This isn't relevant to the question so I don't include it.

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I want to archive files and have these problems:

- The files are big and I therefore don't want data created in intermediate steps to a disk (and the data doesn't fit in the RAM, of course).
- I want to encrypt them but `tar` doesn't offer encryption.
- I don't want the file attributes to be lost but `7zip` doesn't care.
- I want to be able to access my files without looking anything up and just using standard software, so no weird stuff because according to Murphy's law, I will definitely not find the instructions of how to access my data once I want to do so.
- I want a checksum in case the medium I write the archive to gets corrupted and I'm not going to trust that medium to hold the data until it has been fully written as this would partly defeat the purpose of the checksum.