Re: Use Cases for Encapsulation and Identification

[Marcus Brinkmann]

Hi,

> Since Marcus has agreed that we should focus on Encapsulation,
> Identification, and combinations of these, I will disregard the original
> wording of the challenge.

You are making a mistake by disregarding the requirement for
confinement.

My challenge is to find an application for encapsulation and
identification _in the presence of confinement_.  I have already
conceeded applications for encapsulation and identification that are
not confined, in particular system services and user-to-user
communication.

So, let's look at your examples.

At Mon, 01 May 2006 14:52:32 -0400,
"Jonathan S. Shapiro" <address@hidden> wrote:
> The best mechanism (indeed, the *only* mechanism that really works) for
> electronic money that I know about is described here:

I have not studied electronic money.  So, please bear with me if this
is an ignorant question.  I have to ask because the answer could save
both of us a lot of time.

My understanding is that e-money is implemented using public key
cryptography, and independent of any operating system platform.

What am I missing here?

> 2. Health Privacy, or Equivalently, Privacy of Personal Information
> 
> We wish to build a computer support system for a hospital. In this
> application, it is necessary that different types of users are given
> different levels of access according to their role and their
> professional relationships to different patients.

This example is not confined, so it is already disqualified.

However, to play along: The computer that runs this application will
in all likelihood not be a general- or even multiple-purpose computer.
(To use it for more than one purpose could already constitute a
violation of the regulation, because it increases the risk of a
compromise).

Ownership (in the sense I am talking about) will be completely within
the hands of the responsible administrator of the hospital, and users
will only be able to access it through a fixed system-configured
interface.  Because there is only a fixed configuration, it is easy to
fulfill the requirements you stated.  In fact, they could be fulfilled
on MS-DOS.

If this does not look recognizable to you, you will have to clarify
the example.

Thanks,
Marcus