Say I own a digital copy of a copyrighted movie. Is it legal for me to encrypt it with say, AES, and share it to the Internet so anyone could download the encrypted copy?

It actually breaks down to these 4 situations:

  1. Is it legal if I don't share the decryption key to anyone?
  2. Is it legal if I share the decryption key privately to someone who also owns the same copy?
  3. Is it legal if I share the decryption key privately to someone who doesn't own the copy?
  4. Is it legal if I share the decryption key publicly online?

If in any of the above situations it is not legal, which party/parties is/are liable?

Edit: Additional question: How does the above 4 situations apply to the content that is not owned by you, say a video "illegally" downloaded from YouTube.

  • 2
    Part of the answer depend on the jurisdiction you are in. For instance, sharing copyrighted material privately is fine in some countries.
    – PMF
    Oct 8, 2022 at 7:41
  • I think we can limit discussion to the US?
    – yvbbrjdr
    Oct 8, 2022 at 7:51
  • Note that DVDs and Blu-rays are or were shipped encrypted content (remember DeCSS), and cloning an encrypted DVD is definitely considered copyright infringement.
    – pjc50
    Oct 11, 2022 at 10:27
  • @pjc50 In the case of a DVD, any legal DVD player has a decryption key, so an identical copy may be encrypted, but not as far as my DVD player is concerned. I can play it just the same as a DVD that I bought in a store. Don't know how this works with Blu-ray.
    – gnasher729
    Oct 11, 2022 at 15:07

1 Answer 1


An encrypted copy is still a copy. Making and distributing copies of a protected work without permission is infringement under US copyright law unless fair use or another exception to copyright applies.

  • Making a copy for the purpose of time-shifting, that is watching or listening at a more convenient time has been held to be fair use.
  • Making a copy as a backup to a lawfully owned physical medium in case of damage to or loss of the medium has been held to be fair use.
  • Making a purely personal copy (from a lawfully held copy) may be a fair use.
  • Making a copy (from a lawfully held copy) to share with a strictly limited group may be a fair use. If the group is a single household, it is fair use.

I don't know of other situations which are probably fair use and fit this question at all. But fair use is an intentionally flexible concept, so I cannot say that no other situation would be fair use.

  • 2
    For copying to share within a household, what is the basis that that is considered fair use? Is there a court case where that was decided?
    – Brandin
    Oct 11, 2022 at 6:45
  • @Brandin I think that three is a statutory provision for that, but I will have to check. I will update the answer when/if I have more precise info/. Oct 11, 2022 at 18:53
  • I wonder if uploading something encrypted, without decryption keys, would be copyright infringement. If I give a decryption key only to three friends.
    – gnasher729
    Oct 12, 2022 at 12:51

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