Sorry I can't attribute the quote properly; Microsloth Mail strikes again...
[modems that change speed in mid-transmission proposed as a defense against wiretap]
Aaron
This would probably thwart someone trying to tap the data stream in real time, assuming that the speed changes caught the snooper by surprise, but I don't think that real-time data traps are the real problem. Someone who went to the effort of listening in on your transmission would probably record the whole session on tape; then, they could map the speed changes and pick up all the data at their leisure later on. I would speculate that a really good DAT deck could record the modem session well enough to give your opponent all the time he needs to figure out the speed shifts and pick up the data. -Philippe