>...it may even be cryptographically signed ... In general, anything you are going to sign has to be in a simple enough format to make it so that the sender an

>...it may even be cryptographically signed ... In general, anything you are going to sign has to be in a simple enough format to make it so that the sender and the receiver(s) can actually determine what is signed. HTML should automatically be considered unsigned. It simply is not suitable for the purpose.