In the longer term, anonymous communication is in danger of being used only by fringe groups if it falls too much behind the non-anonymous kind in terms of latency and bandwidth (and cost, I guess). Maybe ONLY drug dealers, nuclear terrorists, etc., will use anonymous remailers when full sensory virtual interaction is the must popular way for most people to communicate and remailers are still the only choice for the anonymity-conscious.

My initial reaction to "Anonymous video conferencing" was "That's when you wear black ski masks and use voice scramblers and call from video payphones", i.e. not very useful. ("Subcomandata Marcos here...") On the other hand, Wei Dai's followup message about puts a different spin on it. It's a real problem, if not now, then maybe in 5-10 years. I realize that those of us in the Phone Company who have predicted universal Picturephone in the past have been over-optimistic :-), but the video compression people and the faster-chip people keep bringing us closer to having good-quality low-bandwidth video, and ISDN and fast modems are bringing available loop-end bandwidth up to the point that reasonably-priced circuits can carry it. (Long-haul raw bits have been cheap enough for a while; it's the distribution and switching technology that have a lot of the cost, and providing cheap high-bandwidth circuits makes it hard to make money on voice calls.) The approaches to anonymous video conferencing will depend a bit on whether the technology takes off on the nets or the phone system, if those two are still different by then. It's easier to obscure the origins of a call on the nets, where users own large parts, than it is on the phone system, where the Phone Companies own and operate most of it; the latter environment would require Phone Remailers, such as PBXs you call into on T1 lines and get shuffled out on other circuits - it's hard to get adequate mixing except in rather large environments.... Recircuiting on the nets will be left as an excercise to the reader. I suspect the harder parts of the job may be doing the faces and voices right - anonymous voice conference bridges are ok if the participants mostly don't know each other, but they're less useful if people know each other and cops with computerized voiceprint equipment may be eavesdropping (not common now, though computers and models of the human voice are improving; I suppose voice disguisers may improve from the kid's-toy quality to something better if there's a market, or if computers with full-duplex soundcards become more common.) Faces are harder, and they're not really a crypto problem - how do you fake them well? It's not too hard to do a "quayletool" quality solution that generates moving lips in front of a static picture, even timed with an audio feed, but that won't play too well in the business world, and having the camera pointing at your calendar or home page is only semi-useful. If video-calling evolves on the nets, there'll be a lot more need for speed-matching services, and it may be that computer-enhanced video receiving for high-bandwidth users will fund the technology development for face-simulation? If so, maybe you can use it to start with fake stills instead of real ones? Bill