TAN OTP Authentication

I propose a module that provides some hooks that can be implemented by specific authentication mechanisms (e.g. TAN, OTP). Users with the appropriate permissions could add 'additional authentication mechanisms' to certain nodes (e.g. for editing or viewing), to certain forms (e.g. voting on certain (or all) polls), changing profile-fields, submitting new date, etc), or add some kind of 'anonymous user authentication' (e.g. allowing anonymous users to submit new content - but only when providing some kind of pre-generated OTP), or whatever else.