L2/01-276



Re: Request to eliminate irregular sequences

From: W3C i18n committee
Date: 2001-07-20




   The W3C I18N WG applauds the restrictions imposed, for security
   reasons, in TUS 3.1, on the interpretation of UTF-8 non-shortest form
   BMP characters.

   We urge the Unicode Consortium to impose the same restrictions, for
   the same reasons, on UTF-8 non-shortest form characters outside the
   BMP.  In other words, "irregular code unit sequences" in UTF-8 should
   become "illegal code unit sequences".

   Owing to the inclusion, in TUS 3.1, of many characters outside of the
   BMP, this has become very topical.  Any ambiguity in the
   interpretation of UTF-8 has the potential to allow serious security
   breaches.