I actually wrote a library to do stego with LLM outputs last year and it turned out to be an almost exact implementation of the Anthropic watermark algo.
Repo here https://github.com/sutt/innocuous. It works with last year's llama.cpp. Check out the "Use Cases" and "How it works" sections in the readme if you're interested.
Repo here https://github.com/sutt/innocuous. It works with last year's llama.cpp. Check out the "Use Cases" and "How it works" sections in the readme if you're interested.