3401 and highjacking

>>>>> "Stephen" == Stephen Kent
<kentbbn.com> writes:

    Stephen> What SRTP did was to add integrity and
confidentially to
    Stephen> RTP in a very careful, space-efficient
fashion. In so
    Stephen> doing, they reduced overhead well below what
one could
    Stephen> achieve via use of DTLS or ESP or AH.  This
is not a
    Stephen> practice I encourage for application in
general, because
    Stephen> the costs of custom designs of this sort are
very high,
    Stephen> and for most apps the bandwidth savings will
not justify
    Stephen> these costs. Also, as Joe noted, the
likelihood of
    Stephen> introducing security problems in such
designs (and in
    Stephen> implementations) is also very high.


The multimedia application also has a number of other
special
requirements.  I think that multimedia streams over cellular
networks
are one of the few cases I've seen where confidentiality
without
integrity may be reasonable.

Humans will know if an attacker significantly corrupts a
voice or
video stream.  However the cost of lost packets do to
corruption of a
MAC may be unacceptable given radio error rates.

--Sam

_______________________________________________

On Mon, Mar 13, 2006 at 02:08:15PM -0500, Sam Hartman wrote:
> The multimedia application also has a number of other
special
> requirements.  I think that multimedia streams over
cellular networks
> are one of the few cases I've seen where
confidentiality without
> integrity may be reasonable.
> 
> Humans will know if an attacker significantly corrupts
a voice or
> video stream.  However the cost of lost packets do to
corruption of a
> MAC may be unacceptable given radio error rates.

Although authentication can still help at least provide
feedback to the
user as to the quality of reception (100% vs. not 100% 
_______________________________________________