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Friday 17 April

Cryptography and Security

A Protocol-Agnostic Backscatter-Based Security Layer for Ultra-Low-Power SWIPT IoT Networks

This paper presents a lightweight, protocol-agnostic security enhancement for Simultaneous Wireless Information and Power Transfer (SWIPT) in Internet of Things (IoT) applications. Building on a backscatter-based identification mechanism, the proposed approach introduces a secure, energy-efficient layer that operates independently of communication protocols and with minimal hardware modification. A rectifier-driven backscattering scheme embedded in battery-free sensing nodes enables authentication without activating conventional RF transceivers, thereby reducing power consumption while ensuring secure device identification. To assess robustness, replay attacks are emulated on standard LoRaWAN Activation By Personalization (ABP) encryption, highlighting vulnerabilities and demonstrating the relevance of the proposed solution. The approach is experimentally validated in a real Wireless Sensor Network (WSN) using LoRaWAN-compatible, battery-free sensing nodes equipped with compact, low-profile antennas, confirming both practicality and scalability for space-constrained IoT deployments. Results show that the method achieves secure identification, reliable energy harvesting, and data transmission with negligible impact on node autonomy. The proposed approach offers a practical, energy-efficient, and scalable security framework for SWIPT-enabled IoT systems, strengthening device authentication without altering existing communication protocols or compromising power autonomy.
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All authors Taki Eddine Djidjekh, Alexandru Takacs, Gaël Loubet, Lamoussa Sanogo, Daniela Dragomirescu

Cryptography and Security · Cross-listed from cs.CV

Beyond Text Prompts: Precise Concept Erasure through Text-Image Collaboration

Text-to-image generative models have achieved impressive fidelity and diversity, but can inadvertently produce unsafe or undesirable content due to implicit biases embedded in large-scale training datasets. Existing concept erasure methods, whether text-only or image-assisted, face trade-offs: textual approaches often fail to fully suppress concepts, while naive image-guided methods risk over-erasing unrelated content. We propose TICoE, a text-image Collaborative Erasing framework that achieves precise and faithful concept removal through a continuous convex concept manifold and hierarchical visual representation learning. TICoE precisely removes target concepts while preserving unrelated semantic and visual content. To objectively assess the quality of erasure, we further introduce a fidelity-oriented evaluation strategy that measures post-erasure usability. Experiments on multiple benchmarks show that TICoE surpasses prior methods in concept removal precision and content fidelity, enabling safer, more controllable text-to-image generation. Our code is available at https://github.com/OpenAscent-L/TICoE.git
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All authors Jun Li, Lizhi Xiong, Ziqiang Li, Weiwei Jiang, Zhangjie Fu, Yong Li, Guo-Sen Xie

Cryptography and Security

Secure Authentication in Wireless IoT: Hamming Code Assisted SRAM PUF as Device Fingerprint

Static Random Access Memory (SRAM) Physically Unclonable Functions (PUFs) make use of intrinsic manufacturing variations in memory cells to derive device-unique responses. Employing such hardware-rooted fingerprints for authentication, this work demonstrates a threshold-based authentication proof of concept for constrained Industrial Internet of Things (IIoT) devices. The proposed scheme can reliably cap the the post-authentication bit error rate (BER) below 1 %. Inherent SRAM PUF unreliability is addressed by a resource-efficient combination of Hamming code (HC) Error Correction (EC) and Temporal Majority Voting (TMV). Increasing HC redundancy or TMV count significantly reduces the BER, albeit with diminishing returns and increasingly prohibitive computational overhead. Furthermore, this work quantifies the threshold gap between strict reliability and security constraints. This gap is reframed as a design budget which enables the resource-aware calibration of the acceptance threshold, PUF response length, and stabilization technique, without violating designed-for error limits. Larger responses make reliability optimizations increasingly obsolete. This comparative analysis establishes a comprehensive design space for PUF EC, guiding future implementations in balancing EC quality against resource constraints such as computational demand, power consumption, and implementation complexity.
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Cryptography and Security

PoSME: Proof of Sequential Memory Execution via Latency-Bound Pointer Chasing with Causal Hash Binding

We introduce PoSME (Proof of Sequential Memory Execution), a cryptographic primitive that enforces sustained sequential computation via latency-bound pointer chasing over a mutable arena. Each step reads data-dependent addresses, writes a block whose value and causal hash are mutually dependent (symbiotic binding), and chains the result into a global transcript. This yields three properties: (1) strict linear sequential memory-step enforcement, (2) high time-memory trade-off resistance (a tenfold penalty at a write density of 4, with a formal space-time lower bound that scales quadratically with the number of steps), and (3) a tight ASIC advantage bound by DRAM random-access latency rather than bandwidth. Benchmarks across 17 CPU platforms and 4 GPU architectures demonstrate that hash computation is under 3.5 percent of step cost and GPU hardware is 14 to 19 times slower than a consumer CPU. POSME requires no trusted setup and provides a foundation for verifiable delay, authorship attestation, and Sybil resistance.
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Cryptography and Security

Privacy-Preserving LLMs Routing

Large language model (LLM) routing has emerged as a critical strategy to balance model performance and cost-efficiency by dynamically selecting services from various model providers. However, LLM routing adds an intermediate layer between users and LLMs, creating new privacy risks to user data. These privacy risks have not been systematically studied. Although cryptographic techniques such as Secure Multi-Party Computation (MPC) enable privacy-preserving computation, their protocol design and implementation remain under-explored, and naïve implementations typically incur prohibitive computational overhead. To address this, we propose a privacy-preserving LLM routing framework (PPRoute). PPRoute includes multiple strategies to speed up encoder inference and nearest neighbor search under the MPC and maintain the quality of LLM routing. First, PPRoute uses MPC-friendly operations to boost the encoder inference. Second, PPRoute uses a multiple-step model training algorithm to maintain routing quality despite the constraints of the encrypted domain. Third, PPRoute proposes an unsorted Top-k algorithm with $O(1)$ communication complexity for secure sorting in model search, significantly reducing communication latency. Across different datasets, PPRoute achieves the performance of plaintext counterparts, while achieving approximately a 20$\times$ speedup over naïve MPC implementations.
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All authors Xidong Wu, Yukuan Zhang, Yuqiong Ji, Reza Shirkavand, Qian Lou, Shangqian Gao

Cryptography and Security · Cross-listed from cs.CV

NeuroLip: An Event-driven Spatiotemporal Learning Framework for Cross-Scene Lip-Motion-based Visual Speaker Recognition

Visual speaker recognition based on lip motion offers a silent, hands-free, and behavior-driven biometric solution that remains effective even when acoustic cues are unavailable. Compared to traditional methods that rely heavily on appearance-dependent representations, lip motion encodes subject-specific behavioral dynamics driven by consistent articulation patterns and muscle coordination, offering inherent stability across environmental changes. However, capturing these robust, fine-grained dynamics is challenging for conventional frame-based cameras due to motion blur and low dynamic range. To exploit the intrinsic stability of lip motion and address these sensing limitations, we propose NeuroLip, an event-based framework that captures fine-grained lip dynamics under a strict yet practical cross-scene protocol: training is performed under a single controlled condition, while recognition must generalize to unseen viewing and lighting conditions. NeuroLip features a 1) Temporal-aware Voxel Encoding module with adaptive event weighting, 2) Structure-aware Spatial Enhancer that amplifies discriminative behavioral patterns by suppressing noise while preserving vertically structured motion information, and 3) Polarity Consistency Regularization mechanism to retain motion-direction cues encoded in event polarities. To facilitate systematic evaluation, we introduce DVSpeaker, a comprehensive event-based lip-motion dataset comprising 50 subjects recorded under four distinct viewpoint and illumination scenarios. Extensive experiments demonstrate that NeuroLip achieves near-perfect matched-scene accuracy and robust cross-scene generalization, attaining over 71% accuracy on unseen viewpoints and nearly 76% under low-light conditions, outperforming representative existing methods by at least 8.54%. The dataset and code are publicly available at https://github.com/JiuZeongit/NeuroLip.
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All authors Junguang Yao, Wenye Liu, Stjepan Picek, Yue Zheng

Cryptography and Security

Into the Gray Zone: Domain Contexts Can Blur LLM Safety Boundaries

A central goal of LLM alignment is to balance helpfulness with harmlessness, yet these objectives conflict when the same knowledge serves both legitimate and malicious purposes. This tension is amplified by context-sensitive alignment: we observe that domain-specific contexts (e.g., chemistry) selectively relax defenses for domain-relevant harmful knowledge, while safety-research contexts (e.g., jailbreak studies) trigger broader relaxation spanning all harm categories. To systematically exploit this vulnerability, we propose Jargon, a framework combining safety-research contexts with multi-turn adversarial interactions that achieves attack success rates exceeding 93% across seven frontier models, including GPT-5.2, Claude-4.5, and Gemini-3, substantially outperforming existing methods. Activation space analysis reveals that Jargon queries occupy an intermediate region between benign and harmful inputs, a gray zone where refusal decisions become unreliable. To mitigate this vulnerability, we design a policy-guided safeguard that steers models toward helpful yet harmless responses, and internalize this capability through alignment fine-tuning, reducing attack success rates while preserving helpfulness.
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All authors Ki Sen Hung, Xi Yang, Chang Liu, Haoran Li, Kejiang Chen, Changxuan Fan, Tsun On Kwok, Weiming Zhang, Xiaomeng Li, Yangqiu Song

Cryptography and Security

DEMUX: Boundary-Aware Multi-Scale Traffic Demixing for Multi-Tab Website Fingerprinting

Website fingerprinting (WF) attacks infer the websites visited by users from encrypted traffic in anonymous networks such as Tor. Existing deep learning methods achieve high accuracy under the single-tab assumption but degrade substantially when users open multiple tabs concurrently, producing interleaved traffic that transforms WF into an implicit demixing problem. We identify three structural requirements for effective multi-tab demixing, namely signal integrity at segment boundaries, multi-scale local modeling, and relative temporal association of dispersed fragments, and show that no prior method satisfies all three simultaneously. We propose DEMUX, a designed framework that addresses these requirements through three tightly coupled components. A Boundary Preserving Aggregation Module employs overlapping window partitioning with joint packet-level and burst-level feature extraction. A Multi-Scale Parallel CNN captures heterogeneous temporal patterns via parallel branches. A two-stage Transformer encoder with Rotary Positional Embedding enables robust cross-window fragment association. The Boundary Preserving Aggregation Module additionally serves as a plug-and-play preprocessor that consistently improves existing baselines without architectural modification. Extensive experiments across closed-world, open-world, defense-augmented, dynamic-tab, and cross-configuration settings demonstrate that DEMUX achieves state-of-the-art performance. In the challenging closed-world 5-tab setting, DEMUX attains a P@5 of 0.943 and MAP@5 of 0.961, outperforming the strongest baseline by 9.2 and 6.2 percentage points respectively, confirming its strong robustness in complex multi-tab demixing scenarios.
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All authors Yali Yuan, Yaosheng Liu, Qianqi Niu, Guang Cheng

Cryptography and Security

DPDSyn: Improving Differentially Private Dataset Synthesis for Model Training by Downstream Task Guidance

How to synthesize a dataset while achieving differential privacy for AI model training is a meaningful but challenging problem. To address this problem, state-of-the-art methods first select original private dataset's multiple low-dimensional distributions that have the potential to approximate the distribution of original private dataset with high precision, and then synthesize a dataset obeying all selected low-dimensional distributions as the synthetic dataset. However, it is difficult to select suitable low-dimensional distributions, which in turn degrades the data utility of resulting synthetic dataset. To improve differentially private dataset synthesis, we propose to train a differentially private AI model for downstream tasks on the original private dataset and utilize the trained model to synthesize datasets. In particular, on the one hand, the AI model satisfies differential privacy so no matter how to use the model does not disclose private information of original private dataset. On the other hand, the AI model is trained to complete the downstream task so the AI model preserves critical information for completing downstream tasks. We utilize the AI model to synthesize datasets to achieve the goal of improving data utility while preserving privacy. Empirical evaluations on four benchmark datasets demonstrate that our proposed DPDSyn consistently outperforms eight state-of-the-art baselines with a maximum improvement of 2.40x in accuracy and 333.73x in synthesis efficiency. Further experiments also validate that DPDSyn has strong scalability across varying data scales.
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All authors Mingxuan Jia, Wen Huang, Weixin Zhao, Xingyi Wang, Jian Peng, Zhishuo Zhang

Cryptography and Security

Half-Moon Cookie: Private, Similarity-Based Blocklisting with TOCTOU-Attack Resilience

Blocklisting is a common technique for preventing the use of known malicious content. However, conventional blocklisting infrastructures require either the blocklist to be public or clients to reveal their queries to the blocklist server. We introduce a private blocklisting framework, Half-Moon Cookie, by which a client can check an item against a proprietary blocklist held by a server, to determine whether the item is close to any blocklist element in a metric space. Critically, our design separates the embedding step from the blocklist check, enabling independent choice of methods to compute them privately and efficiently. Still, this computation might be too costly to perform on the critical path of using the item, and so our design also supports a very efficient check that an item previously passed the blocklist check. In doing so, we support applications where one client can perform the blocklist check on the item before sending it, and recipients can more efficiently confirm the previous result before using the item, thereby avoiding TOCTOU attacks. We show how Half-Moon Cookie can be instantiated for similarity-based malware detection, to block malicious executables without revealing client inputs or disclosing the blocklist.
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Cryptography and Security

Too Private to Tell: Practical Token Theft Attacks on Apple Intelligence

Apple Intelligence is a generative AI (GenAI) service provided by Apple on its devices. While offering a similar set of features as other similar GenAI services, Apple Intelligence is claimed to be designed with an extra focus on user security and privacy through a two-stage authentication and authorization design using anonymous access tokens. In this paper, we present our investigation into this token issuance mechanism with a goal to reveal possible vulnerabilities using traffic analysis, reverse engineering, and cross comparison with Apple's public documentation. Specifically, we present the Serpent attack, the first practical cross-device token replay attack against Apple Intelligence that allows the attacker to steal the access tokens from the victim's device and utilise them on a different device, with all usage rate-limited against the victim. We have achieved successful attacks on the latest macOS 26 Tahoe and demonstrated that an attacker, who even has used up its own allowance, can immediately regain access to Apple Intelligence service. We have responsibly disclosed the vulnerabilities to the vendors and received confirmation from Apple with CVE assigned and bounty given. Our results highlight a general lesson for built-in AI services: Anonymising identity does not by itself make the AI service secure; Enforcing non-transferability requires cryptographic binding to the rightful user.
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All authors Haoling Zhou, Shixuan Zhao, Chao Wang, Zhiqiang Lin

Cryptography and Security

Privacy, Prediction, and Allocation

Algorithmic predictions are increasingly used to inform the allocation of scarce resources. The promise of these methods is that, through machine learning, they can better identify the people who would benefit most from interventions. Recently, however, several works have called this assumption into question by demonstrating the existence of settings where simple, unit-level allocation strategies can meet or even exceed the performance of those based on individual-level targeting. Separately, other works have objected to individual-level targeting on privacy grounds, leading to an unusual situation where a single solution, unit-level targeting, is recommended for reasons of both privacy and utility. Motivated by the desire to fully understand the interplay of privacy and targeting levels, we initiate the study of aid allocation systems that satisfy differential privacy, synthesizing existing works on private optimization with the economic models of aid allocation used in the non-private literature. To this end, we investigate private variants of both individual and unit-level allocation strategies in both stochastic and distribution-free settings under a range of constraints on data availability. Through this analysis, we provide clean, interpretable bounds characterizing the tradeoffs between privacy, efficiency, and targeting precision in allocation.
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Thursday 16 April

Cryptography and Security

Decentralized autonomous organization and blockchain-based incentivization framework for community-based facilities management

Traditional facility management often relies on centralized decision-making structures that limit stakeholder participation, leading to misalignment with occupant needs and reduced satisfaction. This paper proposes a novel blockchain- and Decentralized Autonomous Organization (DAO)-based framework for community-based facilities management in smart buildings. The framework comprises two key components: a decentralized governance platform that facilitates transparent collective decision-making through blockchain-based voting, and a maintenance management platform with an incentivization mechanism that encourages building occupants to actively contribute to facility upkeep through tokenized rewards. System evaluation includes cost analysis, scalability, data security considerations, usability testing, and semi-structured interviews with facility managers and researchers to assess the platform's usefulness, challenges, and adoption potential. The findings demonstrate the framework's potential as a viable incentivization solution for engaging stakeholders in the collective upkeep and improvement of building infrastructure.
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All authors Reachsak Ly, Alireza Shojaei, Xinghua Gao, Philip Agee, Abiola Akanmu

Cryptography and Security

Public and private blockchain for decentralized digital building twins and building automation system

The communication protocols and data transfer mechanisms employed by IoT devices in smart buildings and corresponding digital twin systems predominantly rely on centralized architectures. Such centralized systems are vulnerable to single points of failure, where a malfunction can disrupt operational processes. This study introduces a blockchain-based decentralized protocol to enhance the cyber resilience of IoT data transfer for digital twins and enable decentralized automation of building operations. The framework incorporates public and private blockchain technologies alongside two case studies showcasing prototypes of each system. These prototypes were validated within a real-world building environment using smart home appliances and two digital twin platforms, with their performance evaluated based on cost, scalability, data security, and privacy. The findings reveal that the Hyperledger Fabric-based system excels in terms of scalability, speed, and cost-effectiveness, while both frameworks offer advantages over traditional centralized protocols in system cyber resilience, data security, and privacy.
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Cryptography and Security

Anumati: Proof of Adherence as a Formal Consent Model for Autonomous Agent Protocols

As autonomous AI agents increasingly call other agents to complete tasks on behalf of a human principal, a structural accountability gap has emerged: the calling agent accepts the terms of service of the callee without any protocol-level mechanism to prove that it understood those terms or that it subsequently honoured them. Authentication protocols such as OAuth and mutual TLS establish who may call which capability. They do not address under what conditions a permitted call may be made, and those conditions change as the callee's policies evolve. In this paper we formalise the distinction between proof of acceptance (a timestamped acknowledgement) and proof of adherence (a per-action reasoning record citing the specific clause evaluated). We propose three primitives (PolicyDocument, ConsentRecord, and AdherenceEvent) that together constitute a versioned, append-only consent model for agent-to-agent communication. The model is instantiated as a non-breaking extension to two widely used agent protocols: the Agent2Agent (A2A) protocol and the Model Context Protocol (MCP). A TLA+ specification of the consent lifecycle, together with a reference Python implementation of the chain integrity and adherence trail validators, is available in the accompanying repository.
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Cryptography and Security · Cross-listed from cs.CV

Privacy-Preserving Semantic Segmentation without Key Management

This paper proposes a novel privacy-preserving semantic segmentation method that can use independent keys for each client and image. In the proposed method, the model creator and each client encrypt images using locally generated keys, and model training and inference are conducted on the encrypted images. To mitigate performance degradation, an image encryption method is applied to model training in addition to the generation of test images. In experiments, the effectiveness of the proposed method is confirmed on the Cityscapes dataset under the use of a vision transformer-based model, called SETR.
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Cryptography and Security

CAMP: Cumulative Agentic Masking and Pruning for Privacy Protection in Multi-Turn LLM Conversations

The deployment of Large Language Models in agentic, multi-turn conversational settings has introduced a class of privacy vulnerabilities that existing protection mechanisms are not designed to address. Current approaches to Personally Identifiable Information (PII) masking operate on a per-turn basis, scanning each user message in isolation and replacing detected entities with typed placeholders before forwarding sanitized text to the model. While effective against direct identifier leakage within a single message, these methods are fundamentally stateless and fail to account for the compounding privacy risk that emerges when PII fragments accumulate across conversation turns. A user who separately discloses their name, employer, location, and medical condition across several messages has revealed a fully re-identifiable profile - yet no individual message would trigger a per-turn masker. We formalize this phenomenon as Cumulative PII Exposure (CPE) and propose CAMP (Cumulative Agentic Masking and Pruning), a cross-turn privacy protection framework for multi-turn LLM conversations. CAMP maintains a session-level PII registry, constructs a co-occurrence graph to model combination risk between entity types, computes a CPE score after each turn, and triggers retroactive masking of conversation history when the score crosses a configurable threshold. We evaluate CAMP on four synthetic multi-turn scenarios spanning healthcare, hiring, finance, and general conversation, demonstrating that per-turn baselines expose re-identifiable profiles that CAMP successfully neutralizes while preserving full conversational utility.
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Cryptography and Security

CSLE: A Reinforcement Learning Platform for Autonomous Security Management

Reinforcement learning is a promising approach to autonomous and adaptive security management in networked systems. However, current reinforcement learning solutions for security management are mostly limited to simulation environments and it is unclear how they generalize to operational systems. In this paper, we address this limitation by presenting CSLE: a reinforcement learning platform for autonomous security management that enables experimentation under realistic conditions. Conceptually, CSLE encompasses two systems. First, it includes an emulation system that replicates key components of the target system in a virtualized environment. We use this system to gather measurements and logs, based on which we identify a system model, such as a Markov decision process. Second, it includes a simulation system where security strategies are efficiently learned through simulations of the system model. The learned strategies are then evaluated and refined in the emulation system to close the gap between theoretical and operational performance. We demonstrate CSLE through four use cases: flow control, replication control, segmentation control, and recovery control. Through these use cases, we show that CSLE enables near-optimal security management in an environment that approximates an operational system.
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Cryptography and Security

A Framework for Post Quantum Migration in IoT-Based Healthcare Systems

Smart healthcare industry is increasingly relying on Internet of Things (IoT) devices to improve patient care and operational efficiency. However, the cryptographic algorithms that enable fundamental security and are widely used in these cyber systems are vulnerable to attacks by emerging quantum computers - known as Quantum Threat. This paper examines the quantum threat to healthcare IoT across the four layers of the IoT architecture: physical, network, perception, and application. It proposes a comprehensive migration framework integrating a phased hybrid approach with crypto-agility to transition healthcare IoT systems to quantum-safe cryptography. This framework prioritises resource-constrained devices, emphasises interoperability, and considers the challenges of vendor readiness and infrastructure upgrades. This paper contributes a detailed, phased migration plan specifically tailored to the unique security needs and resource limitations of IoT-based healthcare systems.
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All authors Asif Alif, Khondokar Fida Hasan, Basker Palaniswamy, Md. Morshedul Islam

Cryptography and Security · Cross-listed from cs.SE

Don't Make Models Guess Security and Safety: Symbolic Guardrails for Domain-Specific AI Agents

There is increasing interest in integrating AI agents that invoke tools into domain-specific commercial software, where unintended tool calls can cause serious security and safety incidents. This has drawn growing research attention, and many agent security and safety benchmarks have emerged. They implicitly shape how the community approaches security and safety. Yet existing work exhibits a blind spot: it emphasizes training-based methods and neural guardrails, which reduce the likelihood of insecure or unsafe actions but cannot guarantee their prevention. It generally overlooks opportunities for deductive, symbolic guardrails grounded in standard software engineering practices, which can provide guarantees for some security and safety requirements. Our study has three parts: (1) a systematic review of 80 agent security and safety benchmarks finding that that 85% of benchmarks do not state verifiable requirements (61% provide none, and 24% give only high-level goals); (2) an applicability analysis of which security and safety requirements symbolic guardrails can and cannot enforce on $\tau^2$-Bench, CAR-bench, and MedAgentBench, finding that 74% of requirements are symbolically enforceable and 95% of these need only simple, low-cost checks; and (3) an empirical evaluation of symbolic guardrails on the same three benchmarks, finding that symbolic guardrails improve security and safety without sacrificing utility, and often improve it. Our work draws attention to the potential for symbolic guardrails for AI agents, suggesting them as an overlooked but practical path toward deploying domain-specific AI agents in risk-averse commercial software. We release all codes and artifacts at https://github.com/hyn0027/agent-symbolic-guardrails.
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All authors Yining Hong, Yining She, Eunsuk Kang, Christopher S. Timperley, Christian Kästner

Cryptography and Security

SecureRouter: Encrypted Routing for Efficient Secure Inference

Cryptographically secure neural network inference typically relies on secure computing techniques such as Secure Multi-Party Computation (MPC), enabling cloud servers to process client inputs without decrypting them. Although prior privacy-preserving inference systems co-design network optimizations with MPC, they remain slow and costly, limiting real-world deployment. A major bottleneck is their use of a single, fixed transformer model for all encrypted inputs, ignoring that different inputs require different model sizes to balance efficiency and accuracy. We present SecureRouter, an end-to-end encrypted routing and inference framework that accelerates secure transformer inference through input-adaptive model selection under encryption. SecureRouter establishes a unified encrypted pipeline that integrates a secure router with an MPC-optimized model pool, enabling coordinated routing, inference, and protocol execution while preserving full data and model confidentiality. The framework includes training-phase and inference-phase components: an MPC-cost-aware secure router that predicts per-model utility and cost from encrypted features, and an MPC-optimized model pool whose architectures and quantization schemes are co-trained to minimize MPC communication and computation overhead. Compared to prior work, SecureRouter achieves a latency reduction by 1.95x with negligible accuracy loss, offering a practical path toward scalable and efficient secure AI inference. Our open-source implementation is available at: https://github.com/UCF-ML-Research/SecureRouter
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Cryptography and Security · Cross-listed from cs.LG

Evaluating LLM Simulators as Differentially Private Data Generators

LLM-based simulators offer a promising path for generating complex synthetic data where traditional differentially private (DP) methods struggle with high-dimensional user profiles. But can LLMs faithfully reproduce statistical distributions from DP-protected inputs? We evaluate this using PersonaLedger, an agentic financial simulator, seeded with DP synthetic personas derived from real user statistics. We find that PersonaLedger achieves promising fraud detection utility (AUC 0.70 at epsilon=1) but exhibits significant distribution drift due to systematic LLM biases–learned priors overriding input statistics for temporal and demographic features. These failure modes must be addressed before LLM-based methods can handle the richer user representations where they might otherwise excel.
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All authors Nassima M. Bouzid, Dehao Yuan, Nam H. Nguyen, Mayana Pereira

Cryptography and Security

HarmfulSkillBench: How Do Harmful Skills Weaponize Your Agents?

Large language models (LLMs) have evolved into autonomous agents that rely on open skill ecosystems (e.g., ClawHub and Skills.Rest), hosting numerous publicly reusable skills. Existing security research on these ecosystems mainly focuses on vulnerabilities within skills, such as prompt injection. However, there is a critical gap regarding skills that may be misused for harmful actions (e.g., cyber attacks, fraud and scams, privacy violations, and sexual content generation), namely harmful skills. In this paper, we present the first large-scale measurement study of harmful skills in agent ecosystems, covering 98,440 skills across two major registries. Using an LLM-driven scoring system grounded in our harmful skill taxonomy, we find that 4.93% of skills (4,858) are harmful, with ClawHub exhibiting an 8.84% harmful rate compared to 3.49% on Skills.Rest. We then construct HarmfulSkillBench, the first benchmark for evaluating agent safety against harmful skills in realistic agent contexts, comprising 200 harmful skills across 20 categories and four evaluation conditions. By evaluating six LLMs on HarmfulSkillBench, we find that presenting a harmful task through a pre-installed skill substantially lowers refusal rates across all models, with the average harm score rising from 0.27 without the skill to 0.47 with it, and further to 0.76 when the harmful intent is implicit rather than stated as an explicit user request. We responsibly disclose our findings to the affected registries and release our benchmark to support future research (see https://github.com/TrustAIRLab/HarmfulSkillBench).
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All authors Yukun Jiang, Yage Zhang, Michael Backes, Xinyue Shen, Yang Zhang

Cryptography and Security

Graded Symbolic Verification with a Fuzzy Dolev-Yao Attacker Model

Classical symbolic protocol verification under Dolev–Yao uses binary attacker knowledge (known/unknown). This abstraction misses cumulative side-channel settings, where repeated noisy observations progressively improve attacker knowledge. We model this process with a graded attacker view \(\mu_K\in[0,1]\), product T-norm leak updates, and finite-grid explicit-state execution in Modified Murphi. The method is optimised with exact concept-lattice attribute reducts and exposes threshold-driven safe-to-fail transitions that are not represented in corresponding binary runs under the same bounded assumptions. Executed results on symmetric and asymmetric protocols, including Needham–Schroeder–Lowe (NSL), show that baseline models passing under crisp semantics can fail once cumulative side-channel leakage is enabled.
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Cryptography and Security

LinuxArena: A Control Setting for AI Agents in Live Production Software Environments

We introduce LinuxArena, a control setting in which agents operate directly on live, multi-service production environments. LinuxArena contains 20 environments, 1,671 main tasks representing legitimate software engineering work, and 184 side tasks representing safety failures such as data exfiltration and backdooring, making it the largest and most diverse control setting for software engineering to date. We validate LinuxArena is useful for control research by running sabotage evaluations, which measure whether attackers can complete side tasks while working on main tasks, and monitor evaluations, which measure a monitor model's ability to detect sabotage attempts. Against a GPT-5-nano trusted monitor at a 1% step-wise false positive rate, Claude Opus 4.6 achieves roughly a 23% undetected sabotage success rate. We additionally release LaStraj, a dataset of human-crafted attack trajectories that evade monitors at substantially higher rates than any model-generated attacks we elicited, showing that current attack policies do not saturate LinuxArena. These results suggest that LinuxArena has meaningful headroom for both attackers and defenders, making it a strong testbed for developing and evaluating future control protocols.
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All authors Tyler Tracy, Ram Potham, Nick Kuhn, Myles Heller, Anshul Khandelwal, Cody Rushing, Henri Lemoine, Miguel Brandao, Tomas Turlik, Adam Hanson, Josh Hills, Amy Ngo, Ram Rachum, Nik Mitchell, Falko Galperin, Oscar Sykes, Pip Arnott, Samuel Prieto Lima, Carlos Giudice, Matt Goldwater, Daniel Popp, Drew de Wet, Ruben Castaing, Qi Guo, Douw Marx, Benjamin Shaffrey, Justin Shenk, Martin Milbradt, Hannah Meagher, Shaheen Ahmed-Chowdhury, Daniel O'Connell, Chris Canal, Buck Shlegeris, Aryan Bhatt

Cryptography and Security

Structural Dependency Analysis for Masked NTT Hardware: Scalable Pre-Silicon Verification of Post-Quantum Cryptographic Accelerators

Post-quantum cryptographic (PQC) accelerators implementing ML-KEM (FIPS 203) and ML-DSA (FIPS 204) require side-channel resistance evidence for FIPS 140-3 certification. However, exact masking-verification tools scale only to gadgets of a few thousand cells. We present a four-stage verification hierarchy, D0/D1 structural dependency analysis, fresh-mask refinement, Boolean Single-Authentication Distance Checking (SADC), and arithmetic SADC, that extends sound first-order masking verification to production arithmetic modules. Applied to the 1.17-million-cell Adams Bridge ML-DSA/ML-KEM accelerator, structural analysis completes in seconds across all 30 masked submodules. A multi-cycle extension (MC-D1) reclassifies 12 modules from structurally clean to structurally flagged. On the 5,543-cell ML-KEM Barrett reduction module, the pipeline machine-verifies 198 of 363 structurally flagged wires (54.5%) as first-order secure, reports 165 as candidate insecure for designer triage (a sound upper bound), and leaves 0 indeterminate. Every verdict is cross validated by Z3 and CVC5 with 0 disagreements across 363 wires. The result narrows manual review from hundreds of structural flags to 165 actionable candidates with mathematical certificates, enabling pre-silicon side-channel evidence generation on production ML-KEM hardware.
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Cryptography and Security

Feedback-Driven Execution for LLM-Based Binary Analysis

Binary analysis increasingly relies on large language models (LLMs) to perform semantic reasoning over complex program behaviors. However, existing approaches largely adopt a one-pass execution paradigm, where reasoning operates over a fixed program representation constructed by static analysis tools. This formulation limits the ability to adapt exploration based on intermediate results and makes it difficult to sustain long-horizon, multi-path analysis under constrained context. We present FORGE, a system that rethinks LLM-based analysis as a feedback-driven execution process. FORGE interleaves reasoning and tool interaction through a reasoning-action-observation loop, enabling incremental exploration and evidence construction. To address the instability of long-horizon reasoning, we introduce a Dynamic Forest of Agents (FoA), a decomposed execution model that dynamically coordinates parallel exploration while bounding per-agent context. We evaluate FORGE on 3,457 real-world firmware binaries. FORGE identifies 1,274 vulnerabilities across 591 unique binaries, achieving 72.3% precision while covering a broader range of vulnerability types than prior approaches. These results demonstrate that structuring LLM-based analysis as a decomposed, feedback-driven execution system enables both scalable reasoning and high-quality outcomes in long-horizon tasks.
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Cryptography and Security

NFTDELTA: Detecting Permission Control Vulnerabilities in NFT Contracts through Multi-View Learning

Permission control vulnerabilities in Non-fungible token (NFT) contracts can result in significant financial losses, as attackers may exploit these weaknesses to gain unauthorized access or circumvent critical permission checks. In this paper, we propose NFTDELTA, a framework that leverages static analysis and multi-view learning to detect permission control vulnerabilities in NFT contracts. Specifically, we extract comprehensive function Control Flow Graph (CFG) information via two views: sequence features (representing execution paths) and graph features (capturing structural control flow). These two views are then integrated to create a unified code representation. We also define three specific categories of permission control vulnerabilities and employ a custom detector to identify defects through multi-view feature similarity analysis. Our evaluation of 795 popular NFT collections identified 241 confirmed permission control vulnerabilities, comprising 214 cases of Bypass Auth Reentrancy, 15 of Weak Auth Validation, and 12 of Loose Permission Management. Manual verification demonstrates the detector's high reliability, achieving an average precision of 97.92% and an F1-score of 81.09%. Furthermore, NFTDELTA demonstrates enhanced efficiency and scalability, proving its effectiveness in securing NFT ecosystems.
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All authors Hailu Kuang, Xiaoqi Li, Wenkai Li, Zongwei Li

Cryptography and Security · Cross-listed from cs.LG

FedIDM: Achieving Fast and Stable Convergence in Byzantine Federated Learning through Iterative Distribution Matching

Most existing Byzantine-robust federated learning (FL) methods suffer from slow and unstable convergence. Moreover, when handling a substantial proportion of colluded malicious clients, achieving robustness typically entails compromising model utility. To address these issues, this work introduces FedIDM, which employs distribution matching to construct trustworthy condensed data for identifying and filtering abnormal clients. FedIDM consists of two main components: (1) attack-tolerant condensed data generation, and (2) robust aggregation with negative contribution-based rejection. These components exclude local updates that (1) deviate from the update direction derived from condensed data, or (2) cause a significant loss on the condensed dataset. Comprehensive evaluations on three benchmark datasets demonstrate that FedIDM achieves fast and stable convergence while maintaining acceptable model utility, under multiple state-of-the-art Byzantine attacks involving a large number of malicious clients.
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All authors He Yang, Dongyi Lv, Wei Xi, Song Ma, Hanlin Gu, Jizhong Zhao

Cryptography and Security

Emulation-based System-on-Chip Security Verification: Challenges and Opportunities

Increasing system-on-chip (SoC) heterogeneity, deep hardware/software integration, and the proliferation of third-party intellectual property (IP) have brought security validation to the forefront of semiconductor design. While simulation and formal verification remain indispensable, they often struggle to expose vulnerabilities that emerge only under realistic execution conditions, long software-driven interactions, and adversarial stimuli. In this context, hardware emulation is emerging as an increasingly important pre-silicon verification technology because it enables higher-throughput execution of RTL designs under realistic hardware/software workloads while preserving sufficient fidelity for security-oriented analysis. This paper presents a comprehensive survey and perspective on emulation-based security verification and validation. We organize the landscape of prior work across assertion-based security checking, coverage-driven exploration, adversarial testing, information-flow tracking, fault injection, and side-channel-oriented evaluation. We provide a structured view of emulation-enabled security verification workflows, including instrumentation, stimulus generation, runtime monitoring, and evidence-driven analysis. We also examine practical challenges related to observability, scalability, property specification, and the definition of security-oriented coverage metrics for emulation-based verification. Finally, we discuss emerging directions such as AI-assisted emulation, digital security twins, chiplet-scale security exploration, automated vulnerability assessment, and cloud-scale secure emulation. Overall, this paper positions emulation as a promising foundation for the next generation of pre-silicon hardware security assurance.
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All authors Tanvir Rahman, Shuvagata Saha, Ahmed Y. Alhurubi, Sujan Kumar Saha, Farimah Farahmandi, Mark Tehranipoor