A version of your suggested solution is currently in use in Estonia [1], although it is not really used to encrypt e-mails. I guess it's one of the virtues of

A version of your suggested solution is currently in use in Estonia [1], although it is not really used to encrypt e-mails. I guess it's one of the virtues of having a population a tad smaller than 1.5 million. [1]http://en.wikipedia.org/wiki/Estonian_ID_card http://en.wikipedia.org/wiki/Estonian_ID_card