[anonsec] 3401 and highjacking

[Sam Hartman]

>>>>> "Stephen" == Stephen Kent <kent at bbn.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