Cryptography and Security
A Secure Authentication-Driven Protected Data Collection Protocol in Internet of Things
Maryam Ataei Nezhad, Hamid Barati and Ali Barati
Internet of Things means connecting different devices through the Internet. The Internet of things enables humans to remotely manage and control the objects they use with the Internet infrastructure. After the advent of the Internet of Things in homes, organizations, and private companies,
privacy and information security are the biggest concern. This issue has challenged the spread of the Internet of things as news of the users theft of information by hackers intensified. The proposed method in this paper consists of three phases. In the first phase, a
star structure is constructed within each cluster, and a unique key is shared between each child and parent to encrypt and secure subsequent communications. The second phase is for intracluster communications, in which members of the cluster send their data to the cluster head in a multi hop manner. Also, in this phase, the data is encrypted with different keys in each hop, and at the end of each connection, the keys are updated to ensure data security. The third phase is to improve the security of inter cluster communications using an authentication protocol. In this way, the cluster heads are authenticated before sending information to prevent malicious nodes in the network. The proposed method is also simulated using NS2 software. The results showed that the proposed method has improved in terms of energy consumption, end-to-end delay, flexibility, packet delivery rate, and the number of alive nodes compared to other methods.
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Cryptography and Security
Comparison of Fully Homomorphic Encryption and Garbled Circuit Techniques in Privacy-Preserving Machine Learning Inference
Kalyan Cheerla, Lotfi Ben Othmane and Kirill Morozov
Machine Learning (ML) is making its way into fields such as healthcare, finance, and Natural
Language Processing (NLP), and concerns over data
privacy and model confidentiality continue to grow.
Privacy-preserving Machine Learning (PPML) addresses this challenge by enabling inference on private data without revealing sensitive inputs or proprietary models. Leveraging Secure Computation techniques from Cryptography, two widely studied approaches in this domain are Fully Homomorphic Encryption (FHE) and Garbled
Circuits (GC). This work presents a comparative evaluation of FHE and GC for secure neural network inference. A two-layer neural network (NN) was implemented using the CKKS scheme from the Microsoft SEAL library (FHE) and the TinyGarble2.0 framework (GC) by IntelLabs. Both implementations are evaluated under the semi-honest threat model, measuring inference output error, round-trip time, peak
memory usage, communication overhead, and communication rounds. Results reveal a trade-off: modular GC offers faster execution and lower
memory consumption, while FHE supports non-interactive inference.
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Cryptography and Security
PATCH: Mitigating PII Leakage in Language Models with Privacy-Aware Targeted Circuit PatcHing
Anthony Hughes, Vasisht Duddu, N. Asokan et al. (+2 more)
Language models (LMs) may memorize personally identifiable information (PII) from training data, enabling adversaries to extract it during inference. Existing defense mechanisms such as differential
privacy (DP) reduce this leakage, but incur large drops in utility. Based on a comprehensive study using
circuit discovery to identify the computational
circuits responsible PII leakage in LMs, we hypothesize that specific PII leakage
circuits in LMs should be responsible for this behavior. Therefore, we propose PATCH (
Privacy-Aware Targeted
Circuit PatcHing), a novel approach that first identifies and subsequently directly edits PII
circuits to reduce leakage. PATCH achieves better
privacy-utility trade-off than existing defenses, e.g., reducing recall of PII leakage from LMs by up to 65%. Finally, PATCH can be combined with DP to reduce recall of residual leakage of an LM to as low as 0.01%. Our analysis shows that PII leakage
circuits persist even after the application of existing defense mechanisms. In contrast, PATCH can effectively mitigate their impact.
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All authors Anthony Hughes, Vasisht Duddu, N. Asokan, Nikolaos Aletras, Ning Ma
Cryptography and Security · Cross-listed from cs.AR
Cocoon: A System Architecture for Differentially Private Training with Correlated Noises
Donghwan Kim, Xin Gu, Jinho Baek et al. (+6 more)
Machine learning (ML) models memorize and leak training data, causing serious
privacy issues to data owners. Training
algorithms with differential
privacy (DP) have been gaining
attention as a solution. However, these
algorithms add noise at each training iteration and degrade accuracy, limiting their real-world adoption. To improve accuracy, a new family of approaches adds carefully designed correlated noises, so that noises cancel out each other across iterations. We performed an extensive characterization study of these new mechanisms and show they incur non-negligible overheads when the model is relatively large or uses large
embedding tables compared to the hardware capacity. Motivated by the analysis, we propose Cocoon, a framework for efficient training with correlated noises. Cocoon stores and processes the large noise history across CPU, GPU, and
memory extension module, introduces optimizations for sparse
embedding tables, and leverages to-be-commercialized near-
memory processing (NMP) devices. On a real system with an FPGA-based NMP device prototype, Cocoon improves the performance by 1.23-10.82x.
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All authors Donghwan Kim, Xin Gu, Jinho Baek, Timothy Lo, Younghoon Min, Kwangsik Shin, Jongryool Kim, Jongse Park, Kiwan Maeng
Cryptography and Security
Approximate Gaussian Mapping for Generative Image Steganography
Yuhua Xu, Wei Sun, Chengpei Tang et al. (+3 more)
Ordinary differential equation (ODE)-based
diffusion models enable deterministic image synthesis, establishing a reversible mapping suitable for generative steganography. While prevailing methods strictly adhere to a standard normal prior, empirical evidence indicates that controlled deviations from this distribution reduce numerical inversion errors without compromising perceptual quality. Leveraging this observation, the Approximate Gaussian Mapping (AGM) is proposed as a linear transformation strategy that embeds secrets by modulating noise scale and variance. To balance
retrieval numerical consistence and security, a two-stage decoupled optimization strategy is introduced to minimize the Kullback-Leibler divergence subject to target bit accuracy constraints. Beyond the proposed method, we conduct a mechanistic analysis of the divergent behaviors between pixel-space and latent-space architectures. The experimental results reveal that the VAE encoder enhances robustness by filtering external perturbations, whereas the structural regularization of the VAE decoder and the semantic variance introduced by text
prompts jointly mask
embedding artifacts to improve security. Experimental results confirm that pixel-space mplementations maximize
embedding capacity for lossless channels, while latent-space approaches offer superior robustness and security suitable for
adversarial environments
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All authors Yuhua Xu, Wei Sun, Chengpei Tang, Jiaxing Lu, Jingying Zhou, Chen Gu
Cryptography and Security · Cross-listed from quant-ph
Covert Quantum Learning: Privately and Verifiably Learning from Quantum Data
Abhishek Anand, Matthias C. Caro, Ari Karchmer et al. (+1 more)
Quantum learning from remotely accessed
quantum compute and data must address two key challenges: verifying the correctness of data and ensuring the
privacy of the learner's data-collection strategies and resulting conclusions. The covert (verifiable) learning model of Canetti and Karchmer (TCC 2021) provides a framework for endowing classical learning
algorithms with such guarantees. In this work, we propose models of covert verifiable learning in
quantum learning theory and realize them without computational hardness assumptions for remote data access scenarios motivated by established
quantum data advantages. We consider two
privacy notions: (i) strategy-covertness, where the eavesdropper does not gain information about the learner's strategy; and (ii) target-covertness, where the eavesdropper does not gain information about the unknown object being learned. We show: Strategy-covert
algorithms for making
quantum statistical queries via classical shadows; Target-covert
algorithms for learning quadratic functions from public
quantum examples and private
quantum statistical queries, for Pauli shadow
tomography and stabilizer state learning from public multi-copy and private single-copy
quantum measurements, and for solving Forrelation and Simon's problem from public
quantum queries and private classical queries, where the adversary is a unidirectional or i.i.d. ancilla-free eavesdropper. The lattermost results in particular establish that the exponential separation between classical and
quantum queries for Forrelation and Simon's problem survives under covertness constraints. Along the way, we design covert verifiable protocols for
quantum data acquisition from public
quantum queries which may be of independent interest. Overall, our models and corresponding
algorithms demonstrate that
quantum advantages are privately and verifiably achievable even with untrusted, remote data.
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All authors Abhishek Anand, Matthias C. Caro, Ari Karchmer, Saachi Mutreja
Cryptography and Security
Exposing LLM User Privacy via Traffic Fingerprint Analysis: A Study of Privacy Risks in LLM Agent Interactions
Yixiang Zhang, Xinhao Deng, Zhongyi Gu et al. (+4 more)
Large
Language Models (LLMs) are increasingly deployed as
agents that orchestrate tasks and integrate external tools to execute complex workflows. We demonstrate that these interactive behaviors leave distinctive fingerprints in encrypted traffic exchanged between users and LLM
agents. By analyzing traffic patterns associated with
agent workflows and tool invocations, adversaries can infer
agent activities, distinguish specific
agents, and even profile sensitive user attributes. To highlight this risk, we develop AgentPrint, which achieves an F1-score of 0.866 in
agent identification and attains 73.9% and 69.1% top-3 accuracy in user attribute inference for simulated- and real-user settings, respectively. These results uncover an overlooked risk: the very interactivity that empowers LLM
agents also exposes user
privacy, underscoring the urgent need for technical countermeasures alongside regulatory and policy safeguards.
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All authors Yixiang Zhang, Xinhao Deng, Zhongyi Gu, Yihao Chen, Ke Xu, Qi Li, Jianping Wu
Cryptography and Security
A multi-layered embedded intrusion detection framework for programmable logic controllers
Rishabh Das. Aaron Werth and Tommy Morris
Industrial control system (ICS) operations use trusted endpoints like human machine interfaces (HMIs) and workstations to relay commands to programmable logic controllers (PLCs). Because most PLCs lack layered defenses, compromise of a trusted endpoint can drive unsafe actuator commands and risk safety-critical operation. This research presents an embedded intrusion detection system that runs inside the controller and uses header-level telemetry to detect and respond to network attacks. The system combines a semi-supervised anomaly detector and a supervised attack classifier. We evaluate the approach on a midstream oil-terminal testbed using three
datasets collected during tanker-truck loading. The anomaly detector achieves zero missed attacks, corresponding to 0.998 Matthews correlation. The supervised stage attains 97.37 percent hold-out accuracy and 97.03 percent external accuracy. The embedded design adds a median of 2,031 microseconds of end-to-end latency and does not impact PLC's cycle time. The proposed architecture provides a multi-layer embedded security that meets the real-time requirements of an industrial system.
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Cryptography and Security · Cross-listed from cs.IT
Differentially Private Spectral Graph Clustering: Balancing Privacy, Accuracy, and Efficiency
Antti Koskela, Mohamed Seif, H. Vincent Poor et al. (+1 more)
We study spectral graph clustering under edge differential
privacy. We propose a
matrix shuffling mechanism that combines randomized edge flipping with a random permutation of the adjacency
matrix. While edge flipping alone provides only a constant $\varepsilon$ guarantee as the graph grows, shuffling amplifies
privacy so that the effective $\varepsilon$ tends to zero with the number of nodes. We develop a unified error analysis framework – based on Davis–Kahan perturbation theory and a classification-margin bound – that gives explicit misclassification rates for all the mechanisms considered as a function of the
privacy budget, eigengap, and number of communities. Applying this framework, we show that the
matrix shuffling mechanism achieves an error rate scaling of $\tilde{O}(1/n)$, a clear improvement over two canonical DP baselines from the private PCA literature: the Gaussian mechanism applied directly to the adjacency
matrix (Analyze Gauss) and the noisy power method, both of which scale as $\tilde{O}(1)$ in $n$. We further propose a private spectral gap detection
algorithm for estimating the number of communities. Experiments on synthetic and real-world networks validate our theoretical findings.
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All authors Antti Koskela, Mohamed Seif, H. Vincent Poor, Andrea J. Goldsmith
Cryptography and Security
GNN-enhanced Traffic Anomaly Detection for Next-Generation SDN-Enabled Consumer Electronics
Guan-Yan Yang, Farn Wang and Kuo-Hui Yeh
Consumer electronics (CE) connected to the Internet of Things are susceptible to various attacks, including DDoS and web-based threats, which can compromise their functionality and facilitate remote hijacking. These vulnerabilities allow attackers to exploit CE for broader system attacks while enabling the propagation of malicious code across the CE network, resulting in device failures. Existing deep learning-based traffic anomaly detection systems exhibit high accuracy in traditional network environments but are often overly complex and reliant on static infrastructure, necessitating manual configuration and management. To address these limitations, we propose a scalable network model that integrates Software-defined Networking (SDN) and Compute First Networking (CFN) for next-generation CE networks. In this network model, we propose a Graph Neural Networks-based Network Anomaly Detection framework (GNN-NAD) that integrates SDN-based CE networks and enables the CFN architecture. GNN-NAD uniquely fuses a static, vulnerability-aware attack graph with dynamic traffic features, providing a holistic view of network security. The core of the framework is a GNN model (GSAGE) for graph representation learning, followed by a Random Forest (RF) classifier. This design (GSAGE+RF) demonstrates superior performance compared to existing feature selection methods. Experimental evaluations on CE environment reveal that GNN-NAD achieves superior metrics in accuracy, recall, precision, and F1 score, even with small sample sizes, exceeding the performance of current network anomaly detection methods. This work advances the security and efficiency of next-generation intelligent CE networks.
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Cryptography and Security
Pseudo-MDPs: A Novel Framework for Efficiently Optimizing Last Revealer Seed Manipulations in Blockchains
Maxime Reynouard
This study tackles the computational challenges of solving Markov Decision Processes (MDPs) for a restricted class of problems. It is motivated by the Last Revealer Attack (LRA), which undermines
fairness in some Proof-of-Stake (PoS) blockchains such as Ethereum (\$400B market capitalization). We introduce pseudo-MDPs (pMDPs) a framework that naturally models such problems and propose two distinct problem reductions to standard MDPs. One problem reduction provides a novel, counter-intuitive perspective, and combining the two problem reductions enables significant improvements in dynamic programming algorithms such as value iteration. In the case of the LRA which size is parameterized by $\kappa$ (in Ethereum's case $\kappa$= 325), we reduce the computational complexity from $O(2^\kappa \kappa^{2^{\kappa+2}})$ to $O(\kappa^4)$ (per iteration). This solution also provide the usual benefits from Dynamic Programming solutions: exponentially fast convergence toward the optimal solution is guaranteed. The dual perspective also simplifies policy extraction, making the approach well-suited for resource-constrained
agents who can operate with very limited
memory and computation once the problem has been solved. Furthermore, we generalize those results to a broader class of MDPs, enhancing their applicability. The framework is validated through two case studies: a fictional card game and the LRA on the Ethereum random seed consensus protocol. These applications demonstrate the framework's ability to solve large-scale problems effectively while offering actionable insights into optimal strategies. This work advances the study of MDPs and contributes to understanding security vulnerabilities in blockchain systems.
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Cryptography and Security
RedTWIZ: Diverse LLM Red Teaming via Adaptive Attack Planning
Artur Horal, Daniel Pina, Henrique Paz et al. (+7 more)
This paper presents the
vision, scientific contributions, and technical details of RedTWIZ: an adaptive and diverse multi-turn red teaming framework, to audit the robustness of Large
Language Models (LLMs) in AI-assisted software development. Our work is driven by three major research streams: (1) robust and systematic assessment of LLM conversational jailbreaks; (2) a diverse generative multi-turn attack suite, supporting compositional, realistic and goal-oriented jailbreak conversational strategies; and (3) a hierarchical attack planner, which adaptively plans, serializes, and triggers attacks tailored to specific LLM's vulnerabilities. Together, these contributions form a unified framework – combining assessment, attack generation, and strategic planning – to comprehensively evaluate and expose weaknesses in LLMs' robustness. Extensive evaluation is conducted to systematically assess and analyze the performance of the overall system and each component. Experimental results demonstrate that our multi-turn
adversarial attack strategies can successfully lead state-of-the-art LLMs to produce unsafe generations, highlighting the pressing need for more research into enhancing LLM's robustness.
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All authors Artur Horal, Daniel Pina, Henrique Paz, Iago Paulo, João Soares, Rafael Ferreira, Diogo Tavares, Diogo Glória-Silva, João Magalhães, David Semedo
Cryptography and Security
VelLMes: A high-interaction AI-based deception framework
Muris Sladić, Veronica Valeros, Carlos Catania et al. (+1 more)
There are very few SotA deception systems based on Large
Language Models. The existing ones are limited only to simulating one type of service, mainly SSH shells. These systems - but also the deception technologies not based on LLMs - lack an extensive evaluation that includes human attackers. Generative AI has recently become a valuable asset for cybersecurity researchers and practitioners, and the field of cyber-deception is no exception. Researchers have demonstrated how LLMs can be leveraged to create realistic-looking honeytokens, fake users, and even simulated systems that can be used as honeypots. This paper presents an AI-based deception framework called VelLMes, which can simulate multiple protocols and services such as SSH Linux shell, MySQL, POP3, and HTTP. All of these can be deployed and used as honeypots, thus VelLMes offers a variety of choices for deception design based on the users' needs. VelLMes is designed to be attacked by humans, so interactivity and realism are key for its performance. We evaluate the generative capabilities and the deception capabilities. Generative capabilities were evaluated using unit tests for LLMs. The results of the unit tests show that, with careful prompting, LLMs can produce realistic-looking responses, with some LLMs having a 100% passing rate. In the case of the SSH Linux shell, we evaluated deception capabilities with 89 human attackers. The results showed that about 30% of the attackers thought that they were interacting with a real system when they were assigned an LLM-based honeypot. Lastly, we deployed 10 instances of the SSH Linux shell honeypot on the Internet to capture real-life attacks. Analysis of these attacks showed us that LLM honeypots simulating Linux shells can perform well against unstructured and unexpected attacks on the Internet, responding correctly to most of the issued commands.
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All authors Muris Sladić, Veronica Valeros, Carlos Catania, Sebastian Garcia
Cryptography and Security
I Can't Patch My OT Systems! A Look at CISA's KEVC Workarounds & Mitigations for OT
Philip Huff, Nishka Gandu and Pavel Novák
We examine the state of publicly available information about known exploitable vulnerabilities applicable to operational technology (OT) environments. Specifically, we analyze the Known Exploitable Vulnerabilities Catalog (KEVC) maintained by the US Department of Homeland Security Cybersecurity and Infrastructure Security Agency (CISA) to assess whether currently available data is sufficient for effective and reliable remediation in OT settings. Our team analyzed all KEVC entries through July 2025 to determine the extent to which OT environments can rely on existing remediation recommendations. We found that although most entries in the KEVC could affect OT environments, only 13% include vendor workarounds or mitigations as alternatives to patching. This paper also examines the feasibility of developing such alternatives based on vulnerability and exploit characteristics, and we present early evidence of success with this approach.
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Cryptography and Security · Cross-listed from quant-ph
The Knowledge Complexity of Quantum Problems
Giulio Malavolta
Foundational results in theoretical computer science have established that everything provable, is provable in zero knowledge. However, this assertion fundamentally assumes a classical interpretation of computation and many interesting physical statements that one can hope to prove are not characterized. In this work, we consider decision problems, where the problem instance itself is specified by a (pure)
quantum state. We discuss several motivating examples for this notion and, as our main technical result, we show that every
quantum problem that is provable with an interactive protocol, is also provable in zero-knowledge. Our protocol achieves unconditional soundness and computational zero-knowledge, under standard assumptions in cryptography. In addition, we show how our techniques yield a protocol for the Uhlmann transformation problem that achieves a meaningful notion of zero-knowledge, also in the presence of a malicious verifier.
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Cryptography and Security · Cross-listed from cs.IT
Multi-hop Deep Joint Source-Channel Coding with Deep Hash Distillation for Semantically Aligned Image Recovery
Didrik Bergström, Deniz Gündüz and Onur Günlü
We consider image transmission via deep joint source-channel coding (DeepJSCC) over multi-hop additive white Gaussian noise (AWGN) channels by training a DeepJSCC encoder-decoder pair with a pre-trained deep hash
distillation (DHD) module to semantically cluster images, facilitating security-oriented applications through enhanced semantic consistency and improving the perceptual reconstruction quality. We train the DeepJSCC module to both reduce mean square error (MSE) and minimize cosine distance between DHD hashes of source and reconstructed images. Significantly improved perceptual quality as a result of semantic
alignment is illustrated for different multi-hop settings, for which classical DeepJSCC may suffer from noise accumulation, measured by the learned perceptual image patch similarity (LPIPS) metric.
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Cryptography and Security
Exposing Citation Vulnerabilities in Generative Engines
Riku Mochizuki, Shusuke Komatsu, Souta Noguchi et al. (+1 more)
We analyze answers generated by generative engines (GEs) from the perspectives of citation publishers and the content-injection barrier, defined as the difficulty for attackers to manipulate answers to user
prompts by placing malicious content on the web. GEs integrate two functions: web search and answer generation that cites web pages using large
language models. Because anyone can publish information on the web, GEs are vulnerable to poisoning attacks. Existing studies of citation evaluation focus on how faithfully answer content reflects cited sources, leaving unexamined which web sources should be selected as citations to defend against poisoning attacks. To fill this gap, we introduce evaluation criteria that assess poisoning threats using the citation information contained in answers. Our criteria classify the publisher attributes of citations to estimate the content-injection barrier thereby revealing the threat of poisoning attacks in current GEs. We conduct experiments in political domains in Japan and the United States (U.S.) using our criteria and show that citations from official party websites (primary sources) are approximately \(25\%\)–\(45\%\) in the U.S. and \(60\%\)–\(65\%\) in Japan, indicating that U.S. political answers are at higher risk of poisoning attacks. We also find that sources with low content-injection barriers are frequently cited yet are poorly reflected in answer content. To mitigate this threat, we discuss how publishers of primary sources can increase exposure of their web content in answers and show that well-known techniques are limited by
language differences.
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All authors Riku Mochizuki, Shusuke Komatsu, Souta Noguchi, Kazuto Ataka
Cryptography and Security
Bionetta: Efficient Client-Side Zero-Knowledge Machine Learning Proving
Dmytro Zakharov, Oleksandr Kurbatov, Artem Sdobnov et al. (+10 more)
In this report, we compare the performance of our UltraGroth-based zero-knowledge machine learning framework Bionetta to other tools of similar purpose such as EZKL, Lagrange's deep-prove, or zkml. The results show a significant boost in the proving time for custom-crafted neural networks: they can be proven even on mobile devices, enabling numerous client-side proving applications. While our scheme increases the cost of one-time preprocessing steps, such as
circuit compilation and generating trusted setup, our approach is, to the best of our knowledge, the only one that is deployable on the native EVM smart contracts without overwhelming proof size and verification overheads.
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All authors Dmytro Zakharov, Oleksandr Kurbatov, Artem Sdobnov, Lev Soukhanov, Yevhenii Sekhin, Vitalii Volovyk, Mykhailo Velykodnyi, Mark Cherepovskyi, Kyrylo Baibula, Lasha Antadze, Pavlo Kravchenko, Volodymyr Dubinin, Yaroslav Panasenko
Cryptography and Security
Differentially Private Synthetic Text Generation for Retrieval-Augmented Generation (RAG)
Junki Mori, Kazuya Kakizaki, Taiki Miyagawa et al. (+1 more)
Retrieval-Augmented Generation (RAG) enhances large
language models (LLMs) by grounding them in external knowledge. However, its application in sensitive domains is limited by
privacy risks. Existing private RAG methods typically rely on query-time differential
privacy (DP), which requires repeated noise injection and leads to accumulated
privacy loss. To address this issue, we propose DP-SynRAG, a framework that uses LLMs to generate differentially private synthetic RAG databases. Unlike prior methods, the synthetic text can be reused once created, thereby avoiding repeated noise injection and additional
privacy costs. To preserve essential information for downstream RAG tasks, DP-SynRAG extends private prediction, which instructs LLMs to generate text that mimics subsampled database records in a DP manner. Experiments show that DP-SynRAG achieves superior performance to the state-of-the-art private RAG systems while maintaining a fixed
privacy budget, offering a scalable solution for
privacy-preserving RAG.
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All authors Junki Mori, Kazuya Kakizaki, Taiki Miyagawa, Jun Sakuma
Cryptography and Security · Cross-listed from math.RT
Representation Gap of the Motzkin Monoid
Katharina Arms
The linear decomposition attack reveals a vulnerability in encryption
algorithms operating within groups or monoids with excessively small representations. The representation gap, defined as the size of the smallest non-trivial representation, therefore serves as a metric to assess the security of these
algorithms. This paper will demonstrate that the diagrammatic Motzkin monoids exhibit a large representation gap, positioning them as promising candidates for robust encryption
algorithms.
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Cryptography and Security · Cross-listed from cs.LG
Is the Hard-Label Cryptanalytic Model Extraction Really Polynomial?
Akira Ito, Takayuki Miura and Yosuke Todo
Deep Neural Networks (DNNs) have attracted significant
attention, and their internal models are now considered valuable intellectual assets. Extracting such a model via oracle access to a DNN is conceptually similar to extracting a secret key from a block cipher. Consequently, cryptanalytic techniques, particularly differential-like attacks, have been actively explored. ReLU-based DNNs are the most common and widely deployed architectures. While early works (e.g., Crypto 2020, Eurocrypt 2024) assume access to exact output logits, which are typically not exposed, more recent works (e.g., Asiacrypt 2024, Eurocrypt 2025) focus on the hard-label setting, where only the final classification result (e.g., "dog" or "car") is available. Notably, Carlini et al. (Eurocrypt 2025) showed that model extraction is feasible in
polynomial time even under this restricted setting. In this paper, we show that a key assumption underlying their attack becomes increasingly unrealistic as the target depth grows. While prior works noted
neurons whose activation states rarely change, we analyze their concrete impact on hard-label extraction: even a single
neuron that is (almost) always active can prevent the attack from proceeding unless its parameters are recovered, and ignoring it incurs a non-negligible error. A straightforward solution is to extract these parameters by observing a state switch of such a
neuron, but observing such a switch becomes exponentially harder as depth increases, implying that hard-label extraction is not always
polynomial time. To address this limitation, we propose a novel attack called cross-layer extraction. Rather than extracting secret parameters (e.g., weights and biases) directly, we exploit cross-layer interactions to recover them from deeper layers, reducing query complexity and addressing limitations of existing approaches.
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Cryptography and Security
Distilling Lightweight Language Models for C/C++ Vulnerabilities
Zhiyuan Wei, Xiaoxuan Yang, Jing Sun et al. (+1 more)
The increasing complexity of modern software systems exacerbates the prevalence of security vulnerabilities, posing risks of severe breaches and substantial economic loss. Consequently, robust code vulnerability detection is essential for software security. While Large
Language Models (LLMs) have demonstrated remarkable capabilities in natural
language processing, their potential for automated code vulnerability detection remains underexplored. This paper presents FineSec, a novel framework that harnesses LLMs through knowledge
distillation to enable efficient and precise vulnerability identification in C/C++ codebases. FineSec utilizes knowledge
distillation to transfer expertise from large teacher models to compact student models, achieving high accuracy with minimal computational cost. By integrating data preparation, training, evaluation, and continuous learning into a unified, single-task workflow, FineSec offers a streamlined approach. Extensive evaluations on C/C++ codebases demonstrate its superiority over both base models and larger LLMs in identifying complex vulnerabilities and logical flaws, establishing FineSec as a practical and scalable solution for real-world software security. To facilitate reproducibility, the
datasets, source code, and experimental results are made publicly available at: https://github.com/yangxiaoxuan123/FineSec_detect.
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All authors Zhiyuan Wei, Xiaoxuan Yang, Jing Sun, Zijian Zhang
Cryptography and Security
Unsupervised Backdoor Detection and Mitigation for Spiking Neural Networks
Jiachen Li, Bang Wu, Xiaoyu Xia et al. (+3 more)
Spiking Neural Networks (SNNs) have gained increasing
attention for their superior energy efficiency compared to Artificial Neural Networks (ANNs). However, their security aspects, particularly under
backdoor attacks, have received limited
attention. Existing defense methods developed for ANNs perform poorly or can be easily bypassed in SNNs due to their event-driven and temporal dependencies. This paper identifies the key blockers that hinder traditional
backdoor defenses in SNNs and proposes an unsupervised post-training detection framework, Temporal Membrane Potential
Backdoor Detection (TMPBD), to overcome these challenges. TMPBD leverages the maximum margin statistics of temporal membrane potential (TMP) in the final spiking layer to detect target labels without any attack knowledge or data access. We further introduce a robust mitigation mechanism, Neural Dendrites Suppression
Backdoor Mitigation (NDSBM), which clamps dendritic connections between early convolutional layers to suppress malicious
neurons while preserving benign behaviors, guided by TMP extracted from a small, clean, unlabeled
dataset. Extensive experiments on multiple neuromorphic
benchmarks and state-of-the-art input-aware dynamic trigger attacks demonstrate that TMPBD achieves 100% detection accuracy, while NDSBM reduces the attack success rate from 100% to 8.44%, and to 2.81% when combined with detection, without degrading clean accuracy.
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All authors Jiachen Li, Bang Wu, Xiaoyu Xia, Xiaoning Liu, Xun Yi, Xiuzhen Zhang
Cryptography and Security
Your Harness is Not Secure: Benchmarking Real-world Threat of Command Line Interface Agent
Weidi Luo, Qiming Zhang, Tianyu Lu et al. (+9 more)
Command-line interface (CLI)
agents powered by large
language models (LLMs) can interpret natural-
language requests, plan multi-step tasks, execute shell commands, and modify files and system state. As these
agents are increasingly used for operating-system (OS) workflows, it is important to evaluate whether they can be misused to carry out security-relevant operations. Existing
benchmarks often lack an attacker-knowledge model grounded in tactics, techniques, and procedures (TTPs), provide limited coverage of end-to-end kill chains, rely on simplified single-host environments, or use LLM-as-a-judge for success evaluation. We introduce AdvCLI, an MITRE ATT&CK-aligned
benchmark for evaluating OS-level misuse risks of CLI
agents in a controlled multi-host sandbox. AdvCLI contains 140 tasks: 40 direct malicious requests, 74 TTP-based tasks, and 26 end-to-end kill chains. Each task is paired with deterministic hard-coded verification protocols that check whether the requested OS-level effect is realized. We evaluate seven CLI
agents and products built on nine foundation models, including ReAct, OpenClaw, OpenAI
Agent SDK, Claude Code, Gemini CLI, Cursor CLI, and Cursor IDE. Results show that current CLI
agents frequently proceed beyond refusal and can complete a non-negligible fraction of malicious OS-level tasks, especially when requests include TTP-style attacker knowledge. AdvCLI provides a reproducible testbed for evaluating these risks and for developing stronger safety mechanisms for tool-using CLI
agents in the future.
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All authors Weidi Luo, Qiming Zhang, Tianyu Lu, Xiaogeng Liu, Bin Hu, Hung-Chun Chiu, Siyuan Ma, Yizhe Zhang, Xusheng Xiao, Yinzhi Cao, Zhen Xiang, Chaowei Xiao
Cryptography and Security
Reading Between the Lines: Towards Reliable Black-box LLM Fingerprinting via Zeroth-order Gradient Estimation
Shuo Shao, Yiming Li, Hongwei Yao et al. (+3 more)
The substantial investment required to develop Large
Language Models (LLMs) makes them valuable intellectual property, raising significant concerns about copyright protection. LLM fingerprinting has emerged as a key technique to address this, which aims to verify a model's origin by extracting an intrinsic, unique signature (a "fingerprint") and comparing it to that of a source model to identify illicit copies. However, existing black-box fingerprinting methods often fail to generate distinctive LLM fingerprints. This ineffectiveness arises because black-box methods typically rely on model outputs, which lose critical information about the model's unique parameters due to the usage of non-linear functions. To address this, we first leverage Fisher Information Theory to formally demonstrate that the gradient of the model's input is a more informative feature for fingerprinting than the output. Based on this insight, we propose ZeroPrint, a novel method that approximates these information-rich gradients in a black-box setting using zeroth-order estimation. ZeroPrint overcomes the challenge of applying this to discrete text by simulating input perturbations via semantic-preserving word substitutions. This operation allows ZeroPrint to estimate the model's Jacobian
matrix as a unique fingerprint. Experiments on the standard
benchmark show ZeroPrint achieves a state-of-the-art effectiveness and robustness, significantly outperforming existing black-box methods.
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All authors Shuo Shao, Yiming Li, Hongwei Yao, Yifei Chen, Yuchen Yang, Zhan Qin
Cryptography and Security
Auto-Stega: An Agent-Driven System for Lifelong Strategy Evolution in LLM-Based Text Steganography
Jiuan Zhou, Yu Cheng, Yuan Xie et al. (+1 more)
With the rapid progress of LLMs, high quality generative text has become widely available as a cover for text steganography. However, prevailing methods rely on hand-crafted or pre-specified strategies and struggle to balance efficiency, imperceptibility, and security, particularly at high
embedding rates. Accordingly, we propose Auto-Stega, an
agent-driven self-evolving framework that is the first to realize self-evolving steganographic strategies by automatically discovering, composing, and adapting strategies at inference time; the framework operates as a closed loop of generating, evaluating, summarizing, and updating that continually curates a structured strategy library and adapts across corpora, styles, and task constraints. A decoding LLM recovers the information under the shared strategy. To handle high
embedding rates, we introduce PC-DNTE, a plug-and-play
algorithm that maintains
alignment with the base model's conditional distribution at high
embedding rates, preserving imperceptibility while enhancing security. Experimental results demonstrate that at higher
embedding rates Auto-Stega achieves superior performance with gains of 42.2% in perplexity and 1.6% in anti-steganalysis performance over SOTA methods.
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All authors Jiuan Zhou, Yu Cheng, Yuan Xie, Zhaoxia Yin
Cryptography and Security · Cross-listed from cs.SD
Benchmarking Fake Voice Detection in the Fake Voice Generation Arms Race
Xutao Mao, Ke Li, Cameron Baird et al. (+2 more)
The rapid advancement of fake voice generation technology has ignited a race with detection systems, creating an urgent need to secure the audio ecosystem. However, existing
benchmarks suffer from a critical limitation: they typically aggregate diverse fake voice samples into a single
dataset for evaluation. This practice masks method-specific artifacts and obscures the varying performance of detectors against different generation paradigms, preventing a nuanced understanding of their true vulnerabilities. To address this gap, we introduce the first ecosystem-level
benchmark that systematically evaluates the interplay between 17 state-of-the-art fake voice generators and 8 leading detectors through a novel one-to-one evaluation protocol. This fine-grained analysis exposes previously hidden vulnerabilities and sensitivities that are missed by traditional aggregated testing. We also propose unified scoring systems to quantify both the evasiveness of generators and the robustness of detectors, enabling fair and direct comparisons. Our extensive cross-domain evaluation reveals that modern generators, particularly those based on neural audio codecs and flow matching, consistently evade top-tier detectors. We found that no single detector is universally robust; their effectiveness varies dramatically depending on the generator's architecture, highlighting a significant generalization gap in current defenses. This work provides a more realistic assessment of the threat landscape and offers actionable insights for building the next generation of detection systems.
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All authors Xutao Mao, Ke Li, Cameron Baird, Ezra Xuanru Tao, Dan Lin
Cryptography and Security
SpyChain: Multi-Vector Supply Chain Attacks on Small Satellite Systems
Jack Vanlyssel, Enrique Sobrados, Ramsha Anwar et al. (+2 more)
Small satellites are integral to scientific, commercial, and defense missions, but reliance on commercial off-the-shelf (COTS) hardware broadens their attack surface. Although supply chain threats are well studied in other cyber-physical domains, their feasibility and stealth in space systems remain largely unexplored. Prior work has focused on flight software, which benefits from strict security practices and oversight. In contrast, auxiliary COTS components often lack robust assurance yet enjoy comparable access to critical on-board resources, including telemetry, system calls, and the software bus. Despite this privileged access, the insider threat within COTS hardware supply chains has received little
attention. In this work, we present SpyChain, the first end-to-end design and implementation of independent and colluding hardware supply chain threats targeting small satellites. Using NASA's satellite simulation (NOS3), we demonstrate that SpyChain can evade testing, exfiltrate telemetry, disrupt operations, and launch Denial of Service (DoS) attacks through covert channels that bypass ground monitoring. Our study traces an escalation from a simple solo component to dynamic, coordinating malware, introducing a taxonomy of stealth across five scenarios. We showcase how implicit trust in auxiliary components enables covert persistence and reveal novel attack vectors, highlighting a new multi-component execution technique that is now incorporated into the SPARTA
matrix. Our findings are reinforced by acknowledgment and affirmation from NASA's NOS3 team. Finally, we implement lightweight onboard defenses, including runtime monitoring, to mitigate threats like SpyChain.
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All authors Jack Vanlyssel, Enrique Sobrados, Ramsha Anwar, Gruia-Catalin Roman, Afsah Anwar
Cryptography and Security
From Description to Detection: LLM based Extendable O-RAN Compliant Blind DoS Detection in 5G and Beyond
Thusitha Dayaratne, Ngoc Duy Pham, Viet Vo et al. (+5 more)
The quality and experience of mobile communication have significantly improved with the introduction of 5G, and these improvements are expected to continue beyond the 5G era. However, vulnerabilities in control-plane protocols, such as
Radio Resource Control (RRC) and Non-Access Stratum (NAS), pose significant security threats, such as Blind Denial of Service (DoS) attacks. Despite the availability of existing anomaly detection methods that leverage rule-based systems or traditional machine learning methods, these methods have several limitations, including the need for extensive training data, predefined rules, and limited explainability. Addressing these challenges, we propose a novel anomaly detection framework that leverages the capabilities of Large
Language Models (LLMs) in zero-shot mode with unordered data and short natural
language attack descriptions within the Open
Radio Access Network (O-RAN) architecture. We analyse robustness to
prompt variation, demonstrate the practicality of automating the attack descriptions and show that detection quality relies on the semantic completeness of the description rather than its phrasing or length. We utilise an RRC/NAS
dataset to evaluate the solution and provide an extensive comparison of open-source and proprietary LLM implementations to demonstrate superior performance in attack detection. We further validate the practicality of our framework within O-RAN's real-time constraints, illustrating its potential for detecting other Layer-3 attacks.
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All authors Thusitha Dayaratne, Ngoc Duy Pham, Viet Vo, Shangqi Lai, Sharif Abuadbba, Hajime Suzuki, Xingliang Yuan, Carsten Rudolph