Apparatuses, methods, systems, and program products are disclosed for watermark security. An apparatus includes a watermark module configured to generate a digital watermark to be presented as part of a graphical interface based on data presented on the graphical interface. A digital watermark verifies an authenticity of data to be presented in a graphical interface. An apparatus includes a presentation module configured to embed the digital watermark into the graphical interface prior to the data being presented in the graphical interface such that the digital watermark is graphically imperceptible to a user, dynamically update the digital watermark during runtime in response to detecting a change in the at least a portion of the data that is encoded into the digital watermark, and re-embed the digital watermark into the graphical interface in response to the digital watermark being updated.