With current technology, default encryption massively slows down the web. This is Dan Bernstein's key research topic (I believe he's currently working on "High Speed Cryptography", his book, but that's in support of both his DARPA grant and his mission statement, which is "default encryption for everything"). That's a <i>cryptographer</i>, inventing and defending entire new algorithms, because that's what he believes is necessary to achieve default encryption.<p>In the meantime, what we really need to do is get rid of the stigma about SSL, which credibly solves the problems we're talking about on this thread.