> The beauty of business cards and webpages. I have neither. But let's say that I did have a web page - what's to prevent the key from being reaped by the spam service industry? Given the immense volume of legitimate email that crosses the net every day, any solution to the spam problem has to scale. Yours doesn't. What you're proposing is basically a semi-P-K-no-I, where you've got a great big bootstrapping problem with the credentials. I really don't think the spam problem is one that can be solved cryptographically, anyway. Melinda