Can anyone identify this compression/encryption tool?

**Mexxi** · 9th August 2014, 02:54

I just stumbled over some strangely compressed Video DVD ISO files.
The files don't contain any recognizable ISO structure, but appear to be compressed or encrypted. Their header always starts with "@JZ". The files carry their native ISO-file ending.

Each ISO is accompanied by a file with an rqv-file ending. The file is no text file, yet contains vast portions of human readable text. It seems to be a file descriptor file for the iso and contains the content structure of the ISO, the volume name, but also external info such as reviews. The header of the file is "ReQuestVideo".

Despite the unique header and the file ending of the rqv-file google didn't spit out anything, not a single result, so I'm all the more curious. The fact that the ISO is still moderately compressible even with weak ZIP-compression leads me to believe that the file is rather encrypted and not compressed, but I'm no expert on the subject.

Does somebody have an idea which program produces such outputs? I appended an rqv-file and a 100kb-chunk of the corresponding iso.