[cap-talk] Simple Cooperative File Sharing (SCoopFS), the "F" is silent

James A. Donald jamesd at echeque.com
Mon Mar 9 18:34:03 EDT 2009

Karp, Alan H wrote:
 > We've been working on a project in usable security for
 > the past couple of years and finally got around to
 > writing a tech report.  Comments appreciated.
 > http://www.hpl.hp.com/techreports/2009/HPL-2009-53.html

The system relies on email to provide human memorable,
globally unique, designations.  These are used for the
initial contact to set up secure Zooko type webkey
designations.  Thereafter, everything is secure, thanks
to a buddy list based on Zooko's triangle, and email
designations no longer necessary or used.

But translation between email and Zooko, setting up
buddies, is both a security burden on users, and a
source of security weakness.

Further, though in an email based world we need to start
from email, we really want to have in sight a world with
no more email.

If people are already on the system, they could get new
buddies from multiple recipients on a message, but we
really want a way to add new buddies from an out of band
communication.  At present this is done by communicating
an email address out of band.

Two elements are missing:

1.  a way to refer to entities by their Zooko id, so
that petnames in messages  between buddies appear as
hyperlinks with anchor text expressed as the local

2.  a way to perform initial communications with non
buddies, so that one can add buddies to the system based
on out of band communication using humanly manageable
bandwidth independent of the email name system.

A Zooko/webkey based system must start in a world where
email and therefore email designations are pervasive,
but should aim for a world in which email is no more.

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