Cryptography and Security
Context-Aware Operational Security for Autonomous Drones
Burak Tufekci and Cihan Tunc
Autonomous drone-based services have been gaining significant interest across various application domains due to their mobility, flexibility, cost-effectiveness, and capability to integrate various sensors and actuators. However, operational failures or cyberattacks targeting drone systems can lead to severe economic impacts and safety concerns. Hence, ensuring secure and reliable autonomous drone operations is essential for the safe deployment of drone-enabled services. Nevertheless, the traditional security measures fall short due to drones' limited computational resources and power budget (battery), as well as the temporal and sequential behavior of drone operations due to drones' mobile nature. In this paper, we address this gap by utilizing Recurrent Neural Networks (RNNs), specifically focusing on Long Short-Term
Memory (LSTM) networks, for autonomous drone operation security and reliability due to their temporal and sequential analysis capabilities. We leverage these capabilities for anomaly detection in autonomous drone sensor data and operation commands, which we refer to as Denial of Usage Detection Engine IDS (DUDE-IDS). We integrated the proposed DUDE-IDS into the drone mission computer (i.e., operating directly on drones rather than an edge node or ground control stations) to monitor data flows and to detect potential threats in real-time. Extensive experimental results demonstrate the effectiveness of this approach in identifying anomalies associated with GPS spoofing, Man-in-the-Middle (MITM), replay, and Denial-of-Service (DoS) attacks with 98% accuracy. We also evaluate our resource utilization and power consumption under different configurations, demonstrating the applicability of our approach in active drone operations in real-time.
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Cryptography and Security
Measuring and Evaluating the Performance of Generative AI Models for Scam Detection
Cem Topcuoglu, Seyed Ali Akhavani, Harel Berger et al. (+5 more)
Online scams continue to cause substantial financial and personal harm. As a result, detection systems based on Large
Language Models (LLMs) have been integrated into security products ranging from email gateways and browser extensions to fraud-monitoring dashboards. As this adoption accelerates, a common belief has taken hold: that these models are broadly suitable for scam detection. In this work, we investigate whether LLMs, with their strong capabilities in understanding intent, context, and
reasoning, can effectively detect scams across diverse scenarios without task-specific fine-tuning. We curate and release a unique
benchmark dataset of real-world scams spanning multiple formats and topics. We evaluate nine LLMs of varying sizes and architectures, examining their performance under different prompting strategies and comparing them to a fine-tuned BERT-based classifier. Our results show that while larger LLMs generally outperform smaller ones, effective prompting substantially boosts the performance of smaller models. Moreover, LLMs are better at generalizing to unseen scams compared to fine-tuned models, suggesting that pre-trained knowledge contributes meaningfully to scam detection. We release our
dataset and evaluation framework to facilitate future research in robust scam detection using
language models.
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All authors Cem Topcuoglu, Seyed Ali Akhavani, Harel Berger, Sadia Afroz, Michalis Pachilakis, Vibhor Sehgal, Leyla Bilge, Engin Kirda
Cryptography and Security
Physical Time-Lock Puzzles
Niloufar Sayadi, Chenglu Jin, Phuong Ha Nguyen et al. (+2 more)
Traditional time-lock puzzles enforce delayed access to encrypted secrets by relying on inherently sequential computational steps. However, since software-based constructions impose no fundamental bound on the physical execution speed of individual steps, they remain vulnerable to hardware acceleration and improved implementations. In practice, this renders existing schemes “step-lock” rather than true “time-lock” puzzles, making long-term delay guarantees highly speculative against decades of unpredictable hardware advancement. To address this fundamental limitation, we introduce the Physical Time-Lock Puzzle (P-TLP), a new paradigm that anchors solving delay directly to the intrinsic, hardware-bounded evaluation latency of silicon hardware. By leveraging noisy Physical Unclonable Functions (PUFs) as non-parallelizable delay oracles, P-TLPs establish resistance against both parallel computation and algorithmic acceleration under the random oracle model. To tolerate PUF evaluation noise while maintaining a tightly concentrated and predictable solving-delay window, we propose a composite puzzle architecture that combines multiple independent basic puzzles. We formally prove the optimality of a sequential greedy solving strategy and derive tightly concentrated solving-delay windows using Hoeffding and Berry-Esseen bounds. We additionally prove early-solve hardness, establishing that adversaries with substantial classical computation budgets cannot bypass the physically-enforced PUF evaluation bottleneck. We validate our theoretical analysis with an FPGA prototype built around a configurable Ring Oscillator PUF, confirming that our analytical delay predictions tightly match empirical measurements. Our results demonstrate that P-TLPs can deliver highly predictable, long-term delay guarantees, enabling practical deployment in high-value applications such as digital legacy management.
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All authors Niloufar Sayadi, Chenglu Jin, Phuong Ha Nguyen, Zheng Yang, Marten van Dijk
Cryptography and Security · Cross-listed from cs.AI
Learning-Driven Adaptive Audit Scheduling: A Sequential Decision Approach to Off-Chain Data Integrity
Changting Lin, Fan Li, Weihang Yu et al. (+4 more)
We model cryptographic auditing of off-chain data as a Constrained MDP (CMDP) under partial observability: the storage node's hidden type and corruption state make the problem a POMDP, while a miss-rate ceiling rho imposes an explicit security constraint. We propose DRQN-CMDP, a Deep Recurrent Q-Network whose GRU layer maintains a belief over the latent node type, paired with Lagrangian dual ascent that adapts the miss-rate penalty lambda automatically. A pairing-free homomorphic-MAC primitive supplies O(1) on-chain verification cost. Across 13 methods–four DQN variants, PPO, A2C, PPO-Lagrangian, a stateful
Bayesian heuristic, three fixed-rule baselines, and an oracle-informed heuristic–DRQN-CMDP achieves a favourable balance: 83% lower gas than fixed high-frequency auditing, single-digit miss rate (7.5%), and moderate detection latency–a combination no other method matches across all three objectives simultaneously.
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All authors Changting Lin, Fan Li, Weihang Yu, Keyang He, Mingyuan Yan, Yourong Chen, Meng Han
Cryptography and Security
Between Safe Boundaries: Exploiting Temporal Consistency for Jailbreaking Text-To-Video Generation Models
Xingkai Peng, Jun Jiang, Jiayang Liu et al. (+2 more)
Recently, text-to-
video (T2V) models have been widely deployed, sparking growing concerns over their robustness against jailbreak attacks. Existing jailbreak methods, mostly adapted from text-to-image attacks, suffer notable drawbacks when applied to T2V systems. They fail to fully leverage temporal consistency, an inherent characteristic of
video generation. Besides, these methods demand heavy
video query optimization, which is infeasible in practical black-box scenarios. Their
adversarial prompt search is also driven by heuristic local signals, lacking principled structured exploration strategies. To tackle these limitations, we propose BSB, a structured, query-efficient jailbreak framework for T2V models. BSB harnesses temporal consistency by encoding harmful intent as the transition between two individually harmless boundary states. Under this paradigm, the attack targets boundary-state pairs whose interpolation tends to produce unsafe intermediate frames during
video generation. Directly evaluating all candidate pairs within the
video space incurs prohibitive computation cost. Instead, BSB conducts Monte Carlo Tree Search (MCTS) in a cheaper textual proxy space and regularly calibrates search outcomes with sparse
video-level evaluations. We conduct comprehensive experiments on mainstream commercial T2V models including Veo 3.1, Sora 2, Seedance and Kling v1. Results show BSB surpasses all existing jailbreak baselines, delivering an average 18.6% relative gain in attack success rate over the strongest competitor across evaluated models. Our findings identify temporal consistency as an understudied yet vital attack surface for T2V models and verify that structured search facilitates effective vulnerability discovery under constrained query budgets.
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All authors Xingkai Peng, Jun Jiang, Jiayang Liu, Kejiang Chen, Weiming Zhang
Cryptography and Security
SpexPay: A Privacy-Preserving Pay-As-You-Go System for Dynamic Spectrum Sharing
Mohaimin Al Barat, Hexuan Yu, Shaoyu Li et al. (+5 more)
Dynamic Spectrum Sharing (DSS) is a cornerstone of next-generation wireless systems, yet existing solutions such as Spectrum Access Systems (SAS) rely on centralized administrators that expose sensitive operational metadata and lack cryptographic transaction accountability. Though SAS administrators, such as Google, have introduced pay-as-you-go pricing models, these approaches still face significant
privacy and accountability challenges as DSS evolves toward a more open and large-scale spectrum marketplace. We present SpexPay, a
privacy-preserving and auditable pay-as-you-go spectrum usage framework that enforces fine-grained, usage-linked payments without revealing user identities. Spexpay integrates BBS+ verifiable credentials, unlinkable session pseudonyms, and selective-disclosure proofs to enforce
privacy-preserving access authorization, while leveraging Solidity-based smart contracts to realize automated and non-repudiable escrow settlement. By recording only pseudonymous usage evidence and hash-chained metering data on-chain, the system achieves strong unlinkability while preserving verifiable accountability and auditability. A full prototype demonstrates low end-to-end latency ($\approx$150 ms) and modest on-chain cost ($\approx$603K gas or $\approx$\$0.9), showing that SpexPay is practical for real-world DSS deployments. We also evaluated the user-side cryptographic operations on a Raspberry Pi 5 to assess scalability and suitability for edge-class hardware. Our code and artifacts are publicly available at https://github.com/iambarat/SpexPay.
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All authors Mohaimin Al Barat, Hexuan Yu, Shaoyu Li, Yang Xiao, Yi Shi, Eric W. Burger, Y. Thomas Hou, Wenjing Lou
Cryptography and Security
Fast and Private Max-Sum Diversification
Ron Zadicario and Tova Milo
Result diversification is crucial for generating informative, non-redundant data summaries and query outputs. Although its various formulations have been extensively studied across an array of data-driven disciplines, existing methods fail to address the
privacy concerns that arise when the underlying data is sensitive. In this work, we initiate the study of result diversification under differential
privacy, focusing on the max-sum diversification (MSD) problem, a widely adopted model with the objective of maximizing a linear combination of a submodular function, quantifying relevance, and the sum of pairwise distances between selected items, quantifying diversity. We propose differentially private
algorithms for MSD under both cardinality and matroid constraints, achieving nearly optimal utility guarantees. At the same time, we design more efficient
algorithms that maintain strong guarantees. Notably, the proposed
algorithms are faster than existing non-private methods, making them appealing even in non-private settings. Experimental evaluations on real-world
datasets demonstrate that the proposed approach achieves utility comparable to that of non-private baselines even under strong
privacy guarantees, and significantly improves execution times for cardinality constraints.
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Cryptography and Security
How Jailbreak Attacks Inform Safety Alignment: A Defender-Centric, Shapley-Based Evaluation of Jailbreak Contributions
Yukai Zhou, Feiyang Lu, Xiaokai Mao et al. (+2 more)
Jailbreak attacks on large
language models are usually evaluated by attacker-centric metrics such as attack success rate (ASR), yet an attack that breaks a model is not necessarily useful for improving its safety. We propose a defender-centric view of jailbreak evaluation, where attacks are evaluated by the downstream safety improvements they enable when used as red-teaming data for safety training. Building on this view, we introduce A-MESS (Minimal Effective Attack-Subset Selection), a setting-agnostic framework for attributing and selecting jailbreak attacks from black-box subset utility observations. A-MESS estimates AttackSHAP, a Shapley-based score that attributes marginal utility to individual attacks and selects compact attack subsets under user-specified budgets via greedy or surrogate-based optimization. Across controlled utility landscapes and real LLM safety settings, we find that ASR rankings are weakly aligned with defender-centric utility, that AttackSHAP can be estimated accurately with limited utility queries, and that directly optimizing subsets yields stronger safety utility than attacker-centric or attribution-only selection. These results suggest evaluating jailbreak attacks as resources for improving safety, not only as tools for breaking models.
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All authors Yukai Zhou, Feiyang Lu, Xiaokai Mao, Jinfei Liu, Wenjie Wang
Cryptography and Security
SlotGuard: Stop Oversharing Private Local Context in LLM Agent Transcri
Haocheng Xia and Yongjoo Park
LLM
agents can leak
privacy (e.g., paths, emails) and credentials (e.g., API keys) as
agent observations (e.g., tool outputs, shell logs, and file reads) are appended to provider-bound transcripts. Existing placeholder redaction is brittle: it can miss embedded or cross-turn references, over-redact benign lookalikes, and destroy the structure useful for
reasoning. We present SlotGuard, a local transcript boundary that can hide sensitive data while retaining
agents' performance. SlotGuard rewrites structural bindings as typed, suffix-aware slots, replaces secrets with format-preserving synthetic values, links cross-turn references with a lightweight session graph, and restores raw values only inside the trusted runtime. On controlled repository-oriented
agent transcripts, SlotGuard removes all 20,814 annotated structurally sensitive characters across 9,229 paths and reduces credential leakage to 0.0% across 852 planted values. It remains close to raw-transcript task success across four upstream models, while generic redaction drops to 2.5%. Transcript rewriting takes a median of 14.424~$\mu$s per
agent turn. The code is publicly accessible at https://github.com/illinoisdata/SlotGuard.
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Cryptography and Security
DSA Nonce Vulnerabilities: An Interactive Analysis
Rundong Wei, Xiaomei Tian and Xiaoqi Li
Digital signatures are fundamental to identity authentication and data integrity in cybersecurity, and the NIST-standardized Digital Signature
Algorithm (DSA) frequently appears in the cryptography track of CTF competitions. However, DSA relies on number theory, modular arithmetic, and large-integer computation, making both the
algorithm and its associated attacks difficult for beginners to follow. Conventional tools often expose only inputs and outputs, leaving the intermediate computations of signing, verification, and key-recovery attacks opaque. This paper presents a DSA signature analysis and visualisation platform tailored to CTF competitions. The platform provides three main capabilities: basic signature generation and verification, reproduction of common CTF attack methods, and dynamic visualisation of attack workflows. It covers three representative nonce vulnerabilities: nonce reuse, linear nonce leakage, and HNP-based
lattice attacks. Stepwise displays and highlighted intermediate values make the underlying computations directly inspectable. Experiments show that the platform correctly reproduces the standard DSA workflow and all three attack scenarios.
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Cryptography and Security
A Multi-Model Hybrid Defense Approach Against White-box Adversarial Attacks in Computer Network Traffic
Khushnaseeb Roshan
It is crucial to safeguard computer networks from evolving network security threats and unknown cyberattacks. An essential tool for protecting computer networks against unknown cyber threats is Network Intrusion Detection System (NIDS). However, NIDS faces a major security concern due to its susceptibility to
adversarial attacks.
Adversarial attacks aim to deceive NIDS by crafting and injecting
adversarial examples into the system. These
adversarial inputs can deceive the NIDS into misclassifying benign network traffic as malicious. We developed a resilient hybrid defense mechanism aimed to mitigate the impact of two potent
adversarial attacks: Fast Gradient Sign Method (FGSM) and Carlini & Wagner (C&W) attack. Our hybrid defense approach leverages the combined strength of two heuristic defense methods:
Adversarial Training (AT) and Gaussian Data Augmentation (GDA). GDA provides multi-directional defense, while AT enhances NIDS robustness against specific
adversarial vectors. Under pre-attack scenarios, NIDS demonstrated good accuracy and f1-score. However, in the post-attack scenario, its accuracy significantly dropped under FGSM and C&W attacks (0.2649 and 0.4961, respectively). Our proposed hybrid defense method effectively mitigated these
adversarial threats, with post-defense accuracy of 96.57% and 89.20% for FGSM and C&W attacks. We evaluated the defense strategy across a range of epsilon and confidence noise factor values (ranging from 0.0001 to 0.0009). This research provides a good direction for future researchers in the emerging area of
adversarial machine learning from a security perspective.
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Cryptography and Security · Cross-listed from cs.SD
Multi-Level Privacy-Preserving Dementia Detection from Speech via Targeted Adversarial Obfuscation and Representation Learning
Henriette Flore Kenne, Raphael Anaadumba and Mohammad Arif Ul Alam
Speech recordings used for dementia detection inherently expose speaker identity, raising critical
privacy concerns. Existing methods typically address only singular threats and fail to resolve the
privacy–utility trade-off. We propose a multi-level framework designed to neutralize two distinct eavesdropping vectors. At the signal level, a Cumulative Signal Attack (CSA) concentrates perturbations in keyword-aligned regions to maximize transcription error (Word Error Rate WER = 1.00) while preserving vital prosodic biomarkers. At the feature level, a Gradient Reversal Layer (GRL) with Mutual Information (MI)-guided noise injection suppresses speaker-discriminative dimensions while retaining dementia-relevant diagnostic structure. Evaluated on the DementiaBank Pitt Corpus, our framework achieves near-chance speaker identification (Equal Error Rate EER = 0.59, F1 = 0.003) while maintaining strong dementia classification performance (F1 = 0.78, AUC = 0.86).
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Cryptography and Security
SATLOCK: Handover-Coupled Scheduling for Weather-Resilient Quantum Key Distribution over LEO Constellations
Mohammad Arif Hossain and Md Jafrin Hossain
Routing
quantum keys over low-earth-orbit (LEO) satellite constellations is harder than classical routing: satellite handovers couple consecutive scheduling decisions,
stochastic cloud cover can silently zero a ground link, and finite-key effects eliminate short, low-elevation passes entirely. We present SATLOCK, a handover-aware
Quantum Key Distribution (QKD) routing framework that combines (i) a composite channel model incorporating atmospheric loss, pointing jitter, Markov cloud cover, decoy-state estimation, and finite-key correction; (ii) an integer linear program (ILP) giving a provable handover-aware throughput upper bound; and (iii) a decentralized deep Q-network (DQN) baseline for weather-adaptive online routing. We evaluate two contention regimes on a Walker constellation serving intercontinental demands. In low contention (16 satellites, 6 demands), the ILP delivers 1,311 Mbit while the strongest heuristics reach 95–96% of ILP. In high contention (8 satellites, 12 demands), where handovers become binding, heuristics drop to 89.5% of ILP. The DQN
agent reaches 91.8% and 84.6% of ILP in the two regimes; it learns effective per-demand weather policies but is limited in aggregate by the lack of cross-demand coordination.
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Cryptography and Security
A Systematic Evaluation of Traditional Privacy Policy Analysis Tools Against LLMs
Madhav Aryal, Sudipa Saha, Sunil Manandhar et al. (+2 more)
The advent of LLMs has significantly changed the research on
privacy policy and data compliance analysis by enabling tasks that previously required specialized, domain-specific tools. However, it remains unclear to what extent LLMs can truly replicate the diverse functionalities, and the wide range of methodologies and analysis offered by prior work. In this paper, we conduct the first systematic evaluation of whether off-the-shelf LLMs can replace specialized
privacy analysis tools. We study six representative tools spanning three major functionalities: contradiction detection, regulatory compliance analysis, and
privacy policy summarization and aggregation, and across three intermediate tasks: structured data extraction using tuples, Semantic Role Labeling (SRL) and manual
privacy policy labeling. We compare the performance of two state-of-the-art LLMs (GPT-5.2 and Gemini-2.5 in various configurations) against the tools by directly prompting the models to perform corresponding functionalities and tasks on a custom
dataset of 10
privacy policies, allowing us to assess whether off-the-shelf models can produce tool-specific functionalities without further engineering or domain-specific training, major limitations in prior work. Our results show that LLMs consistently match or exceed the capabilities of existing tools across the functionalities. In manual labeling of first-party collection entities, LLMs achieved an average precision of 81.8% and recall of 70.9%, while for labeling of third-party sharing entities, they achieved an average precision of 91.4% and recall of 70.8% compared to the OPP-115
dataset. Overall, our findings indicate that LLMs can effectively perform a broad range of functionalities and tasks in
privacy policy and regulation analysis that previously required specialized tools.
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All authors Madhav Aryal, Sudipa Saha, Sunil Manandhar, Anshuman Chhabra, Kaushal Kafle
Cryptography and Security
Federated Learning and LLM-Driven Threat Intelligence for Zero Trust IoT Architecture
Amal Alshehri and Cihan Tunc
While the Internet of Things (IoT) has become essential, they introduced serious security and
privacy challenges, especially for mission-critical environments. Legacy devices are vulnerable to viruses, data breaches, and unauthorized access, and updating these devices would be infeasibly costly. As a solution, this paper presents a
Federated Learning and LLM-Driven Threat Intelligence for Zero Trust IoT Architecture, with FL for anomaly detection integrating
privacy-preserving distributed learning, continuous identity verification, and LLM-driven autonomous threat response into a unified pipeline. Unlike existing solutions, our framework enforces Zero Trust at every communication layer via mutual TLS (mTLS) over MQTT, ensuring no device or message is implicitly trusted. Our experiments with Raspberry Pis and various sensors achieve an F1 score of 0.9091 and an ROC-AUC of 1.0, highlighting the effectiveness of the proposed framework in enabling
privacy-preserving anomaly detection for resource-constrained IoT devices.
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Cryptography and Security
Federated Lightweight Intrusion Detection in Drone Swarms with Knowledge Distillation
Fawaz J. Alruwaili and Cihan Tunc
Drone swarms are increasingly deployed in critical applications such as surveillance, disaster response, and infrastructure monitoring. However, their reliance on open communication channels and their limited computational resources make them vulnerable to a wide range of cyber-threats. There is a growing interest in intrusion detection systems (IDS) specifically designed for drone environments and operations. However, the conventional solutions including Machine Learning (ML)-based approaches require collecting all data from heterogeneous drones in the swarm and processing on a central server may not be always feasible.
Federated Learning (FL) has emerged as a promising distributed solution with an additional
privacy-preserving feature. Even though potential studies exist, conventional FL-based IDS frameworks still face communication and computational overhead challenges, while achieving a balance between efficiency and effective detection under practical resource constraints remains a challenge. Therefore, we propose a lightweight FL-based IDS tailored for drone swarm networks using deep neural networks (DNN) enhanced with knowledge
distillation (KD) to reduce model complexity and communication costs without sacrificing detection performance. We evaluate our framework using Raspberry Pi 4 devices and a real-world drone network
dataset. Our approach demonstrates a detection accuracy of approximately 98.6% while reducing overall communication cost by around 70% and computational overhead by 29%. These results show that FL combined with KD is a practical and suitable solution for secure and efficient deployment in resource-constrained drone networks.
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