The Daily Hallucination

MOUNTAIN VIEW, Calif. — An invisible watermarking system developed to identify AI-generated images can hide 136 bits of information in a single 512-by-512 picture, according to a research paper now circulating among privacy advocates, who point out that this is enough to store a unique identifier for every person on Earth and still have 72 bits left over.

"People are focusing on the capacity," said a spokesperson for a company that develops such systems. "We would prefer they focus on the invisibility. It is very invisible. You will never see it. That is the part we are proud of."

The system's stated purpose is to let software determine whether an image was made by AI. Critics, including a widely shared essay that has renamed the technology "spymarks," note that an identifier which can say "this was generated" can, with the same bits, say "and by whom," and that the person who generated it is not asked.

"A normal watermark is a signature in the corner," said Beatrix Anandakrishnan-Moll, a researcher in media forensics. "This is a signature in every pixel, written in an ink that only the pen company can read, which it promises to use responsibly, and which it will explain in a future blog post."

A technical analysis of the capacity found that after a 64-bit database identifier, the remaining 72 bits are used for error correction, which engineers explained is there to ensure that the identifier survives cropping, compression, screenshots and filters.

"It is very robust," said the spokesperson. "You can put the photo through almost anything and it will still know it is yours. We think that is beautiful. Some people think it is a tracking device. Those people are also correct."

At press time, a user had taken a photograph of a printed photograph, and the watermark had come along anyway, like a relative.