Sounds like Magic Wormhole (https://magic-wormhole.io/). The readme acknowledges Warner at the end.
Key differences seem to be resumable transfers and proxy support.
Another is a single binary, whereas MW is in Python, but there’s now https://github.com/magic-wormhole/magic-wormhole.rs
I appreciate that the project acknowledges its inspiration. I wish it were more common for projects to provide detailed comparisons with similar ones for people trying to choose.
I’ve found croc to be more reliable than MW in across different network architectures — croc has worked in places where MW has not. I’m not sure why.