Earlier quoted context omitted.
Good compression should still be cryptographically distinguishable from true randomness right? Sure the various measures of entropy should be high, but I always just assumed that compression wouldn't pass almost any cryptographic randomness test.
not 'good' but maximum compression, yes.
Maximum compression should push ALL the 'work' to the compression alg, leaving essentially (no correlative bits) 'random' data to be decompressed.
Good compression, by definition, would leave small artifacts in the data, biasing it away from "true" randomness.
https://en.wikipedia.org/wiki/Kolmogorov_complexity
https://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theore...