likely to be
part of a single WoT. If a GPG system is a bit less convenient for the
rarer "long-distance" electronic communication, then that is not a
disaster - but even that remains to be seen. I am impressed who well GPG
works across the Internet with correspondents anyway - but you do need
GPG + social organisation + policies to make it work. But not policies
which drag on for hundreds of pages. The back of an envelope should
suffice to list them. Is that correct, David?
-- 

Tim C

PGP/GnuPG Key 1024D/EAF993D0 available from keyservers everywhere
or at http://members.optushome.com.au/tchur/pubkey.asc
Key fingerprint = 8C22 BF76 33BA B3B5 1D5B  EB37 7891 46A9 EAF9 93D0


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