How To Verify the Public Key

How Secure Is It?

A miscreant would have to do the following to fool you into trusting another public key for me:

Of course, (s)he would have to this without you and me noticing when we exchange emails. Message signatures would start failing and encrypted information would fail to decrypt properly.

So, while all is possible it is extremely unlikely that someone would be able to submit a false public key for me. And if they succeeded, what do I have they might steal? :-)