Subject: [MSEC] Re: applications and motivation for mcast and group security

From: Roger Khazan <[email-masked]>
Date: Thu, 17 Mar 2005 15:03:03 -0500

A month ago I posted a message about motivation and applications for
group security. My original message is included at the bottom.

I am still very interested in this topic and would appreciate people
responding to my message.

So far, I received only two responses. Paul Gilbert and Cesc
Santasusana told me about the following applications, respectively:

1. Financial traders, which work together, form groups and supply and
receive trade information in these groups. In "large financials you
often see thousands of sources (traders) and hundreds of groups (split
into servers publishing market data
and traders sending)." Currently, this operation is supported by an
application from Reuters/Tibco that delivers market data to traders
and supports these groups. The application uses IP multicast with
best-effort reliability guarantees. Presently there is "no form of
security whatsoever for this multicast app."

So, this is a good application for group security. It seems that
having a central KDS would work here, but the protocols would need to
be stateless. Does this make sense? What are the security requirements
here?

2. I am still learning the specifics of this one, but it is about
supporting decentralized communication in military on-the-move
environments. For example, there is a need to support secure voice
conferencing among small groups of people. It is reasonable to assume
that initializations (e.g., distribution of keying material) are
handled by a centralized manager, but "daily operations must be able
to work without access to the central service."

The environment, scale, and requirements of this application are very
different from the first one. It seems that a *non-group* solution
would work well here: Use a fresh symmetric key for each voice
conference. Tell participants about this key by encrypting the key
with each participant's public key. Of course everyone's keys are
certified by some recognized authority. Instead of using public keys
all the time, we can also establish some long-term symmetric keys.
Does this make sense? Maybe it makes sense for groups of upto certain
size, but not for larger groups? Can we expect such larger groups in
this application?

--
Everyone would agree that research in group and multicast security, as
any other research, has to be driven by concrete motivation and
applications. The information about these is not widely-available or
is lacking. Let's pull our collective knowledge together and make a
strong case for this research area.

Looking forward to hearing your thoughts. Thank you. 

Roger Khazan
MIT Lincoln Laboratory

--------------------------------------------------------------------------------
[MSEC] applications and motivation for mcast and group security
Roger Khazan rkhazan at gmail.com 
Fri Feb 18 12:51:47 EST 2005 

I've been reading a lot about multicast and group security and I am
having hard time finding information about specific applications and
motivation, especially for decentralized solutions. One application
that comes to mind is group chat and shared collaborative workspace.
But there must be others...

I am wondering if people could share with me their thoughts and
knowledge about *specific* applications that require multicast
security and group security. Also, which specific applications require
(or can benefit from) *decentralized* key agreement solutions? Which
ones assume *centralized* solutions? I am looking for both
single-sender and multi-sender applications. Don't limit yourself to
collaborative applications; maybe there are some involving sensors or
multicast tree management, or some military applications? I am looking
for specific descriptions, not just general areas.

Are there systems *deployed in the world* today that utilize multicast
and group security?  Which ones? Which schemes do they use?

Are there examples in the past where we did not have group security in
place, but we wish we did? I'd like someone to make a compelling case
why all this stuff is necessary. If you work on designing group
security schemes, which big problem are you fixing?

Which prototype systems have been implemented and are available for
download and/or purchase?

Once I get responses from individual contributors, I will compile this
information and either send it to the list or provide it to the
individual contributors. Or, you can post your responses to the list.

Thank you,

Roger Khazan
MIT Lincoln Laboratory
_______________________________________________
msec mailing list
[email-masked]
http://six.pairlist.net/mailman/listinfo/msec

---

From: Mark Baugher <[email-masked]>
Date: Thu, 17 Mar 2005 13:27:09 -0800

Roger
   There is some work that is product-related that won't be discussed on  
this list before the products are announced.  There are some  
opportunities in group and multicast applications, but IP multicast is  
not widely deployed and has been much slower in its adoption than some  
of us expected eight or ten years ago.  The real-world deployments that  
I am aware of are largely satellite applications run by military and  
government agencies rather than commercial.  But practically speaking,  
any multicast application is a potential multicast security  
application.  And there are point-to-point applications that involve  
groups, which may also need group security.  A multi-point  
teleconference, for example, might benefit from a group security model  
rather than a point-to-point model even if there is a centralized  
control unit with point-to-point connections with the participants.

Mark