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        RFC 1949:

        Title:      Scalable Multicast Key Distribution
        Author:     A. Ballardie
        Date:       May 1996
        Mailbox:    A.Ballardie@cs.ucl.ac.uk
        Pages:      18
        Characters: 41,853
        Updates/Obsoletes:  none

        URL:        ftp://ds.internic.net/rfc/rfc1949.txt


The benefits of multicasting are becoming ever-more apparent, and its
use much more widespread. This is evident from the growth of the
MBONE. Providing security services for multicast, such as traffic
integrity, authentication, and confidentiality, is particularly
problematic since it requires securely distributing a group (session)
key to each of a group's receivers.  Traditionally, the key
distribution function has been assigned to a central network entity,
or Key Distribution Centre (KDC), but this method does not scale for
wide-area multicasting, where group members may be widely-distributed
across the internetwork, and a wide-area group may be densely
populated.  Even more problematic is the scalable distribution of
sender-specific keys. Sender-specific keys are required if data
traffic is to be authenticated on a per-sender basis.  This memo
provides a scalable solution to the multicast key distribution
problem.

This memo defines an Experimental Protocol for the Internet
community.  This memo does not specify an Internet standard of any
kind.  Discussion and suggestions for improvement are requested.
Distribution of this memo is unlimited.

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Joyce K. Reynolds
USC/Information Sciences Institute