The .DAT log files on the Mavic Air and Mavic 2 are encrypted. The Mavic Mini .DAT log files are probably encrypted but in a way different from the MA and M2. .DATs from the remaining DJI platforms are not encrypted and can be read by DatCon.
.DATs created by either the Go4 or the Fly app are not encrypted and can be read by DatCon. The .txt created by either the Go4 or the Fly app is encrypted, but not seriously encrypted allowing us to break it. IMHO, the .txt encryption scheme exists to make it possible to detect a counterfeit .txt.
As mentioned above the MM encryption is different than the MA an M2. It may not be an encryption scheme. I.e., just an encoding scheme which would allow it to be read. But, I'm guessing it's encrypted.
Thanks very clear exposition.
From what you say any encrypted version is so DJI can verify that a public readable file can't be doctored to show something that didn't happen.
Quite reasonable. Cynical hat disposed of. Many thanks.