[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[freehaven-dev] Re: tractable DL paper

Some time ago I e-mailed this fellow asking about his "Delegation Logic." 
Here's the response I received; it may be of interest. Brian, are you 
interested in e-mailing him about what our trust module does? It may be
that there's some cute trick or two he knows about which would be


---------- Forwarded message ----------
Date: Sat, 8 Apr 2000 21:31:22 -0400 (EDT)
From: Ninghui Li <ninghui@cs.nyu.edu>
To: dmolnar@hcs.harvard.edu
Subject: Re: tractable DL paper (fwd)


The attached file is the paper to appear in Oakland conference.
I also got your email asking about implementation of DL.  I am very 
sorry for this very late reply.  I was completely buried with paper 
writing and implementing new version of DL the last couple of months.

The main feature of DL's delegation is integer and infinite 
delegation-depth and complex principal structures as delegatees.  
Many applications do not need all this expressive power; a somewhat
limited version should suffice.

You mentioned a project to build an Eternity service and said that you 
were trying to formulate policies about questions like "will I trust 
server X to store my file F for time T ?" and "is this request to do 
operation O on file F a good request?"  I would like to hear more about
your project.  Such queries can be easily formulated in DL or other Logic
Programming languages.  The more important issue is what kind of 
information is going to be used in making this decision and how to 
represent and reason with this information.  

I have an implementation of Delegation Logic that is written in XSB, 
a Prolog variant developed at SUNY - Stony Brook.  I've also experimented 
with a Interprolog, a Java-XSB interface program.  I don't know whether
a Prolog implementation is acceptable to your project.


---------- Forwarded message ----------
Date: Wed, 26 Jan 2000 03:07:22 -0500 (EST)
From: dmolnar <dmolnar@hcs.harvard.edu>
To: Joan Feigenbaum <jf@research.att.com>
Cc: ninghui@cs.nyu.edu
Subject: Re: tractable DL paper

Ninghui, Joan, 

Thank you very much for your response! I had been looking for 
access control models with explicit / formal treatments of delegation a
few months ago, but had not found anything really satisfactory. So I am
very happy to hear about your paper and look forward to reading it.

Thanks much, 
-David Molnar

On Sun, 16 Jan 2000, Joan Feigenbaum wrote:

> Hello, David.  This paper is about delegation of trust, for
> system-security purposes as well as business and other purposes.
> It is part of the PhD thesis work of my student Ninghui Li at
> NYU.  He is developing a logic-based "trust-management system,"
> for expressing security policies and credentials and for 
> determining whether requested actions comply with policies.
> Ninghui, Benjamin Grosof (at IBM), and I are currently putting together
> a conference version of this paper.  It will be posted on my web page as
> soon as it's finished; in the meantime, I am cc'ing this message to Ninghui
> so that he will know to send you a copy once it's in a stable state.
> Regards,
> Joan
> >From dmolnar@hcs.harvard.edu  Wed Jan 12 18:31:59 2000
> Return-Path: <dmolnar@hcs.harvard.edu>
> Received: from mail-blue.research.att.com (mail-blue.research.att.com [])
> 	by fry.research.att.com (980427.SGI.8.8.8/8.8.7) with ESMTP id SAA51540
> 	for <jf@fry.research.att.com>; Wed, 12 Jan 2000 18:31:59 -0500 (EST)
> Received: by mail-blue.research.att.com (Postfix)
> 	id 72B934CE1F; Wed, 12 Jan 2000 18:31:59 -0500 (EST)
> Delivered-To: jf@research.att.com
> Received: from hcs.harvard.edu (hcs.harvard.edu [])
> 	by mail-blue.research.att.com (Postfix) with ESMTP id 23B2D4CE13
> 	for <jf@research.att.com>; Wed, 12 Jan 2000 18:31:59 -0500 (EST)
> Received: from localhost (dmolnar@localhost) by hcs.harvard.edu (8.8.5/8.8.3) with ESMTP id SAA12001 for <jf@research.att.com>; Wed, 12 Jan 2000 18:31:58 -0500 (EST)
> Date: Wed, 12 Jan 2000 18:31:58 -0500 (EST)
> From: dmolnar <dmolnar@hcs.harvard.edu>
> To: jf@research.att.com
> Subject: Practical Delegation Logic paper available?
> Message-ID: <Pine.OSF.4.05.10001121829410.14635-100000@hcs.harvard.edu>
> MIME-Version: 1.0
> Content-Type: TEXT/PLAIN; charset=US-ASCII
> Hi, 
> I noticed that you have a paper on a "tractable and practical delegation
> logic" listed on your page. 
> Is this delegation in the sense of delegating computation to many
> not-particularly-trusted third parties over a network, or delegation in
> the system security sense? 
> Would it be possible to have a copy of the paper at some point? 
> Thanks much, 
> -David Molnar