Any good symmetric encryption algorithm produces data that looks random. You can't tell whether it's just noise or encrypted data.
I'd expect a sane judge to treat cases like these as circumstantial evidence — e.g. the police thinks that random data is really encrypted data, but has no proof. From what I know, it is difficult (though not impossible) to land in jail based on circumstantial evidence.
I guess if you use encryption tools that add unencrypted metadata headers (as in "this is a file encrypted using AES-256 in CBC mode"), then the evidence is stronger.
Not quite what you're talking about, but there was recently a couple of posts by the 'binwalk' author about differentiating encrypted vs compressed data (presumed header-less):
I'd expect a sane judge to treat cases like these as circumstantial evidence — e.g. the police thinks that random data is really encrypted data, but has no proof. From what I know, it is difficult (though not impossible) to land in jail based on circumstantial evidence.
I guess if you use encryption tools that add unencrypted metadata headers (as in "this is a file encrypted using AES-256 in CBC mode"), then the evidence is stronger.