Cryptoblog: A weblog somehow concealed or encrypted, so as to restrict those who have access. Unlike password based restrictions or ‘friends lists,’ cryptoblogs are intended to present an overt challenge to those wanting access, calling upon them to exercise cleverness in figuring out how.
Also, cryptoblogging: the act of writing a cryptoblog.
See also, weblog: A frequently updated web site consisting of personal observations, excerpts from other sources, etc., typically run by a single person, and usually with hyperlinks to other sites; an online journal or diary. (Source: OED)