Unencrypting encrypted data that was downloaded

1. What is the issue? Please be detailed.
Downloaded encrypted data from ODK Cloud before our server went down, deleting a portion of the data. Files come out as dozens of files in scrambled text and as ####.dat.gz format. We have the keys.json file and the password, but running into some significant challenges in unencrypting the data

2. What steps can we take to reproduce this issue?
Download encrypted data with the keys.json file, and attempt to unencrypt the data using that file and password.

3. What have you tried to fix the issue?
Have tried to use unzipping apps, have tried unencrypting the data, but without the specific encryption methodology it seems impossible.

4. Upload any forms or screenshots you can share publicly below.

Usually users download their encrypted submissions via the dialog below. Is that the dialog you encountered or did you download the data some other way?

If you got the above dialog, when you hit Done, you should have received a my-form-id.zip file that, when unzipped, should give you CSVs and any media. Did you get a zip file for each group of submissions you downloaded?