This is a file compression program I wrote in JavaScript when I was 17 after 4 years of effort (I’m 21), and I improved it for 4 more years, which outputs to Base32768, rather than the Base2 of binary, and features AES256-CTR encryption too. Files don’t have to be binary. This program’s files have the .B3K extension. This program makes no external requests and can be ran offline.
Here is some documentation of the program’s format: http://justsolve.archiveteam.org/wiki/BWTC32Key
Also, it ended up on WikiData (essentially a subsidiary of Wikipedia): https://www.wikidata.org/wiki/Q105859280
Also, the program is FOSS. It’s an open standard.