Zero-knowledge (ZK) circuits enable privacy-preserving computations and are central to many cryptographic protocols. Systems like Circom simplify ZK development by combining witness computation and circuit constraints in one program. However, even small errors can compromise security of ZK programs -- under-constrained circuits may accept invalid witnesses, while over-constrained ones may reject valid ones. Static analyzers are often imprecise with high false positives, and formal tools struggle with real-world circuit scale. Additionally, existing tools overlook several critical behaviors, such as intermediate computations and program aborts, and thus miss many vulnerabilities. Our theoretical contribution is the Trace-Constraint Consistency Test (TCCT), a foundational, language-independent formulation of ZK circuit bugs. TCCT provides a unified semantics that subsumes prior definitions and captures both under- and over-constrained vulnerabilities, exposing the full space of ZK bugs that elude prior tools. Our systems contribution is zkFuzz, a novel program mutation-based fuzzing framework for detecting TCCT violations. zkFuzz systematically mutates the computational logic of Zk programs guided by a novel fitness function, and injects carefully crafted inputs using tailored heuristics to expose bugs. We evaluated zkFuzz on 452 real-world ZK circuits written in Circom, a leading programming system for ZK development. zkFuzz successfully identified 85 bugs, including 59 zero-days-39 of which were confirmed by developers and \nfixed fixed, including bugs undetectable by prior works due to their fundamentally limited formulations, earning thousands of bug bounties. Our preliminary research on Noir, another emerging DSL for ZK circuit, also demonstrates the feasibility of zkFuzz to support multiple DSLs.

Vertical Federated Learning (VFL) has emerged as a collaborative training paradigm that allows participants with different features of the same group of users to accomplish cooperative training without exposing their raw data or model parameters. VFL has gained significant attention for its research potential and real-world applications in recent years, but still faces substantial challenges, such as in defending various kinds of data inference and backdoor attacks. Moreover, most of existing VFL projects are industry-facing and not easily used for keeping track of the current research progress. To address this need, we present an extensible and lightweight VFL framework VFLAIR (available at https://github.com/FLAIR-THU/VFLAIR), which supports VFL training with a variety of models, datasets and protocols, along with standardized modules for comprehensive evaluations of attacks and defense strategies. We also benchmark $11$ attacks and $8$ defenses performance under different communication and model partition settings and draw concrete insights and recommendations on the choice of defense strategies for different practical VFL deployment scenarios.

Federated Learning with Model Distillation (FedMD) is a nascent collaborative learning paradigm, where only output logits of public datasets are transmitted as distilled knowledge, instead of passing on private model parameters that are susceptible to gradient inversion attacks, a known privacy risk in federated learning. In this paper, we found that even though sharing output logits of public datasets is safer than directly sharing gradients, there still exists a sub-stantial risk of data exposure caused by carefully designed malicious attacks. Our study shows that a malicious server can inject a PLI (Paired-Logits Inversion) attack against FedMD and its variants by training an inversion neural network that exploits the confidence gap between the server and client models. Experiments on multiple facial recognition datasets validate that under FedMD-like schemes, by using paired server-client logits of public datasets only, the malicious server is able to reconstruct private images on all tested benchmarks with a high success rate.

This paper investigates the effect of precoding in multiple input multiple output (MIMO) transmission from the viewpoint of transmitter antenna configurations, i.e., space diversity (SD) or polarization diversity (PD), in field experiments using the Evolved UMTS Terrestrial Radio Access (E-UTRA) experimental system. The field experimental results show that there is no performance gap between with and without precoding irrespective of the antenna configuration in a non-line of sight (NLOS) environment when a common precoding vector is applied over the entire signal bandwidth of 18 MHz and the maximum likelihood detection with QR-decomposition and M-algorithm (QRM-MLD) based algorithm is applied at the receiver. In a high correlation channel as observed in a line of sight (LOS) environment, there is also no performance gap between with and without precoding. However, in the high received SINR region, the throughput performance of the precoding with the PD configuration is worse than that without precoding since decoding errors occurred in both codewords, which are mapped onto two different transmitters, due to a significantly high received power gap between vertically and horizontally-polarized antennas.

This paper investigates the effect of the antenna (polarization diversity (PD) or space diversity (SD)) configuration at evolved Node B and antenna angle of user equipment (UE) on the throughput performance of multiple input multiple output (MIMO) in Evolved UMTS Terrestrial Radio Access (E-UTRA) field experimental system. The results show that the throughput performance as a function of the measured signal-to-interference plus noise power ratio (SINR) per antenna for the PD configuration is degraded by approximately 1 dB and 3-6 dB in a 2times2 MIMO case for non-line of sight (NLOS) and line of sight (LOS) environments, respectively, and 1-2 dB in a 4times4 MIMO case for a NLOS environment, when the angle of the receiver antenna is 0 degrees due to variation in the average received power gap between vertically-polarized and horizontally-polarized waves. On the other hand, when the receiver antenna angles are 45 or 90 degrees, the throughput performance for the PD configuration is almost the same as those for the NLOS environment and is improved compared to those for the LOS environment, respectively, due to a smaller average received power gap and lower fading correlation. It is also shown that the cumulative distribution function (CDF) of the throughput performance when using the PD configuration is nearly identical to those for the 2times2 and 4times4 MIMO cases irrespective of the UE antenna angle for the NLOS environment. The CDF in this case is also better than those for the SD configuration when the UE antenna angle is 90 degrees for the NLOS environment and 45 and 90 degrees for the LOS environment.

This article presents an outline of information on the usability activities in Japan with a focus on the last 10 years. Although there were many activities in academia, substantial efforts were made in industry, and both activities coincided to form unique usability engineering in the country. Because of the language barrier that exists in many Japanese usability engineering professionals, just a few works have been presented at international conferences. This is the reason why the tried to summarize in English the usability engineering activity in Japan.

We developed a pointer in 3D virtual space, using an eye-tracking system as a sensor. The eye mark pointer is installed to a virtual environment system which provides stereoscopic vision with an immersive projection display. The circular-polarization stereoscopic vision enables us to use the eye-tracking system in the immersive projection display. The eye-tracking system obtains relative gaze directions with respect to the head, so the absolute position requires compensation of the user's head motion with a head tracker. We then compare the eye mark pointer with a joystick in an experiment with the virtual environment system. The experimental result indicates the pointing of the eye mark pointer is 9.8 times quicker than that of the joystick, and suggests that the eye mark pointer is available for pointing at the target in the virtual environment.