Lukovnikov, Denis
Towards A Correct Usage of Cryptography in Semantic Watermarks for Diffusion Models
Thietke, Jonas, Müller, Andreas, Lukovnikov, Denis, Fischer, Asja, Quiring, Erwin
Semantic watermarking methods enable the direct integration of watermarks into the generation process of latent diffusion models by only modifying the initial latent noise. One line of approaches building on Gaussian Shading relies on cryptographic primitives to steer the sampling process of the latent noise. However, we identify several issues in the usage of cryptographic techniques in Gaussian Shading, particularly in its proof of lossless performance and key management, causing ambiguity in follow-up works, too. In this work, we therefore revisit the cryptographic primitives for semantic watermarking. We introduce a novel, general proof of lossless performance based on IND\$-CPA security for semantic watermarks. We then discuss the configuration of the cryptographic primitives in semantic watermarks with respect to security, efficiency, and generation quality.
Black-Box Forgery Attacks on Semantic Watermarks for Diffusion Models
Müller, Andreas, Lukovnikov, Denis, Thietke, Jonas, Fischer, Asja, Quiring, Erwin
Integrating watermarking into the generation process of latent diffusion models (LDMs) simplifies detection and attribution of generated content. Semantic watermarks, such as Tree-Rings and Gaussian Shading, represent a novel class of watermarking techniques that are easy to implement and highly robust against various perturbations. However, our work demonstrates a fundamental security vulnerability of semantic watermarks. We show that attackers can leverage unrelated models, even with different latent spaces and architectures (UNet vs DiT), to perform powerful and realistic forgery attacks. Specifically, we design two watermark forgery attacks. The first imprints a targeted watermark into real images by manipulating the latent representation of an arbitrary image in an unrelated LDM to get closer to the latent representation of a watermarked image. We also show that this technique can be used for watermark removal. The second attack generates new images with the target watermark by inverting a watermarked image and re-generating it with an arbitrary prompt. Both attacks just need a single reference image with the target watermark. Overall, our findings question the applicability of semantic watermarks by revealing that attackers can easily forge or remove these watermarks under realistic conditions.
Set-Membership Inference Attacks using Data Watermarking
Laszkiewicz, Mike, Lukovnikov, Denis, Lederer, Johannes, Fischer, Asja
In this work, we propose a set-membership inference attack for generative models using deep image watermarking techniques. In particular, we demonstrate how conditional sampling from a generative model can reveal the watermark that was injected into parts of the training data. Our empirical results demonstrate that the proposed watermarking technique is a principled approach for detecting the non-consensual use of image data in training generative models.
Improving the Long-Range Performance of Gated Graph Neural Networks
Lukovnikov, Denis, Lehmann, Jens, Fischer, Asja
Graph Neural Networks (GNN) form a class of neural network architectures specifically designed to work with graphstructured data. In our work, we focus on multi-relational graphs, where edges are labeled with different edge types. While different GNN variants have been proposed in recent literature, to the best of our knowledge, their ability to capture long-term dependencies in graph data has not been thoroughly investigated. Due to their local aggregation nature, many layers of a GNN must be used to capture long-range patterns (i.e., at least K GNN layers are needed to incorporate any information from a node that is K hops away in the graph). However, GNNs suffer from decreasing performance when the number of layers is increased.
Introduction to Neural Network based Approaches for Question Answering over Knowledge Graphs
Chakraborty, Nilesh, Lukovnikov, Denis, Maheshwari, Gaurav, Trivedi, Priyansh, Lehmann, Jens, Fischer, Asja
Question answering has emerged as an intuitive way of querying structured data sources, and has attracted significant advancements over the years. In this article, we provide an overview over these recent advancements, focusing on neural network based question answering systems over knowledge graphs. We introduce readers to the challenges in the tasks, current paradigms of approaches, discuss notable advancements, and outline the emerging trends in the field. Through this article, we aim to provide newcomers to the field with a suitable entry point, and ease their process of making informed decisions while creating their own QA system.
Translating Natural Language to SQL using Pointer-Generator Networks and How Decoding Order Matters
Lukovnikov, Denis, Chakraborty, Nilesh, Lehmann, Jens, Fischer, Asja
Translating natural language to SQL queries for table-based question answering is a challenging problem and has received significant attention from the research community. In this work, we extend a pointer-generator and investigate the order-matters problem in semantic parsing for SQL. Even though our model is a straightforward extension of a general-purpose pointer-generator, it outperforms early works for WikiSQL and remains competitive to concurrently introduced, more complex models. Moreover, we provide a deeper investigation of the potential order-matters problem that could arise due to having multiple correct decoding paths, and investigate the use of REINFORCE as well as a dynamic oracle in this context.
Learning to Rank Query Graphs for Complex Question Answering over Knowledge Graphs
Maheshwari, Gaurav, Trivedi, Priyansh, Lukovnikov, Denis, Chakraborty, Nilesh, Fischer, Asja, Lehmann, Jens
In this paper, we conduct an empirical investigation of neural query graph ranking approaches for the task of complex question answering over knowledge graphs. We experiment with six different ranking models and propose a novel self-attention based slot matching model which exploits the inherent structure of query graphs, our logical form of choice. Our proposed model generally outperforms the other models on two QA datasets over the DBpedia knowledge graph, evaluated in different settings. In addition, we show that transfer learning from the larger of those QA datasets to the smaller dataset yields substantial improvements, effectively offsetting the general lack of training data.
Incorporating Literals into Knowledge Graph Embeddings
Kristiadi, Agustinus, Khan, Mohammad Asif, Lukovnikov, Denis, Lehmann, Jens, Fischer, Asja
Knowledge graphs, on top of entities and their relationships, contain another important element: literals. Literals encode interesting properties (e.g. the height) of entities that are not captured by links between entities alone. Most of the existing work on embedding (or latent feature) based knowledge graph modeling focuses mainly on the relations between entities. In this work, we study the effect of incorporating literal information into existing knowledge graph models. Our approach, which we name LiteralE, is an extension that can be plugged into existing latent feature methods. LiteralE merges entity embeddings with their literal information using a learnable, parametrized function, such as a simple linear or nonlinear transformation, or a multilayer neural network. We extend several popular embedding models using LiteralE and evaluate the performance on the task of link prediction. Despite its simplicity, LiteralE proves to be an effective way to incorporate literal information into existing embedding based models, improving their performance on different standard datasets, which we augmented with their literals and provide as testbed for further research.