[Feature Request] Compressed/Encrypted output to target volume

[JDB]

Hello,

This may have been considered before, but perhaps worth bringing up again:

Would it be feasable to introduce an option to compress and encrypt target files and directories without having to use BitLocker or VeraCrypt (etc)?

For example, pass all output files and directories through a pipe, such as Zip/UnZip using I/O redirection, or incorporate Zlib directly into FFS. One Zip file could be used to represent each subdirectory, provided that the size does not exceed OS limitations. A password could be used to encrypt each Zip file.

This would require accurate metadata to store information about each file, sort of like the "sidecar" concept commonly used to store the EXIF/XMP attributes of RAW camera images. If the target volume is NTFS, then an Alternate Data Stream on each Zip archive could be used to hold the metadata for each file in the archive. (I know... I hate ADS too, but it might serve a purpose here.) The drawback to metadata is that it would be publicly accessible, even though the file contents are encrypted.

The justification for this would be to write a secure backup to an external drive, which is compressed to reduce size, yet portable to any system by anyone without FFS who knows the password. For example, a last resort disaster-recovery.

This might be easier to implement if just writing only to the target, but comparisons, re-syncing, and restoring individual files back to the source volume would be a challenge. The metadata would have to be bulletproof, and a separate utility might be needed to rebuild the metadata if there is any corruption of the association between the metadata and the Zip archive it represents.

Thanks,
JDB