Here's a hint
CRYPTOGRAPHY IS THE OPPOSITE OF DATA COMPRESSION

Data Compression tires to take disorder and find repeated or hidden patterns. So if you use a Sorting Algorithm on a uncompressed data stream, you get better compression.

Cryptography tries to take predictable plaintext or predictable encoded data files (with subsets of image file formats, video and audio fornats) turn turn that input stream into unrecognizable simulations of randomness.

Cryptography uses pseudorandom data shufflers (the opposite of Sorting Algorithms) or bit shifters or XOR overlays to add random-appearing features into the data stream.

But the thing Compression & Encryption have in common is LOSSLESS REVERSIBILITY.

But you say, JPEG and other image formats are LOSSY, trading bit accuracy for file size reduction. Aha, now you get it... stochastic encryption in image files gets fucked up by lossy file formats. But there are LOSSY ENCRYPTION formats too, such as using bit masks on microfilm to break one encoded data image into 4 or 6 overlays. You can do the same with audio encrypted by a XOR noise companion tape, good enough for human ears, hard to decode for computers.

Ironically, many simple data compression formats can be used to detect encrypted data.