Cryptography and Security
gr-PHYSEC: Real-time Channel-based Key Generation for Physical Layer Secure Wireless Communications
Jose Angel Sanchez Viloria, George Sklivanitis and Dimitris Pados
Securing wireless communication against eavesdropping is critical, particularly in dynamic and decentralized environments. We present gr-PHYSEC, a new GNU
Radio out-of-tree (OOT) module for real-time physical-layer key generation. Unlike traditional key generation that relies on pre-shared secrets or computational complexity, our approach derives symmetric keys from the wireless channel's inherent randomness. We embed a trained neural network within GNU
Radio to extract channel features between trusted parties (Alice and Bob) during probe exchanges. These features are quantized into binary keys, reconciled via Reed-Solomon encoding, and further secured with SHA-512 hashing. The generated keys are then directly used to encrypt data. Real-world experiments at the FAU CAAI connected robotics testbed using ADALM Pluto software-defined
radios and NVIDIA Jetson Orin validate the approach with ground robotic platforms. Results demonstrate low key disagreement rates and strong randomness, as verified by the NIST test suite for random and pseudorandom number generators for cryptographic applications. This integration showcases how GNU
Radio can support real-time AI-driven security solutions, pushing the boundaries of software-defined secure communication. The source code for this project is available at: https://github.com/C2A2-at-Florida-Atlantic-University/gr-PHYSEC
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Cryptography and Security
Illusion of Depth: Revealing Hidden Stereo Vision Vulnerabilities in Depth Estimation
Sri Hrushikesh Varma Bhupathiraju, Tetsu Ishizue, Nicholas U. Costagliola et al. (+4 more)
Stereo cameras are integrated into autonomous systems such as self-driving cars, drones, and
robots to offer precise depth estimation in a cost-effective manner compared to
LiDAR technology. In this work, we reveal an intrinsic vulnerability in stereo cameras that stems from their pixel sampling and calibration processes, which can influence the outputs of stereo matching
algorithms. Attackers can achieve fine-grained control over the estimated depth of real obstacles using simple repeating patterns, without relying on sophisticated
adversarial machine learning techniques. Furthermore, deep learning-based depth estimation models exhibit a similar vulnerability. We evaluate the impact of this attack on two widely used stereo matching
algorithms (BM and SGBM), three deep learning models (PSMNet, MoCha-Stereo, and UniMatch), a stereo-
LiDAR fusion model (SGM-DDC), and two popular commercial stereo cameras, the ZED2 and Intel RealSense D435. For example, in the ZED2 camera, an attacker can displace obstacles up to 20~meters farther or 12~meters closer. In our real-world evaluation in a driving setting, a brief 0.5~second attack can trigger emergency braking in a popular autonomous driving framework. We further demonstrate the feasibility at driving speeds up to 40~km/h using CARLA. Finally, we confirm the ineffectiveness of state-of-the-art defenses, and we propose a novel strategy that leverages similarity scores to dynamically detect and suppress the depth discrepancies. Our work highlights vulnerabilities hidden in stereo matching and deep learning depth estimation models, addressing critical limitations in autonomous system deployments.
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All authors Sri Hrushikesh Varma Bhupathiraju, Tetsu Ishizue, Nicholas U. Costagliola, Ozora Sako, Kentaro Yoshioka, Takeshi Sugawara, Sara Rampazzi
Cryptography and Security
Understanding the Usability of Cryptographic Verification Tools
Tarikul Islam, Yasin Islam, Khandakar Ashrafi Akbar et al. (+1 more)
Cryptographic protocol verification tools are widely used to analyze the security of complex protocols, yet how users interact with these tools remains comparatively understudied. We present an exploratory human-centered study of experienced users of Tamarin, ProVerif, and related protocol verifiers. Our survey included researchers, graduate students, and practitioners with hands-on experience using Tamarin, ProVerif, or related tools. The findings reveal usability barriers across the verification workflow, including difficulties debugging non-termination and performance issues, and the lack of systematic methods for validating formal models against real protocols. When proofs fail without concrete attacks, users commonly simplify models, add helper lemmas, and revisit modeling abstractions. Participants also called for actionable diagnostics, clearer explanations of results, visualization, and automation for recurring proof tasks. Our findings suggest that persistent usability challenges arise from the gap between protocol-level
reasoning and the verifier's formal model, proof procedures, and diagnostic output. We derive concrete design priorities for improving the accessibility, interpretability, and usability of cryptographic protocol verification tools.
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All authors Tarikul Islam, Yasin Islam, Khandakar Ashrafi Akbar, Imtiaz Karim
Cryptography and Security
Exploiting and Securing Docker containers and Kubernetes pods from a MitM attack
Henry Kabuye, Ismail Khalid Kazmi, Chunyan Mu et al. (+1 more)
PURPOSE - Workloads in containers, such as Docker containers and Kubernetes pods, are vulnerable to many of the same attacks as workloads in non-container environments, including phishing, application exploits and network intrusions. This systematic review and design-and-creation study explores techniques for securing containerised-based operating systems against Man-in-the-Middle (MitM) attacks. The proposed framework uses a conceptual model for representing communication and cryptographic primitives, together with the AnBxJ Java security library and container firewalls operating at layer 7 of the OSI model. The study addresses the question: How can containerised-based operating systems be effectively secured from Man-in-the-Middle attacks? It aims to support practitioners in protecting Docker and Kubernetes deployments by systematising security practices and applying a zero trust architecture. METHODOLOGY - The research uses a Systematic Review (SR) based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), bringing together evidence from studies addressing the same research topic. FINDINGS - Success factors were identified, and a security mechanism was successfully implemented in a containerised-based operating system scenario. VALUE - The findings may help practitioners protect Kubernetes and Docker installations by systematising container security practices and providing a zero trust architecture for containerised-based operating systems.
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All authors Henry Kabuye, Ismail Khalid Kazmi, Chunyan Mu, Paolo Modesti
Cryptography and Security
RuleAutoPilot: Synthesizing Deployable Suricata Rules from Network Traffic
Mughees Ur Rehman, Aritran Piplai and Murat Kantarcioglu
Rule-based Intrusion Detection Systems (IDS) such as Suricata are central to network security, yet crafting effective detection rules demands deep expert knowledge and cannot keep pace with emerging threats. Existing LLM-based approaches can reduce analyst effort, but they either rely on curated threat intelligence that is produced only after the underlying traffic artifacts already exist, or they require costly LLM use without sufficient quality control. We present RuleAutoPilot, an end-to-end agentic framework that generates deployable Suricata rules directly from malware network traffic, with no prior threat intelligence required. A key challenge is noise: network traffic captures often contain a small amount of security-relevant traffic mixed with large volumes of background traffic, which reduces LLM
reasoning quality and increases cost. RuleAutoPilot addresses this challenge with a Benign Traffic Fingerprinting stage that removes known benign background flows before LLM processing. Rules that fail syntax checks, do not trigger on the source traffic, or generate false positives on a benign corpus are automatically repaired using structured feedback. Across 1,296 malware PCAPs, execution-grounded verification raises rule quality (F1) from 0.443 to 0.539. On a stratified 200-PCAP subset, RuleAutoPilot on the open-weight gpt-oss-120b reaches near-frontier quality, 0.524 F1 against Claude Opus 5 under Claude Code's 0.623, at 52x lower billed-
token cost. Swapping only the backbone to Claude Opus 5, RuleAutoPilot surpasses Claude Code outright, 0.656 F1 against 0.623, at 40x fewer
tokens. A stronger backbone raises RuleAutoPilot's own ceiling, but at the same backbone, our scaffold still outperforms Claude Code's, showing the scaffold contributes independently of the backbone.
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Cryptography and Security
Analyzing Multi-Factor Authentication Through Cryptographic Security Properties
Ryan Tipping, Yousef Tahboub and Krishna Bodige
Modern authentication systems use cybersecurity techniques to validate the identity of the person (or applications acting on behalf of the person) as a primary defense against unauthorized access. While initially built around single mechanisms such as usernames/passwords, physical
tokens, or biometrics, current systems have evolved into multi-factor authentication (MFA) platforms that combine multiple mechanisms. Among them, several focus on strategies that prevent replay attacks (i.e. the reuse of a component that could have been potentially compromised).
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Cryptography and Security
Feasibility of Homomorphic Inference for a Genomic Foundation Model
Christos Galanopoulos, Kimon Antonios Provatas and Ilias Georgakopoulos-Soares
Human genomic sequences can identify individuals, cannot be replaced after disclosure, and are the inputs that genomic foundation models are designed to interpret. We assess whether a compute provider can execute a released genomic foundation model without receiving query-derived genomic values in plaintext and whether correctness,
memory, or cost prevents complete encrypted inference. We first reproduce the released model on three genomic task families and freeze an independently validated numerical reference. We then implement a client-assisted approximate homomorphic encryption protocol: the provider evaluates linear
algebra on ciphertexts, while the key-holding data owner evaluates exact normalization, causal softmax, and activation functions at fixed boundaries. A noninteractive configuration completes one released-weight block but exceeds the tested accelerator-
memory envelope when configured for composition. The client-assisted configuration executes all released
transformer blocks and the task head for one heldout genomic-signal input at its full
prompt length. It matches the frozen final label, peaks at 9,839 mebibytes of accelerator
memory, and completes in 6,683 seconds on one accelerator. These results establish arithmetic feasibility for a complete classifier, while repeatability, network transport, and private
token-index lookup remain unresolved. The biomedical significance is that, under the stated threat model, a served genomic model can process an encoded sequence without exposing plaintext queryderived activations to the compute provider.
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Cryptography and Security · Cross-listed from cs.LG
Decoy Direction Optimization: A Post-Hoc Defense Against LLM Abliteration
Aashiq Muhamed, Mona T. Diab and Virginia Smith
Safety guardrails in open-weight
language models can be readily bypassed using Refusal Feature Ablation (RFA), a technique that identifies and projects out a linear refusal direction from the residual stream, often achieving a high attack success rate (ASR) while preserving model capability. Defending against these attacks typically requires computationally expensive safety finetuning for every new checkpoint. We introduce Decoy Direction Optimization (DDO), a fast, post-hoc weight-editing defense that requires no base-model finetuning. Our approach is based on a simple mechanistic insight: ablation attacks rely on contrastive
estimators to find the refusal direction. Rather than trying to hide the true refusal circuitry, DDO actively injects a high-magnitude, nonlinear decoy signal into the network's MLP
neurons. When an attacker attempts to locate the refusal direction, the decoy corrupts their
estimator, tricking them into ablating a harmless orthogonal feature while the actual safety mechanism remains intact. We prove a spectral bound formalizing this effect and evaluate DDO across six model families, achieving <10% ASR under standard RFA. On Llama-3-8B-Instruct, DDO remains comparable to trained defenses under adaptive multi-phase attacks (65% vs. 58% worst-case ASR) and reduces Heretic weight-level attack ASR from 88.7% to 18%, all at 30 to 450 times lower optimization cost per configuration than the trained baselines.
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Cryptography and Security
Permutation-Based Stegomalware in Large Language Models: Threats and Countermeasures
Danny Wood and James Stringer
The difficulty of training large
language models (LLMs), together with their ubiquity, raises the threat of stegomalware, where malicious payloads are embedded into model weights. Recent work has demonstrated the use of permutation
symmetry in model weights to mitigate these threats, but failed to show neutralization of stegomalware across all weights for LLMs. In this paper, we demonstrate the full potential of behavior-preserving
symmetries as a defense against stegomalware, as well as the risks these
symmetries pose when exploited by attackers. For stegomalware neutralization, we improve upon previous work, demonstrating that it is possible to select permutations which displace all model parameters. This contrasts with previous methods which left a significant percentage of weights unaltered in LLMs. When used in an attack, we show that permutation
symmetries can encode malware into the weights of a model in a way that is theoretically lossless, requires no retraining after encoding, and needs no payload-specific information in the extraction script—a combination of characteristics not previously seen in any single method. While theoretically lossless, permutation can in practice alter model behavior due to the accumulation of numerical error. We therefore quantify the loss in model performance associated with applying these methods, for both attack and defense, showing it to be minimal.
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Cryptography and Security · Cross-listed from cs.LG
SWB-DM: A Calibrated Sliced-Wasserstein-Barycenter Aggregator with Delayed-Momentum Caching for Byzantine-Robust Federated Learning under Partial Participation
Saranraj S, Saranya M S, Alex David S et al. (+1 more)
Robust aggregation methods for
federated learning quietly rest on a fragile assumption: that whoever shows up in a given round is a fair sample of the full population. In practice, they rarely are. When only a handful of clients participate per round, even a modest fraction of adversaries can dominate that sample and silently invalidate the finite-sample guarantees that coordinate-wise median, Krum, Bulyan, and trimmed mean all depend on. We introduce SWB-DM to address this directly. SWB treats each slice of a client update as a one-dimensional distribution, computes a trimmed Wasserstein barycenter across clients, and recovers coordinate identity via a medoid-based gauge-fixing step – a heuristic we developed and do not claim it belongs to standard optimal-transport theory. DeMoA-style delayed momentum then caches updates across the full client population each round, decoupling robustness from whoever happened to be sampled. Trim ratio calibration is not cosmetic: under-trimming causes collapse at corruption levels a properly calibrated model survives. Across 448 CIFAR-10 configurations, plus CIFAR-100, FEMNIST, and a 500-client scalability run, we find several mechanistically distinct failure modes. Even-sample coordinate-wise median degrades to a deterministic wrong answer. Krum silently violates its own n greater than 2f+2 precondition and diverges without warning. Bulyan's n greater than or equal to 4f+3 threshold produces a sharp pass/fail boundary. On attacks, IPM defeats order-statistic defenses – including SWB – more reliably than ALIE, confirmed through delta-space measurements against a convergence bound. SWB-DM's cache carries a real warm-up cost, but extending all baselines to the same round budget shows its CIFAR-10 gains are disproportionately large. On CIFAR-100, FLTrust benefits more – for reasons entirely unrelated to caching.
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All authors Saranraj S, Saranya M S, Alex David S, Ajay Kumar A
Cryptography and Security
Universal Defenses for Tool-Integrated LLM Agents Against Adversarial Attacks
Xiaoyan Li and Yunli Wang
Large
Language Model (LLM)
agents have demonstrated impressive capabilities across a variety of domains, particularly when integrated with external tools for multi-step task completion. However, they are increasingly vulnerable to
adversarial attacks, including direct
prompt injection, indirect
prompt injection,
memory poisoning, and backdoor attacks, which exploit the model's openness to
prompt injection and tool manipulation. In this work, we explore practical and generalizable defense strategies within a unified framework across these four attack types. We introduce two universal tool-based defenses: Attacker Tool Filtering, which uses anomaly detection (e.g., Isolation Forest) to identify and remove suspicious tools, and Normal Tool Recalling, a white-box method that restores the
agent's original toolset prior to planning. Additionally, we incorporate
prompt-based defenses: Chain-of-Thought prompting and self-reflection techniques to enhance
reasoning and task paraphrasing to mitigate attacks. Experimental results across both four open-source LLMs (Gemma2-9B, Qwen2-7B, LLaMA3-8B, and LLaMA3.1-8B) and three proprietary LLMs (GPT-3.5, GPT-4, and GPT-5) show that our methods significantly reduce the Attack Success Rates (ASR), achieving 0% ASR in many settings, while preserving or even improving the original task success rate. These findings highlight the promise of simple, modular, multi-layered defenses for strengthening the security and robustness of tool-integrated LLM
agents. The code is available at https://github.com/Xiaoyan-Lisa/Defenses-for-Tool-Integrated-LLM-
Agents-Against-
Adversarial-Attacks.
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Cryptography and Security · Cross-listed from cs.CL
RAG-CT: Mitigating Privacy Risks on Retrieval-Augmented Generation Systems via Scanning Prompt Distribution
Xingyu Lyu, Jiayimei Wang, Jianfeng He et al. (+3 more)
Retrieval-Augmented Generation (RAG) has emerged as a powerful paradigm for improving the quality of generated contents of Large
Language Models (LLMs) by grounding responses in external knowledge, thus reducing
hallucinations and factual errors. However, recent studies have highlighted a critical vulnerability: adversaries can exploit the
retrieval process to extract personally identifiable information (PII) from the underlying corpus. To mitigate this risk, we propose a novel defense, RAG-CT, that identifies malicious queries by analyzing their
entropy and margin distributions and using a score-based detection method. Extensive experiments with four state-of-the-art attack strategies and four defense baselines on two
datasets show that our approach significantly reduces PII leakage while outperforming existing defenses. This work provides a lightweight yet effective mechanism to protect RAG systems against PII leakage without requiring modifications to the underlying LLM or retriever.
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All authors Xingyu Lyu, Jiayimei Wang, Jianfeng He, Ning Wang, Yidan Hu, Yimin Chen
Cryptography and Security
Adversarial Testing of Automated Program Repair Agents for Security Vulnerabilities
Fares Trad, Simin Chen, Hung Viet Pham et al. (+2 more)
Software
agents with Large
Language Models (LLMs) are designed for Automated Program Repair (APR) tasks, raising the possibility that, in the near future, APR
agents will fix bugs automatically without much human intervention. Can we trust an APR
agent to produce both functionally correct and secure code in such situations? What if attackers target production APR
agents with
adversarial issues that seem benign but may influence the
agents to produce correct but insecure code? In this paper, we took a first step towards answering these questions by conducting an empirical study. First, we created SWEADV, a
benchmark of 750
adversarial issue descriptions constructed from 150 repair tasks in SWE-bench Verified. For each repair task, we created five
adversarial issue descriptions, one for each attack type: command execution, deserialization, path traversal, denial of service, and weak hashing. Second, we evaluated mini_swe APR
agents from three LLM backends on SWEADV: GPT-5-Mini, MiniMax-M2.5, and DeepSeek-R. We found that on average,
adversarial issue descriptions can induce malicious behaviors with successful repair in 51.7% of cases. Third, we investigated whether typical detection mechanisms are sufficient to prevent such malicious patches from being accepted. Pre-repair detection with LLM-as-judge on the
adversarial issue descriptions resulted in an average detection accuracy of only 62.3%. Post-repair detection on
adversarial APR patches using static analysis tools and LLM-as-judge achieved average detection accuracies of only 39.4% and 55.4%, respectively. We conclude that autonomous APR
agents cannot be trusted yet in production deployment, given their susceptibility to
adversarial attacks.
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All authors Fares Trad, Simin Chen, Hung Viet Pham, Gias Uddin, Baishakhi Ray
Cryptography and Security
Vulnerability Localization Benchmark: Measuring Agentic Security Analysis at Repository Scale
Aman Priyanshu, Supriti Vijay, Kimia Majd et al. (+8 more)
Language-model
agents increasingly operate over complete software repositories, yet cybersecurity evaluations primarily measure whether they can detect, reproduce, or repair vulnerabilities rather than whether they can locate the relevant code. We study vulnerability localization: given a weakness class and an unfamiliar repository, identify the implementation files associated with that weakness. We introduce the Vulnerability Localization
Benchmark (VLoc Bench), comprising 500 real world vulnerabilities from 290 repositories across six package ecosystems and 147 CWE categories. Each task pairs repository snapshots immediately before and after a security fix. On the vulnerable snapshot, an
agent receives only the CWE description and read-only terminal access and must return the affected files; on the patched snapshot, it must determine that the recorded vulnerability is no longer present. We evaluate 27
language models and four static-analysis tools under a common
agent interface. Repository-scale vulnerability localization remains difficult: the strongest system achieves 0.229 File F1, and 38.4% of tasks receive no correct localization from any evaluated model. We further find that stronger localization does not imply reliable behavior after remediation: systems that identify vulnerable files effectively can still report unsupported locations on patched repositories. These results establish vulnerability localization as a distinct repository-scale capability and provide a setting for studying both how security
agents search for vulnerable code and when they should refrain from reporting it.
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All authors Aman Priyanshu, Supriti Vijay, Kimia Majd, Xuhong He, Fraser Burch, Takahiro Matsumoto, Jianliang He, Baturay Saglam, Arthur Goldblatt, Zhuoran Yang, Amin Karbasi
Cryptography and Security
Authorization Architectures for Tool-Using AI Agents
Rakesh Kumar Surapani, Pradeep Kumar Dolabehera Kakitapelli, Arun Morampudi et al. (+1 more)
Tool-using artificial intelligence (AI)
agents, systems that autonomously invoke application programming interfaces (APIs), databases, browsers, and inter-
agent protocols such as the Model Context Protocol (MCP), are becoming production infrastructure. Yet the security model governing when an
agent is authorized to act on a human's behalf remains underdeveloped. Trustworthy human-AI systems require that every consequential
agent action be traceable to a human principal, bounded by what that human actually delegated, and contestable after the fact; few documented deployments satisfy all three properties reliably and end to end. Existing literature addresses fragments of this problem in isolation, credential management for non-human identities, classical access control models,
prompt injection, and audit trails, while giving little
attention to the authorization decision point itself, the moment a tool invocation occurs, and mechanisms that make that decision correct, enforceable, and accountable. This review introduces a principal hierarchy spanning human user, operator/deployer, orchestrator
agent, sub-
agent, and tool endpoint as an organizing framework, and examines five interdependent layers:
agent identity and credential lifecycle; delegation and scope propagation across multi-hop chains; runtime enforcement and just-in-time authorization at policy enforcement points (PEPs);
prompt injection as an authorization bypass that breaks the principal hierarchy; and auditability, provenance, and non-repudiation. Drawing on a structured narrative review of 89 primary sources screened from approximately 180 candidates published between 2023 and 2026, we propose seven structural requirements, derive a four-layer reference architecture, apply the requirements to three deployable reference configurations, and identify runtime enforcement and aggregation bounds as the principal unresolved gaps.
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All authors Rakesh Kumar Surapani, Pradeep Kumar Dolabehera Kakitapelli, Arun Morampudi, Praveena Padi
Cryptography and Security
The Model Proposes, the Code Disposes: A Pre-Registered Ablation of a Verifier-and-Acceptance Stage in an LLM-Orchestrated Offensive-Security Agent
Theodoros Moutesidis
We evaluate whether a verifier-and-acceptance stage - a model verifier whose verdicts are enforced by deterministic code - changes what an LLM-driven offensive-security
agent reports. We report a 15-run exploratory pilot, a pre-registered 20-run confirmatory ablation, and a pre-registered 2 x 2 factorial study with 40 runs across two deliberately vulnerable lab targets. In the confirmatory study, removing the stage eliminated pre-report suppression (median 2 versus 0 findings per run; exact one-sided p = 0.00003) and reduced model-blinded shipped precision (median 0.471 versus 0.353; p = 0.0087). Recall against a frozen but incomplete ground-truth list did not differ significantly (two-sided p = 0.158; equivalence was not established). The factorial study attributed suppression to the model verifier (Holm-adjusted p = 0.004); deterministic acceptance rules alone suppressed no false positives, and no interaction was detected (p = 0.72). The full design retained 93.8% of model-adjudicated true candidates but did not meet its pre-registered non-inferiority criterion because the lower one-sided 95% bound was 0.875, below the 0.90 floor. Across the confirmatory and factorial studies, an instrumented canary recorded zero contacts in 60 of 60 runs, with incidental external contacts disclosed separately. Independent human adjudication of the retained blind packets is pending, so precision and sensitivity endpoints are supporting rather than final evidence. Six audit-trail failures, including one in the evaluation tooling, are also disclosed. The results support a narrow conclusion: the verifier changes what the system ships, while deterministic code supplies enforcement and auditability; they do not establish superiority to other
agents or generalization beyond lab targets.
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Cryptography and Security · Cross-listed from cs.IT
Private Information Retrieval With Arbitrary Privacy Requirements: Introduction and Capacity Results
Mohamed Nomeir, Shreya Meel and Sennur Ulukus
In this paper, we introduce the problem of private information
retrieval (PIR) under arbitrary
privacy requirements, in a graph-based storage system. This formulation is motivated by the server storage limitations, abundance of data (messages) and heterogeneous data
privacy requirements. Under the arbitrary
privacy requirement, each message has to be retrieved privately from a pre-specified subset of servers, where the subset always includes the servers storing it. Thus, each server is associated with a
privacy set, which pre-specifies the message indices that should be privately retrieved from it. This setting is a generalization of the classical PIR setting, where the required message index needs to be kept private from all servers, i.e., there, the
privacy set of each server comprises all message indices. Our setting is also a bridge between the newly formulated local PIR (LPIR) setting and the classical PIR setting, where in the former, the
privacy set is exactly the set of stored message indices. In this paper, we derive general lower and upper bounds on the PIR capacity for general graphs, under certain
privacy requirements, that capture the essence of both LPIR and classical PIR. Then, we focus on path and cyclic storage graphs under these and more fine-grained settings, for which we derive capacity results for certain cases, and establish lower and upper bounds for others. Their low degree allows for a more in-depth understanding of the new
privacy formulation and admits more
privacy requirement settings compared to other simple graphs. Finally, we introduce a new graph structure, the pyramid storage graph, to model server storage. Although this graph has never been investigated in the literature in any PIR context, it enjoys a nice symmetric structure for message storage and replication patterns.
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Cryptography and Security · Cross-listed from cs.LG
LLM-Based Schema-Aware Split Learning for Privacy-Preserving Mental Distress Prediction Across Heterogeneous Surveys
Md Khalid Syfullah and Alvi Ataur Khalil
Rising societal and lifestyle complexity has been linked to a growing prevalence of mental distress worldwide. Educational institutions, workplaces, clinics, etc. collect large volumes of mental health survey data to understand and reduce this burden. Collaborative analysis of such data could yield effective generalizable predictive models.
Privacy constraints and varied survey designs (i.e., different questions, scales, and formats) hinder direct integration. We propose a schema-aware split learning (SL) framework that preserves
privacy, using a large
language model (LLM) as a shared semantic encoder to harmonize heterogeneous survey schemas across institutions. We serialize each survey record into a natural-
language description, unifying disparate survey schemas into a common format. The LLM is fine-tuned for mental distress assessment via Low-Rank Adaptation (LoRA) and partitioned across client and server. Clients retain the raw survey responses locally and run only a lightweight front-end, so original records never leave the institution that collected them. The resource-intensive backbone runs on the server, minimizing client-side computation. Using LLaMA-3.2-3B-Instruct, the framework attains an average ANLS of 0.708 with only 2,000 training samples, surpasses
federated learning (FL) in eight of nine settings, and cuts per-client computation by three orders of magnitude, while generalizing to unseen
datasets. Overall, it enables accurate,
privacy-preserving, and resource-efficient collaborative learning from heterogeneous mental health survey data.
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Cryptography and Security · Cross-listed from quant-ph
Instantiating Microcrypt: Obstacles and opportunities via tailored state certification
Jose Carrasco, Jens Eisert, Soumik Ghosh et al. (+3 more)
Recent work has introduced the
Hamiltonian phase state (HPS) assumptions, which postulate that
Hamiltonian phase states can be used to instantiate pseudorandom and one-way state generators. Additionally, it has been conjectured that these assumptions can be true, even if one-way functions do not exist. This is exciting, because if true, then the HPS assumptions provide a route to the instantiation of Microcrypt. In this work we falsify this
conjecture, by proving that if the HPS assumptions are true, then one-way functions exist. While this removes the possibility of instantiating genuine Microcrypt cryptography with
Hamiltonian phase states, it shows that the HPS assumptions provide novel inherently
quantum assumptions for the construction of classical cryptography. Technically we achieve this via a method for the construction of one-way puzzles from one-way state generators and tailored "measure first, ask later" state certification protocols. This generalizes prior constructions of one-way puzzles from one-way state generators via classical shadows and allows us to relate properties of the one-way puzzle to properties of the state certification protocol used in the construction. Specifically, if the state certification protocol admits efficient classical post-processing then one obtains an efficiently verifiable one-way puzzle, and if the state certification protocol can be efficiently classically simulated in a certain sense, then one obtains a classical one-way puzzle, which implies one-way functions. The latter observation allows us to prove that the HPS assumptions imply one-way functions, by exploiting properties of state certification protocols for phase states. The former observation provides a new toolbox for the construction of efficiently verifiable one-way puzzles by exploiting tailored state certification protocols for pseudorandom and one-way state generators.
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All authors Jose Carrasco, Jens Eisert, Soumik Ghosh, Dominik Hangleiter, Nicky Kai Hong Li, Ryan Sweke
Cryptography and Security
First Galileo SAS Authenticated Time Solution
Aleix Galan-Figueras, Ignacio Fernandez-Hernandez, Wim De Wilde et al. (+5 more)
Spoofing attacks against civilian GNSS receivers have grown more common, especially near conflict zones where they now disrupt civil aviation, maritime operations, and critical infrastructure on a daily basis. Spoofing is possible because legacy civil GNSS signals are largely predictable in both their navigation data and ranging codes, allowing an attacker to forge a signal that imposes a false position and time on an unsuspecting receiver. Cryptographic authentication schemes such as Galileo's Open Service Navigation Message Authentication (OSNMA) mitigate this threat by verifying the authenticity of the navigation data. The ranging code itself, however, remains unprotected. To close this gap, Galileo is introducing a Signal Authentication Service (SAS) in the E6-C signal, which directly authenticates ranging measurements. SAS is currently transmitted by only two satellites in an elliptical orbital plane, of which at most one is visible at a time, meaning a full position solution is not yet possible; however, a georeferenced receiver can still obtain an authenticated time solution. This paper presents, to the authors' knowledge, for the first time, a timing solution computed from an authenticated civil GNSS signal. We develop a snapshot software receiver implementing a simplified version of the Galileo SAS protocol to compute the receiver clock bias from an authenticated pseudorange, using
radio-frequency data recorded with an engineering prototype software-defined
radio receiver from Septentrio. We evaluate the resulting timing solution using recordings from both SAS-capable satellites collected at different locations, demonstrating the feasibility of authenticated timing ahead of full SAS operational deployment.
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All authors Aleix Galan-Figueras, Ignacio Fernandez-Hernandez, Wim De Wilde, Rafael Terris-Gallego, Gonzalo Seco-Granados, Cillian O'Driscoll, Sibren De Bast, Sofie Pollin
Cryptography and Security
RAPID: A Real-Time Defense Against Unauthorized Model Distillation for Text-to-Image Services
Zihan Wang, Boheng Li, Rui Zhang et al. (+5 more)
Diffusion-based text-to-image (T2I) models are increasingly used for visual content creation, making their generation capability a valuable intellectual property asset. However, this capability is vulnerable to black-box output-based
distillation, where an adversary queries the service, collects
prompt-image pairs, and trains an unauthorized substitute model that mimics its generation behavior. Existing perturbation-based defenses apply sample-wise optimization to make generated images disruptive to unauthorized training, but introduce substantial computation and latency that reduce the usability of online T2I services. A natural solution is to integrate defensive perturbations into the VAE decoder, allowing the protected model to generate defended images directly without online sample-wise optimization. However, existing sample-wise objectives struggle to transfer to the shared decoder setting. We empirically find that a defensive shared decoder induces a substantially smaller latent shift than sample-wise optimization, suggesting that objective reachability matters more than destructiveness in this setting. To overcome this limitation, we propose RAPID, a self-referenced latent maximization framework that removes external dependencies and encourages the same model update to induce consistently disruptive effects across training samples, thereby improving reachability. We further introduce reconstruction-guided color regularization that blocks the latent shortcut and reinforces visual disruption. Extensive experiments on four T2I models and four
datasets, with comparisons against five representative baselines, show that RAPID consistently degrades substitute-model generation quality while preserving service visual fidelity. Our work establishes a paradigm for real-time protection against unauthorized
distillation in deployed T2I systems.
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All authors Zihan Wang, Boheng Li, Rui Zhang, Wenshu Fan, Qingchuan Zhao, Tianwei Zhang, Hongwei Li, Guowen Xu
Cryptography and Security
When the World Lies: Backdoor Attacks on Latent World Models for Downstream Control
Roberto Riaño, Gorka Abad, Stjepan Picek et al. (+1 more)
Pretrained world models, learned simulators that encode an observation into a latent state and predict how it evolves under actions, are beginning to be reused as off-the-shelf dynamics backbones for control, like pretrained encoders and
language models are reused today. We show that this reuse opens a supply-chain backdoor: an adversary who controls only a released checkpoint can hijack the downstream controller, even though the victim trains and evaluates entirely on clean data and never sees the trigger. The attack encodes no explicit trigger-to-action rule. Instead, the poisoned model routes trigger-bearing observations into a chosen latent region and reshapes the local dynamics there, so that the victim's own optimization (Dreamer-style actor training in imagination, or MPC/CEM planning over predicted futures) re-discovers the attacker's target action on its own. Across several control tasks and trigger families, the trigger steers the controller's action toward the attacker's target, controlling every action dimension and hijacking 100% of triggered steps on the strongest settings. The checkpoint still passes the clean-data diagnostics a victim would run before deployment, with clean-task success retaining at least $\sim$75%. The effect is temporally gated: it appears only while the trigger is present and disappears when the trigger is removed. Trigger-blind repair is budget-dependent: moderate clean fine-tuning can preserve clean utility while leaving the triggered failure intact, whereas sufficiently aggressive adaptation can remove it only after substantially degrading clean control. The world-model backbone itself is therefore an emerging and underexamined attack surface for control. The full code and artifacts are available in our repository.
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All authors Roberto Riaño, Gorka Abad, Stjepan Picek, Aitor Urbieta
Cryptography and Security · Cross-listed from cs.NE
Event-Native Symbolic-Temporal Spike Encoding Framework for Heterogeneous Cyber Streams
Dalton Diez, Peyton Andras, Max Shroyer et al. (+1 more)
Spiking neural networks (SNNs) have shown promise for sparse, event-driven computation through stateful processing that is naturally compatible with low-power edge hardware. These properties align with cyber monitoring, where data arrives asynchronously, and malicious behavior often emerges through temporal patterns across event sequences. However, cyber streams are not composed solely of continuous numeric signals: their informative structure is also carried by categorical identifiers, irregular timing, and local behavioral context. Traditional rate- and population-based spike encodings are not naturally suited to these heterogeneous semantics, while conventional intrusion detection system (IDS) pipelines typically resolve the mismatch by converting raw events into flows, fixed aggregation windows, or dense tensors. Although useful for conventional classifiers, these transformations introduce buffering latency, obscure native temporal structure, and weaken the computational advantages of event-driven neuromorphic processing. We introduce an event-native symbolic-temporal spike encoding framework that maps heterogeneous cyber events directly into sparse, spike-compatible inputs. By assigning encoding roles to semantic identity, local frequency context, and inter-event timing, the framework preserves categorical semantics and temporal dynamics. We validate the approach on packet-level Network IDS and extend it to message-level CAN IDS, using both domains to evaluate whether the encoding exposes usable structure for recurrent SNNs operating directly on native event streams. Under edge-oriented, $\mu$Caspian-aligned hardware constraints, compact recurrent SNNs achieve strong anomaly detection performance, with an operational hybrid metric ($J_{hybrid}$) of 0.987 on Network IDS and 0.980 on CAN IDS.
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All authors Dalton Diez, Peyton Andras, Max Shroyer, James Ghawaly Jr
Cryptography and Security
HYDRA: Quantifying Botnet Resource Thresholds for Efficient Link-Flooding Attacks on LEO Satellite Networks
Roee Idan, Rami Puzis, Asaf Shabtai et al. (+1 more)
Low Earth orbit (LEO) satellite constellations, such as Starlink and Kuiper, are rapidly emerging as a critical backbone for low-latency global connectivity. As these systems expand, they become more attractive attack targets, necessitating increased resilience and security. Threat actors seek to exploit constellation-specific properties such as predictable motion, time-varying
topologies, and reliance on inter-satellite and ground-satellite links. Recent work has shown that link-flooding attacks (LFAs) can exploit these properties to congest strategic network bottlenecks. Yet, prior work does not quantify the resilience of LEO networks to targeted disruption. We present HYDRA, a modeling and optimization framework that formulates LFA variants as botnet minimization problems. HYDRA quantifies network resilience to LFAs by measuring the smallest active subset of bots and the corresponding traffic allocation required to disrupt communication between targeted geographic areas. Under matched stealth constraints, HYDRA achieves the same targeted disruption as ICARUS while using 34% fewer bots and 23% less aggregate attack traffic. HYDRA achieves over 97% success in sustaining continuous attacks as the network
topology evolves. Finally, HYDRA evaluates five mitigation strategies, showing how routing diversification, ingress policing, distance-based traffic constraints, source throttling, and botnet attrition reduce attack success and improve network resilience to targeted disruption.
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All authors Roee Idan, Rami Puzis, Asaf Shabtai, Yuval Elovici
Cryptography and Security · Cross-listed from cs.CV
Don't Send What You Don't Need: Question-Guided Token Pruning as a Privacy Defense for Vision-Language Models
Md Khalid Syfullah and Alvi Ataur Khalil
Visual Question Answering (VQA) with
Vision-
Language Models (VLMs) is increasingly used in
privacy-sensitive and bandwidth-constrained settings.
Federated Learning (FL), Split Learning (SL), and U-Shaped Split Learning (USL) keep raw data local, but transmitting all visual
tokens across a model partition remains costly and can expose private information. We propose QPriv-VL, a question-guided,
privacy-aware
token-
pruning framework for FL, SL, and USL that prunes visual
tokens before transmission based on task utility and
privacy sensitivity. Its core component is a lightweight Dynamic Threshold Predictor (DTP) that jointly estimates a sample-specific
pruning ratio and a
token-level retention mask in one forward pass. DTP combines question relevance, computed from cross-modal similarity between visual patches and the pooled question
embedding, with a sensitivity signal derived from frozen DINOv2 features. This allows the model to suppress potentially sensitive regions while preserving patches useful for answering the question, without requiring sensitivity labels. We evaluate QPriv-VL on GQA, OK-VQA, VQAv2, SLAKE, VQA-RAD, and PathVQA against four
privacy attack families: FSHA, FORA, iDLG, and attribute-inference membership inference attacks. DTP matches or outperforms fixed-ratio
pruning while using substantially fewer transmitted
tokens. On VQA-RAD, it reduces membership-inference attack success from 0.99 to 0.76-0.79, lowers FSHA and FORA reconstruction PSNR relative to fixed-ratio
pruning, and preserves competitive VQA accuracy using about 40% of the original visual-
token budget. A sensitivity exclusion ratio of 1.20 +/- 0.18 indicates preferential removal of
privacy-sensitive patches, while explainability analysis shows that retention adapts to question semantics rather than generic visual saliency.
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Cryptography and Security
CiteShade: Citation Laundering in Multi-Source Retrieval-Augmented Generation and Its Counterfactual Defense
Guo Fuzheng
Retrieval-augmented generation (RAG) grounds a
language model's answers on retrieved external knowledge and returns each answer with citations that identify its sources. Those citations are the user's audit trail: they let a reader verify a claim without trusting the model. Prior security work on RAG asks whether an attacker can corrupt the answer, leaving the citation channel unexplored. We show that this channel is a new and practical attack surface. We propose CiteShade, the first citation laundering attack to RAG, in which an attacker controlling a single source induces a model to produce an attacker-chosen wrong answer and to attribute it to a trusted source that does not support it, while the evidence for the correct answer remains in context. We formulate the attack as an optimization problem, derive three necessary conditions (
retrieval, generation, and citation) and construct sources satisfying them without any instruction. On multi-source multi-hop question answering the attack raises the wrong-answer rate from 0.01 to 0.68, and source deletion confirms the malicious source is the causal driver in every measured case. Vulnerability tracks a model's propensity to cite rather than its scale, reaching CLR 0.84 under explicit instruction and 0.64 with no instruction at all on the most citation-prone model tested. We then show that perplexity filtering and citation-support checking are each insufficient, and propose a counterfactual defense that verifies which source actually drove the answer.
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Cryptography and Security
Scaling Verification of Cryptographic Software with Aeneas, Rust, and Lean
Son Ho, Cédric Fournet, Jonathan Protzenko et al. (+7 more)
We develop a new methodology for verifying cryptographic software. We target production code written in Rust for performance and system integration, rather than verification convenience. Rust's ownership discipline enables Aeneas to extract a pure model of this code in Lean, relieving us from low-level
reasoning about pointer liveness and aliasing. Lean's extensibility lets us develop tactics and libraries that greatly simplify
reasoning about extracted Rust code. We design and tune our toolchain to facilitate the use of AI.
Agents autonomously write formal proofs, which are independently verified by the Lean kernel.
Agents also assist in the formalization of cryptographic standards and platform-specific intrinsics, which still requires expert design and review. We apply our methodology to SymCrypt, Microsoft's cryptographic provider. We verify its implementations of
algorithms such as SHA-3 and ML-KEM, which were ported from C to Rust. We also extend SymCrypt with experimental optimizations and implementations of
algorithms such as FrodoKEM, ML-DSA, and HPKE to explore the scalability of writing, adapting, and verifying cryptographic code. Our 237~KLOC Lean development establishes safety, panic-freedom, and functional correctness of 16.7~KLOC of Rust code supporting post-
quantum cipher suites for x86-64 and ARM platforms. Our evaluation shows that verified Rust can meet SymCrypt's performance, portability, deployment, and maintainability requirements.
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All authors Son Ho, Cédric Fournet, Jonathan Protzenko, Michael Naehrig, Joshua Clune, Patrick Longa, Guillaume Boisseau, Fernando Leal Sánchez, Aymeric Fromherz, Antoine Delignat-Lavaud
Cryptography and Security
Tractable Defense against Advanced Persistent Threats in Networked Settings
Brandon Collins, Keith Paarporn, Shouhuai Xu et al. (+1 more)
Recently, the theory of Boolean Dynamical Systems was proposed to study the decision theory surrounding the defense of computer networks against Advanced Persistent Threats (APTs). Boolean Dynamical Systems naturally capture four first principle primitives of APTs: the stealthy nature of attacks, limited and noisy information from automated systems like intrusion detection systems, lateral movement after the attacker penetrates into the network, and the defender's ability to secure a subset of computers at any time at the loss of resources such as system uptime. Currently, doing optimal/heuristic control in a computationally tractable manner is not possible because the emergent value function is computationally intractable (with respect to the network size). To resolve this, we propose a mean-field analysis inspired heuristic value function. We prove that our proposed heuristic is based on an exact computation of the value function under the assumption that the underlying state estimate distribution maximizes
entropy. We numerically evaluate the quality of our heuristic as parameterized by the degree to which the
entropy assumptions are violated.
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All authors Brandon Collins, Keith Paarporn, Shouhuai Xu, Philip N. Brown
Cryptography and Security
Approval Integrity and Recovery in LLM Answer Publication
Faruk Alpay and Taylan Alpay
Publication integrity in LLM systems requires binding approved content to its current authorization context. We examine exact-content binding, authorization freshness and checkpoint recovery in Lightcap's publication enforcement mechanism. On 900 independently human-annotated RAGTruth responses from 150 source tasks, three dated Ministral models and a same-model direct-grounding baseline yield 3,600 assessments. The production response-act checker instantiated with 14B accepts 291 of 302 unsupported-labelled answers; the direct baseline accepts 41. Supported-answer retention is 95.2% and 66.9%, respectively. An exact promotion-correction identity tracks error through 100 chronological 3B-14B-8B-14B answer trajectories. Among 65 initially approved answers, the final stateful recheck-recovery policy increases exact-match error by 9.23 percentage points relative to the initial checkpoint (95% article-clustered interval [-1.72, 19.61]). Controlled evidence-fingerprint changes expose asymmetric freshness enforcement between publication and recovery. A separate BIPIA
prompt-injection experiment records zero target insertions among 266 valid editor outputs. External Hugging Face calibration experiments transfer
retrieval models from ArguAna to SciFact and NFCorpus, and diagnostic decision rules from Thunderbird to BGL, distinguishing probability calibration from ranking changes. The measurements separate semantic false approval, stale authorization and recovery-induced error at executable publication boundaries.
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Cryptography and Security
Automating Attack Graph Construction for Agentic Pentesting. Towards Neuro-Symbolic Vulnerability Hunting
Oliver Stevanovic and Jasmin Wachter
Logic attack graphs grounded in scanner output provide explicit and auditable attack path
reasoning LLM-based
agents lack. Integrating symbolic frameworks such as MulVAL to contemporary security workflows or agentic pipelines, however, requires translating scanner evidence to initial facts, and creating domain-specific rules. We present a semi-automated pipeline that addresses this interoperability problem and depict its feasibility in a web-security case study. Our pipeline parses findings from Trivy, Semgrep, and Nmap into MulVAL predicates and uses an LLM-assisted process to construct domain-specific Datalog rules linking scanner-detectable evidence to attack techniques. MulVAL/XSB then performs symbolic inference to generate structured attack paths. We evaluate the attack-graph construction infrastructure on 54 web Capture-the-Flag tasks from CyBench within an agentic pipeline (Hybrid Reasoner); we do not evaluate the performance of the downstream
agent. Every task produced at least one goal-reaching graph, and we achieve mean ground-truth vulnerability coverage of 53.7%, with 51.9% achieving full coverage; mean noise-path rate was 83.9%. With median end-to-end time of 24.9 s (MulVAL
reasoning: 2.7 s) the pipeline is feasible and runtime-practical for agentic workflows, but predicate coverage, rule coverage, and path precision remain limiting factors. Next steps include semantic rule validation and
agent-level comparison for graph-guided pentesting.
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