Watermarking
Every rewrite carries a keyed watermark that no reader can see, and it leaves the quality and the voice unchanged. With the key, a school, publisher or platform can check whether Pessoa wrote a text, even when it reads as fully human.
- 98%
- of writers identified from four of their texts.
- 1 in a million
- is the false-alarm rate the test is held to.
- 0
- real human writers flagged, across 600 writers in 4,000 groups.
Detection Accuracy
One text is often enough. Several texts from the same writer make the answer near certain, because the evidence adds up across them.
How It Works
- Selective Marking
Pessoa only marks words where a writer could have picked something else. The facts, names and wording that carry your meaning are left alone, so the mark costs nothing in quality or voice.
- Keyed Verification
The mark is tied to a secret key. Without it the text is ordinary text. With it, a statistical test says how likely it is that Pessoa wrote it.
- Secondary Detection
For text whose mark has been stripped, a separate detector of our own gives a second opinion.
Applications
Writers keep a voice that's theirs. Everyone else gets a way to check.
A way to see whether Pessoa wrote a submission, even when it reads as human.
Check text at scale with the key, without asking writers to change how they work.
EU rules require AI-generated text to carry a machine-readable mark. The watermark is built with that in mind.