There's a computerphile video (https://www.youtube.com/watch?v=XZJc1p6RE78 https://www.youtube.com/watch?v=XZJc1p6RE78) with Dr. Mark Pound explaining a paper b

There's a computerphile video (https://www.youtube.com/watch?v=XZJc1p6RE78 https://www.youtube.com/watch?v=XZJc1p6RE78) with Dr. Mark Pound explaining a paper by John Kirchenbauer, Jonas Geiping et al. (https://arxiv.org/abs/2301.10226 https://arxiv.org/abs/2301.10226) that described a method for watermarking LLM output like this. It's not directly stated anywhere in the Claude support article that this is what they're using, but the properties of the watermark described seem to point to this method.