Claude Fable 5.1 hides messages in images using height code

According to The Rundown AI citing Bryan Chan, researchers had Claude Fable 5.1 encode 50 secret messages in images via object heights and it was decoded in 39 cases by a fresh Fable session, while OpenAI GPT 6 Astra recovered 44. Researchers tested Claude Fable 5.1 by having it embed 50 short secret messages written in 15 languages into images the model generated itself, according to Bryan Chan on X reported by The Rundown AI. The model primarily encoded messages by varying the height of elements such as buildings, stars, and grass blades, applying this method in 33 of the 50 cases, and added contextual clues like a Kremlin tower for Cyrillic scripts when needed.

First reported by Blockchain News. This page is a short excerpt; the full text is theirs.