title_body: Is there any way to remove DRM from DAISY ebooks?
upvoted_answer: I have no idea on how to solve the general problem of DRM
  removal. Depending on where you live, it may actually be very much
  against the law.
  
  Furthermore, as I said in a comment, DAISY books come in different
  formats, independently of DRM, depending on whether they contain
  speech, text to be speech synthesized or both. I think the most common
  standard is DAISY 2.02, which (from what I understand) contains only
  speech, but I am no expert on DAISY which I never heard of before.
  
  I would expect that the type of DRM used is dependent on the standard,
  and may also depend on the publisher, or on the brand of the
  reader. Thus there may be no universal answer to your question. 
  
  For a specific book, it may be useful to know the standard used, and
  probably the kind of reader, or the kind of DRM.
  
  Now, you tell in a comment, which you should (probably) integrate to
  your question to better focus it, that you are interested in the book
  at
  https://archive.org/download/asdrivenleaf00stei/asdrivenleaf00stei_daisy.zip
  
  I still do not know how to remove the DRM technically, and, if I knew,
  answering you could get me into significant trouble. The archive.org
  site is a wonderful site (I mean that), which by its very purpose is probably not too friendly to
  DRM, but there is nothing they can do when a book is still under
  copyright custody.
  
  To know more , I unzipped the file, which I hope you did too. This
  gives you a bunch of files, including a file README_encrypted.txt
  which says it uses a key from the National Library Service, and point
  to the files http://openlibrary.org/help/faq/accessing#what-is-daisy
  and https://nlsbard.loc.gov/ for more explanation.
  
  They explain that the program (for modern books, hence under
  copyright) is reserved to residents of the USA and
  American citizens living overseas. I am not quite sure how they do
  that legally, though they clearly enforce that with the DRM key.
  
  Some countries do have laws that make a copyright exception to the
  benefit of disabled people within the country. I am not sure whether
  that is the case in the USA, but it would be the simplest
  explanation. However it does not explain giving access to American
  citizens in other countries, since international treaties give the USA
  jurisdiction on copyright only within the USA.
  
  Now if your country of residence has a similar law (free access for
  disabled people) then it is possible that the National Library Service
  would accept to give you a key to be used from your country, since
  that would not raise any copyright infringement issue (though they might want to have an official agreement between countries). Maybe you
  can try to discuss that with the people at info@archive.org, or the people
  at NLS. And you shold check the copyright law in your own country
  regarding exceptions for disabled people.
  
  This is just my best understanding, and all the suggestions I can give to solve your problem, and I am not a lawyer.