System and method for preventing gradient-based watermark removal from outputs of deep image generation models

A method for protecting a watermark embedded in an image output generated by a deep generation model, comprising:

• receiving, by an input interface module, input data comprising image files, text prompts, structured queries, or combinations thereof;
• normalizing, by the input interface module, the input data to produce normalized input data;
• applying, by an image generation module, a deep generation model to the normalized input data to generate a model-generated image;
• embedding, by a watermark embedding module, a non-visible ownership watermark into the model-generated image using a predefined watermark pattern to produce a watermarked image;
• receiving, by a decoder API module, a query image comprising the watermarked image or a derived version thereof;
• extracting, by a decoder submodule of the decoder API module, a watermark representation from the query image using a trained decoder network;
• and
• applying, by a decoder gradient shield submodule of the decoder API module, controlled perturbations to outputs of the decoder submodule under detection of adversarial query behavior, wherein the controlled perturbations modify the outputs of the decoder submodule in a manner that alters gradient direction or magnitude without degrading perceptual watermark quality.

A system for secure verification and protection of watermarked images exposed via a decoder interface, comprising:

• a decoder API module comprising:
• a decoder submodule configured to receive a query image and extract a watermark representation using a trained decoder network;
• and
• a decoder gradient shield submodule configured to apply controlled perturbations to outputs of the decoder submodule under detection of adversarial query behavior;
• and
• a gradient monitoring module configured to observe query inputs and decoder outputs over time, identify characteristics indicative of model extraction attempts, and signal activation of the decoder gradient shield submodule based on detection outcomes.