Scientists develop 'ghost font' that only humans can read and leaves AI bots stunned
One computer scientist has developed an innovation that's left AI bots stunned and unable to decipher, making it a way for humans to communicate privately.
Scientist Eric Lu took to social media to share his new font, which is visible when moving through static.
In a post on X, formerly Twitter, Lu wrote: “I created a font called Ghost Font that only humans can read. Tested it in Fable and GPT 5.6 Sol Ultra and neither was able to decipher it correctly.”
On the website, it details how Ghost Font act as an ‘anti-AI’ font by writing the message using motion.
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It explains: “Using a combination of motion, video, noise, and decoys, it's a unique way to share a message with other real humans. I suppose technically, it's not a font in the traditional sense of a TTF font file. But, Ghost Font is an experiment of a way to graphically communicate in writing in a format that AI cannot easily understand. While it's not as legible as regular text, the letters are still immediately readable to a human eye, but even leading AI models can't decipher it easily.”
The videos generated using Lu’s font have been tested on AI models including the likes of Claude and ChatGPT but even the most recent AI agent models, which are able to code, ‘struggled to decode the moving message until prompted with the exact technique to look for’.
In fact, the AI bots found it so difficult that, after spending 19 minutes analysing the image, ChatGPT 5.5 Pro ‘hallucinated a message that doesn’t exist’.
Lu goes on to say: “There are certain implications for Ghost Font that I think would be interesting to continue to explore. For example, it would be interesting to incorporate Ghost Font into CAPTCHA systems, as most systems are easily solved by AI today. Using motion in a video would be a way to make it much more difficult for an automated bot to decipher but still relatively easy for a human to read.”
He adds: “A final lesson is that AI is certainly getting really good. While Ghost Font is hard for AI to read, it’s also pretty hard for humans to read! The gap continues to close. It will be interesting to see what the future holds when it comes to AI perception and multimodal models.”