If you want to download an HTML page to a user, have their browser display it, but not be able to read the HTML, then no, that is not possible. The browser needs to read the HTML to interpret and display it, so if it is encrypted, it kind of defeats the purpose.

The only way you could do something like that would be to develop your own custom display plug-in that could decrypt/display the page. Frankly, any decryption that takes place on the end-user's host is subject to reverse engineering anyway, so I would recommend you don't even bother.