[bwiggs]

You would still expect some amount of file structure, ex byte headers or something at the beginning/end of file. no?

[Crestwave]

That would be expected for encodings or container file formats. Straight-up encryption like AES produces results that are visually indistinguishable from random data.

[throwawaysoxjje]

I’d expect the greater length of the encrypted data (which should look random) vs the structured header/footer to rapidly push the Shannon entropy to the maximum

[wang_li]

No. Why would you? Encrypted data should look no different than random. The app figures out if it is the app's data after it attempts to decode it.