Piracy without punishing readers: the trace watermark
Heavy locks make honest readers pay for a few copiers. The ZI² approach keeps reading free of friction and makes a leaked copy traceable instead.
ZI² Books · 2026-09-23 · עודכן 2026-10-09
בקצרה: Licensed editions in the ZI² reader carry an invisible zero-width watermark derived from the license in every paragraph, append a citation with the license tag to copied text, cap copies at 1,200 characters, block drag-out and printing, and are resealed per buyer with the license written inside the book. Honest readers notice none of it; a leak names its source.
Every lock on a book is a tax on the people who paid for it. Readers who cannot copy a sentence for an essay, print a page for a class or open a file without an app are the ones who bought the book. The copier bypasses the lock in an afternoon.
We took the other road.
What a licensed copy carries
Inside the file: the license code, a masked licensee and the date, written in when the copy was sealed for its buyer. In the rendered text: a pattern of zero-width characters derived from the license, placed at the start of every paragraph, invisible to the eye and resilient to partial copies. On copy: a citation line with the book, author, chapter and license tag. Copies cap at twelve hundred characters, drag-out is blocked, and licensed editions do not print.
What a reader notices
Nothing. The text reads, scrolls, searches and speaks the same. Quotes come out with a proper citation, which many readers prefer.
What the press gets
A leaked file names its buyer twice, in the book and in the text. The audit chain shows which account opened and downloaded which copy, from which address. That is enough to act on, and it costs the reader nothing.
The honest limits
Once unlocked, text can be photographed or retyped. No reader on earth prevents that, and we do not pretend to. We make the leak traceable and keep the reading pleasant.
שאלות
Can I still copy a quote?
Yes, up to twelve hundred characters at a time, with a citation appended.
Why no printing?
A printed licensed edition is a copy without a watermark. Samples print; licensed editions read on any screen instead.
Does the watermark change the words?
No. The characters it uses have no width and no sound; search, read aloud and screen readers skip them.