ScreenGuard: A Screen-targeted Watermarking Scheme Against Arbitrary Screenshot

Screenshot, which is a common tool in office work, has become a significant threat to organizations like companies and research institutions. Malicious users can easily leak sensitive information like business secrets and research data by taking a screenshot and spreading onto the Internet. While existing watermarking schemes serve as useful tools for leakage tracing, they fall short in the scenario of arbitrary screenshot. Most current methods are file-targeted, focusing on embedding watermark for a single file of one type at a time, making it hard to handle arbitrary content on screen. To address the issues above and better satisfy the need of the scenario, we propose ScreenGuard, a novel watermarking scheme targeted for the screen itself to protect arbitrary screen content shown on it. Unlike previous watermarking schemes, ScreenGuard does not modify the content itself. Instead, we generate a transparent mask template based on the watermark, tile it to the size of the screen to form a complete transparent mask, and overlay this mask onto the screen. This ensures that any screenshots taken will contain our watermark. We then train a locator and a decoder to extract watermarks from suspected leaked screenshots to trace leaks to their source. We summarized five properties that needs to be satisfied in the scenario of arbitrary screenshot (Generalizable, Unseeable, Adaptable, Robust, Dynamic) and evaluate our method on these criteria. Extensive experiments demonstrate that ScreenGuard meets these five properties effectively, showcasing its superiority and broad practical applications.