In recent years, DeepFake technologies have seen widespread adoption in various domains, including entertainment and film production. However, they have also been maliciously employed for disseminating false information and engaging in video fraud. Existing detection methods often experience significant performance degradation when confronted with unknown forgeries or exhibit limitations when dealing with low-quality images. To address this challenge, we introduce Diff-ID , a novel approach designed to elucidate and quantify the identity loss induced by facial manipulations. When assessing the authenticity of an image, Diff-ID leverages a genuine image of the same individual as a reference and processes two images jointly. It aligns the reference image and the test image into the same identity-insensitive attribute feature space using a face-swapping generator. This alignment allows us to observe the identity disparities between the two images through the differences in the aligned generation pairs. Subsequently, we have developed a custom metric designed to quantify the identity loss relative to the reference image in the test image. This metric effectively distinguishes forgery images from the real ones. Extensive experiments have demonstrated the exceptional performance of our approach. It achieves a high level of detection accuracy on DeepFake images and showcases state-of-the-art generalization capabilities when confronted with previously unknown forgery methods. Moreover, it exhibits robustness even in the presence of image distortions.

Virtualization technology enables multiple virtual machines (VMs) to share a single physical server. Commercial servers increasingly use the nonuniform memory access (NUMA) architecture due to its scalable memory performance. However, multiple VMs running on a NUMA physical server will cause performance overheads such as remote memory access latency and shared microarchitectural resource contention, which makes the VM performance less efficient and stable. These performance overheads are mainly caused by memory traffic from data-intensive workloads. In this paper, we propose a traffic-aware VM optimization (TAVO) scheme on NUMA systems. Based on the performance monitoring of the data traffic and CPU/memory resource usages in the system, TAVO addresses VM memory access locality and shared resource contention problems via automatic VM initial placement and NUMA-aware VM online scheduling. Our experimental results show that TAVO improves VM performance in terms of benchmark runtime by up to 22.6% compared with the default KVM CFS scheduler. TAVO also achieves a much stable performance with benchmark's average runtime variation under 3%.

Zero-knowledge proof (ZKP) is a cryptographic primitive that enables one party to prove the validity of a statement to other parties without disclosing any secret information. With its widespread adoption in applications such as blockchain and verifiable machine learning, the demand for generating zero-knowledge proofs has increased dramatically. In recent years, considerable efforts have been directed toward developing GPU-accelerated systems for proof generation. However, these previous systems only explored efficiently generating a single proof by reducing latency rather than batch generation to provide high throughput. We propose a fully pipelined GPU-accelerated system for batch generation of zero-knowledge proofs. Our system has three features to improve throughput. First, we design a pipelined approach that enables each GPU thread to continuously execute its designated proof generation task without being idle. Second, our system supports recent efficient ZKP protocols with their computational modules: sum-check protocol, Merkle tree, and linear-time encoder. We customize these modules to fit our pipelined execution. Third, we adopt a dynamic loading method for the data required for proof generation, reducing the required device memory. Moreover, multi-stream technology enables the overlap of data transfers and GPU computations, reducing overhead caused by data exchanges between host and device memory. We implement our system and evaluate it on various GPU cards. The results show that our system achieves more than 259.5× higher throughput compared to state-of-the-art GPU-accelerated systems. Moreover, we deploy our system in the verifiable machine learning application, where our system generates 9.52 proofs per second, successfully achieving sub-second proof generation for the first time in this field.

Visual retrieval aims to search for the most relevant visual items, e.g., images and videos, from a candidate gallery with a given query item. Accuracy and efficiency are two competing objectives in retrieval tasks. Instead of crafting a new method pursuing further improvement on accuracy, in this paper we propose a multi-teacher distillation framework Whiten-MTD, which is able to transfer knowledge from off-the-shelf pre-trained retrieval models to a lightweight student model for efficient visual retrieval. Furthermore, we discover that the similarities obtained by different retrieval models are diversified and incommensurable, which makes it challenging to jointly distill knowledge from multiple models. Therefore, we propose to whiten the output of teacher models before fusion, which enables effective multi-teacher distillation for retrieval models. Whiten-MTD is conceptually simple and practically effective. Extensive experiments on two landmark image retrieval datasets and one video retrieval dataset demonstrate the effectiveness of our proposed method, and its good balance of retrieval performance and efficiency. Our source code is released at https://github.com/Maryeon/whiten_mtd.

One intriguing property of deep neural networks (DNNs) is their vulnerability to adversarial examples -- those maliciously crafted inputs that deceive target DNNs. While a plethora of defenses have been proposed to mitigate the threats of adversarial examples, they are often penetrated or circumvented by even stronger attacks. To end the constant arms race between attackers and defenders, significant efforts have been devoted to providing certifiable robustness bounds for DNNs, which ensures that for a given input its vicinity does not admit any adversarial instances. Yet, most prior works focus on the case of symmetric vicinities (e.g., a hyperrectangle centered at a given input), while ignoring the inherent heterogeneity of perturbation direction (e.g., the input is more vulnerable along a particular perturbation direction). To bridge the gap, in this paper, we propose the concept of asymmetric robustness to account for the inherent heterogeneity of perturbation directions, in addition to the magnitude, and present Amoeba, an efficient certification framework for asymmetric robustness. Through extensive empirical evaluation on state-of-the-art DNNs and benchmark datasets, we show that compared with its symmetric counterpart, the asymmetric robustness bound of a given input describes its local geometric properties in a more precise manner.