Well, sloppy thinking breeds complexity -- what I dislike about standards commitees (IETF/IESG included) is that they always sink to the lowest common denominator of the design talent or competence of its participants. In fact, a method to encrypt small parcels of data efficiently is well-known for decades. It is called "stream cypher" (surprise). Besides LFSR-based and other stream cyphers, any block cypher can be used in this mode. Its application to RTP is trivial and straight-forward. Just leave sequence number in clear text, so that position in the stream is recoverable in case of packet loss. It also allows precomputation of the key stream, adding nearly zero latency/jitter to the actual packet processing. --vadim On Wed, 19 Feb 2003, David Luyer wrote:
...leaving a dream of RTP as true and presumably light-weight protocol...