Robust and Multilayer PowerPoint Watermarking for Source Tracing

Hybrid work with online circulation of office documents becomes the new norm while also giving rise to security risks like information leakage. Digital watermarking technology is an effective method for tracking multimedia data dissemination and ensuring authentication. In this article, a robust and blind multilayer PowerPoint document watermarking scheme based on slide format and zero-width characters is proposed. Based on the format characteristics of the slides, the title, subtitle, date, and page number placeholders of the slide masters and slide layouts are specifically selected as the embedding position of watermarks. Logistic chaotic sequences are used to displace the embedding positions, and uninvolved people without the key cannot extract watermarks. Multilayer embedding strategy and extensible capacity enables tracking of the source of document information leakage and clarifies the document dissemination chain. Related experiments show that, compared with previous work, our scheme provides high performance, good invisibility, and has wide application scenarios with strong robustness.