There are at least 4 patents involved, extensible file system, name hash lookup, transactional fat, contiguous file allocation. If you look at overcertified'a r

There are at least 4 patents involved, extensible file system, name hash lookup, transactional fat, contiguous file allocation. If you look at overcertified'a recent slideshare presentations on exFAT, including the recent HTCIA 2014 exFAT presentation, the patent numbers are listed on the ending reference slides.