Abstract: Secured binding system (1) for a document. The system comprises two strips (11, 13) each provided with an inner face (17, 21) and an outer face (19, 23). The first strip (11) comprises at least one tab (29, 29?) extending over its inner face (17) and arranged so as to be inserted into a perforation in the document, then into a corresponding perforation (31, 31?) made in the second strip (13). The tab is arranged to be folded down and attached to the outer face (23) of the second strip (13). The system (1) comprises irreversible assembly means arranged to allow a single attachment of the tab (29, 29?) to the outer face (23) and to mark said outer face (23) in the event of removal of the tab (29, 29?), and authentication means (41, 43, 48) of said binding system (1) integral with the document.