Cryptography and Security
XAI and Statistical Analysis for Reliable Intrusion Detection in the UAVIDS-2025 Dataset: From Tree to Hybrid and Tabular DNN Ensembles
Iakovos-Christos Zarkadis and Christos Douligeris
During thDuring the last few years, the term Mechanistic Interpretability, a specific area, under the umbrella of explainable artificial intelligence (XAI), has been introduced, to explain the decisions made by complex machine learning (ML) models in critical systems like
UAV intrusion detection systems (UAVIDS). In this paper, we apply best-practices for data pre-processing and examine a wide range of tree-ensembles, deep neural networks, hybrid stacking models and the latest ensemble neural networks to detect intrusions in
UAV, with stratified 10-fold cross validation. With our top-performing model, XGBoost, we proceed to Shapley Additive explanations (SHAP), to analyze the global and local feature importances and understand which features, each attack targets, to mimic normal traffic and where the misclassifications occur. Furthermore a distribution analysis follows, by visually comparing violin plots and the curves of kernel density estimations. With the Westfall-Young permutation test for multiple comparisons, the Bandwidth optimization of the KDEs and the selection of Jensen-Shannon Distance for the test, we discover the true causes of false predictions, observed in Wormhole and Blackhole attacks in UAVIDS-2025. The findings provide robust, reliable and explainable models for
UAV intrusion detection, along with statistical insights, which capture and clarify the masked nature of the attacks, regarding the challenge of Density Support Intersection, between these attacks, in this
dataset.
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Cryptography and Security · Cross-listed from quant-ph
Backdoor Threats in Variational Quantum Circuits: Taxonomy, Attacks, and Defenses
Lei Jiang and Fan Chen
Variational
quantum algorithms (VQAs) are a central paradigm for noisy intermediate-scale (NISQ)
quantum computing, yet their reliance on predesigned and pretrained variational
quantum circuits (VQCs) introduces critical security vulnerabilities, particularly
backdoor attacks. These attacks embed hidden malicious behaviors that remain dormant under normal conditions but are activated by specific triggers, leading to
adversarial outcomes such as incorrect predictions or manipulated objective values. This paper presents a survey of
backdoor attacks in VQCs, covering data-poisoning, compiler-level, and
quantum-native mechanisms. We formalize key terminology and threat models, and review existing attack strategies along with their empirical characteristics. We also analyze current detection and defense approaches, highlighting their limitations, especially against
quantum-specific threats. By synthesizing recent advances, this survey outlines the evolving security landscape of VQCs and identifies key challenges and future directions for developing robust,
quantum-aware defenses in hybrid
quantum-classical systems.
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Cryptography and Security
VectorSmuggle: Steganographic Exfiltration in Embedding Stores and a Cryptographic Provenance Defense
Jascha Wanger
Modern
retrieval-augmented generation (RAG) systems convert sensitive content into high-dimensional
embeddings and store them in vector databases that treat the resulting numerical artifacts as opaque. Major vector-store products do not provide native controls for
embedding integrity, ingestion-time distributional anomaly detection, or cryptographic provenance attestation. We show this opens a class of steganographic exfiltration attacks: an attacker with write access to the ingestion pipeline can hide payload data inside
embeddings using simple post-
embedding perturbations (noise injection, rotation, scaling, offset, fragmentation, and combinations thereof) while preserving the surface-level
retrieval behavior the RAG system exposes to legitimate users. We evaluate these techniques across a synthetic-PII corpus on text-
embedding-3-large, four locally hosted open
embedding models, a cross-corpus replication on BEIR NFCorpus and a Quora subset (over 26,000 chunks combined), seven vector-store configurations, an adaptive-attacker variant of the detector evaluation, and a paraphrased-query
retrieval benchmark. Distribution-shifting perturbations are often caught by simple anomaly detectors; small-angle orthogonal rotation defeats distribution-based detection across every (model, corpus) pair tested. A disjoint-Givens rotation encoder gives a closed-form per-vector capacity ceiling of floor(d/2) * b bits, but real
embedding manifolds impose a capacity-detectability trade-off, and the
retrieval-preserving operating point sits well below it. We propose VectorPin, a cryptographic provenance protocol that pins each
embedding to its source content and producing model via an Ed25519 signature over a canonical byte representation. Any post-
embedding modification breaks signature verification.
Embedding-level integrity is a deployable, standardizable control that closes this attack class.
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Cryptography and Security
DisAgg: Distributed Aggregators for Efficient Secure Aggregation in Federated Learning
Haaris Mehmood, Giorgos Tatsis, Dimitrios Alexopoulos et al. (+4 more)
Federated learning enables collaborative model training across distributed clients, yet vanilla FL exposes client updates to the central server. Secure-aggregation schemes protect
privacy against an honest-but-curious server, but existing approaches often suffer from many communication rounds, heavy public-key operations, or difficulty handling client dropouts. Recent methods like One-Shot Private Aggregation (OPA) cut rounds to a single server interaction per FL iteration, yet they impose substantial cryptographic and computational overhead on both server and clients. We propose a new protocol called DisAgg that leverages a small committee of clients called Aggregators to perform the aggregation itself: each client secret-shares its update vector to Aggregators, which locally compute partial sums and return only aggregated shares for server-side reconstruction. This design eliminates local masking and expensive homomorphic encryption, reducing endpoint computation while preserving
privacy against a curious server and a limited fraction of colluding clients. By leveraging optimal trade-offs between communication and computation costs, DisAgg processes 100k-dimensional update vectors from 100k 5G clients with a 4.6x speedup compared to OPA, the previous best protocol.
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All authors Haaris Mehmood, Giorgos Tatsis, Dimitrios Alexopoulos, Karthikeyan Saravanan, Jie Xu, Anastasios Drosou, Mete Ozay
Cryptography and Security
Identifying AI Web Scrapers Using Canary Tokens
Steven Seiden, Triss Ren, Caroline Zhang et al. (+3 more)
From pre-training to query-time augmentation, web-scraped data helps to improve the quality and contextual relevancy of content generated by large
language models (LLMs). However, large-scale web scraping to feed LLMs can affect site stability and raise legal,
privacy, or ethics concerns. If website owners wish to limit LLM-related web scraping on their site, due to these or other concerns, they may turn to scraper access control mechanisms like the
Robots Exclusion Protocol. To be most effective, such mechanisms require site owners to first identify the scrapers that they wish to restrict (e.g., via User-
Agent strings). Existing mechanisms to identify LLM-related scrapers rely on voluntary disclosure by companies, one-off experiments by researchers, or crowd-sourced reports – methods that are neither reliable nor scalable. This paper proposes a novel technique for accurately and automatically inferring LLM-related scrapers. We host dynamic websites that serve unique canary
tokens to each visiting scraper, then
prompt LLMs for information about our sites. If an LLM consistently generates outputs containing
tokens unique to a scraper, it provides evidence of exposure to that scraper. Via experiments across 22 production LLM systems, we demonstrate that our approach can reliably identify which scrapers feed which LLM, including several that are not publicly known or disclosed by the companies. Our approach provides a promising avenue for unprivileged third parties to infer which scrapers serve data to which LLMs, potentially enabling better control over unwanted scraping.
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All authors Steven Seiden, Triss Ren, Caroline Zhang, Taein Kim, Enze Liu, Emily Wenger
Cryptography and Security
MQTT Across a Raspberry Pi 5 IoT Network Utilizing Quantum-resistant Signature Algorithms
Ray Feingold and Chansu Yu
The rapid expansion of the Internet of Things (IoT) has introduced millions of resource-constrained devices into critical infrastructures, consumer environments, and industrial systems. These devices rely on lightweight communication protocols such as MQTT to support low-power, intermittent, and bandwidth-limited operation. However, common TLS
algorithms used to secure MQTT communications are vulnerable to
quantum attacks made feasible by Shor's
algorithm. As a result, IoT infrastructures must evaluate and adopt post-
quantum cryptographic (PQC) methods capable of providing long-term resilience. This report investigates the implementation of PQC
algorithms within an MQTT-based IoT networks using three Raspberry Pis. Specifically, it integrates the FALCON digital signature scheme, one of NIST's selected post-
quantum signature
algorithms, to maintain message authenticity and integrity across resource-constrained MQTT clients and brokers. By measuring system performance, the research characterizes the practical trade-offs of deploying
lattice-based PQC on lightweight hardware.
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Cryptography and Security
EBCC: Enclave-Backed Confidential Containers via OCI-Compatible Runtime Integration
Di Lu, Qingwen Zhang, Yujia Liu et al. (+4 more)
Container runtimes provide a stable operational interface for deploying, monitoring, and controlling modern workloads, while trusted execution environments (TEEs) provide hardware-enforced isolation for sensitive computation. Existing confidential-container systems often rely on VM-backed deployment stacks or TEE-specific execution substrates, which can separate confidential execution from the conventional OCI runtime lifecycle. This paper presents EBCC (Enclave-Backed Confidential Containers), an OCI-compatible runtime architecture for managing composite confidential-computing workloads. EBCC treats the REE-side anchor and TEE-side confidential stages as a single containerized confidential-computing composite, preserves standard OCI lifecycle operations, and keeps TEE-specific execution behind a backend adapter. It also maintains persistent per-instance state and per-stage artifacts for request handling, response generation, logging, and evidence binding. We implement EBCC on a Keystone backend and evaluate its correctness, performance, footprint, and concurrent execution behavior. The results show that EBCC introduces additional latency over native Keystone execution, mainly due to lifecycle mediation, request validation, EID allocation, backend dispatch, and artifact persistence, while keeping the added footprint concentrated on host-side management state. Cross-TEE case studies on SGX, TDX, and OP-TEE show that the same lifecycle and stage abstraction can be mapped to enclave-style, VM-style, and embedded-style TEEs. These results indicate that EBCC can make TEE-backed execution manageable through an OCI-style lifecycle without materially enlarging the protected-side TCB.
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All authors Di Lu, Qingwen Zhang, Yujia Liu, Xuewen Dong, Yulong Shen, Zhiquan Liu, Jianfeng Ma
Cryptography and Security
Limits of Personalizing Differential Privacy Budgets
Edwige Cyffers and Juba Ziani
A key technical difficulty in differential
privacy is selecting a
privacy budget that satisfies
privacy requirements while maximizing utility. A natural and well-studied workaround is to use personalized
privacy budgets, which may differ across
agents. In this paper, we show that personalized budgets come with major limitations and that for mean estimation, the dominant factor is not full personalization, but rather choosing the right effective
privacy budget. This can be achieved through a simple thresholding operator that we describe. Compared with this thresholding baseline, the gains obtained by fully personalized mechanisms are limited. In particular, we precisely quantify the constant-factor improvement in settings with mixed private and public
datasets and in private
datasets with two levels of
privacy requirements. We also establish upper bounds and identify regimes of maximal gain for arbitrary
privacy requirements.
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Cryptography and Security · Cross-listed from cs.RO
Uncertainty-Aware 3D Position Refinement for Multi-UAV Systems
Hosam Alamleh and Damir Pulatov
Reliable real-time 3D localization is essential for multi-
UAV navigation, collision avoidance, and coordinated flight, yet onboard estimates can degrade under GNSS multipath, non-line-of-sight reception, vertical drift, and intentional interference. This paper presents a decentralized, lightweight 3D position-refinement layer that improves robustness by fusing each Unmanned Aerial Vehicle (
UAV)'s local estimate with neighbor-shared state summaries and inter-
UAV range or proximity constraints. The method performs uncertainty-aware neighborhood fusion by weighting each
UAV's prior according to its reported covariance and weighting neighbor constraints according to link quality, ranging uncertainty, and a learned trust score. To support practical deployment, the framework explicitly handles cold start and temporary localization loss by inflating or substituting weak priors, allowing trusted neighborhood constraints to bootstrap and stabilize estimates until absolute sensing recovers. To mitigate the impact of faulty or malicious participants, each
UAV applies a local range-consistency check, smoothed over time, to down-weight or exclude neighbors whose reported positions are incompatible with observed inter-
UAV distances. Simulation experiments with 10
UAVs in a 3D volume show that the proposed refinement substantially reduces mean localization error during cold start, remains competitive after local
estimators stabilize, and maintains lower error as the fraction of malicious nodes increases compared with fusion without trust. These results suggest that the approach can serve as a practical resilience layer for swarm operation in challenging environments.
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Cryptography and Security
Phantom Force: Injecting Adversarial Tactile Perceptions into Embodied Intelligence via EMI
Zirui Kong, Youqian Zhang and Sze Yiu Chau
Embodied intelligent
robots rely on tactile sensors to interact with the physical world safely. While the security of visual perception systems has been studied (e.g.,
adversarial samples), the integrity of the tactile sensory channel remains unexplored. This work explores a vulnerability in
Hall-effect fingertip sensors, showing their susceptibility to intentional Electromagnetic Interference (EMI). We demonstrate that a targeted signal injection can induce strong "phantom forces", amplifying perceived force magnitude by over 9$\times$ and deviating the inferred force direction by 65$^\circ$. Such perturbations can paralyze learning-based tactile classification models, seriously affecting
robot movement. An attacker could exploit this vulnerability to coerce a
robot hand into crushing fragile objects or dropping dangerous payloads.
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Cryptography and Security
Sleeper Channels and Provenance Gates: Persistent Prompt Injection in Always-on Autonomous AI Agents
Narek Maloyan and Dmitry Namiot
Always-on AI
agents (OpenClaw, Hermes
Agent) run as a single persistent process under the owner's identity, folding messaging,
memory, self-authored skills, scheduling, and shell into one authority boundary. This configuration opens what we call sleeper channels: an untrusted input to one surface persists as a
memory, skill, scheduled job, or filesystem patch, then fires later through a different surface with no attacker present. Two independent axes define the class: persistence substrate and firing-separation. We walk a confused-deputy cron attack end-to-end through OpenClaw at a pinned commit. The defense is tiered (D1, D2, D3), and D2 carries a soundness
theorem against seven named deployment invariants. D2 keys on a canonical action-instance digest with one-shot owner attestations, defeating paraphrase laundering, multi-input grant reuse, and replay. A companion artifact ships the gate, a static audit over the vendored source, and a runtime adapter realising five of the ten mediation hooks (H1, H2, H3, H6, H9) around the cron path (42 tests, Node~$\geq{}20$, at \href{https://github.com/maloyan/sleeper-channels}{github.com/maloyan/sleeper-channels}). Empirical evaluation is preregistered as follow-on.
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Cryptography and Security
Model-Agnostic Lifelong LLM Safety via Externalized Attack-Defense Co-Evolution
Xiaozhe Zhang, Chaozhuo Li, Hui Liu et al. (+4 more)
Large
language models remain vulnerable to
adversarial prompts that elicit harmful outputs. Existing safety paradigms typically couple red-teaming and post-training in a closed, policy-centric loop, causing attack discovery to suffer from rapid saturation and limiting the exposure of novel failure modes, while leaving defenses inefficient, rigid, and difficult to transfer across victim models. To this end, we propose EvoSafety, an LLM safety framework built around persistent, inspectable, and reusable external structures. For red teaming, EvoSafety equips the attack policy with an
adversarial skill library, enabling continued vulnerability probing through simple library expansion after saturation, while supporting the
evolution of
adversarial vectors. For defense learning, EvoSafety replaces model-specific safety fine-tuning with a lightweight auxiliary defense model augmented with
memory retrieval. This enables efficient, transferable, and model-agnostic safety improvements, while allowing robustness to be enhanced solely through
memory updates. With a single training procedure, the defense policy can operate in both Steer and Guard modes: the former activates the victim model's intrinsic defense mechanisms, while the latter directly filters harmful inputs. Extensive experiments demonstrate the superiority of EvoSafety: in Guard mode, it achieves a 99.61% defense success rate, outperforming Qwen3Guard-8B by 14.13% with only 37.5% of its parameters, while preserving
reasoning performance on benign queries. Warning: This paper contains potentially harmful text.
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All authors Xiaozhe Zhang, Chaozhuo Li, Hui Liu, Shaocheng Yan, Bingyu Yan, Qiwei Ye, Haoliang Li
Cryptography and Security
Inducing Overthink: Hierarchical Genetic Algorithm-based DoS Attack on Black-Box Large Language Reasoning Models
Shuqiang Wang, Wei Cao, Jiaqi Weng et al. (+4 more)
Large
Reasoning Models (LRMs) are increasingly integrated into systems requiring reliable multi-step inference, yet this growing dependence exposes new vulnerabilities related to computational availability. In particular, LRMs exhibit a tendency to "overthink", producing excessively long and redundant
reasoning traces, when confronted with incomplete or logically inconsistent inputs. This behavior significantly increases inference latency and energy consumption, forming a potential vector for denial-of-service (DoS) style resource exhaustion. In this work, we investigate this attack surface and propose an automated black-box framework that induces overthinking in LRMs by systematically perturbing the logical structure of input problems. Our method employs a hierarchical genetic
algorithm (HGA) operating on structured problem decompositions, and optimizes a composite fitness function designed to maximize both response length and reflective overthinking markers. Across four state-of-the-art
reasoning models, the proposed method substantially amplifies output length, achieving up to a 26.1x increase on the MATH
benchmark and consistently outperforming benign and manually crafted missing-premise baselines. We further demonstrate strong transferability, showing that
adversarial inputs evolved using a small proxy model retain high effectiveness against large commercial LRMs. These findings highlight overthinking as a shared and exploitable vulnerability in modern
reasoning systems, underscoring the need for more robust defenses.
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All authors Shuqiang Wang, Wei Cao, Jiaqi Weng, Jialing Tao, Licheng Pan, Hui Xue, Zhixuan Chu
Cryptography and Security
Context-Aware Web Attack Detection in Open-Source SIEM Systems via MITRE ATT&CK-Enriched Behavioral Profiling
Badr Alboushy, Assef Jafar, Mohamad Aljnidi et al. (+2 more)
Security Information and Event Management (SIEM) systems aggregate log data from heterogeneous sources to detect coordinated attacks. Traditional rule-based correlation engines struggle to classify multi-step web application attacks because they examine each event without reference to the behavioural history of the originating host. We present Smart-SIEM, an AI module for the open-source Wazuh SIEM platform with two contributions: (1) a per-source-IP behavioural context vector encoding HTTP response-status distributions, peak rule activation counts, and MITRE ATT&CK technique frequencies from the N most recent prior events; (2) a two-stage hybrid cascade combining LightGBM for binary attack detection and XGBoost for six-class attack categorisation. Evaluated on 46,454 purpose-built Wazuh security events, context features improve all tested gradient boosting
algorithms from ~0.705 macro F1 to 0.947-0.967 (Stage 1) and 0.876-0.914 (Stage 2), an average gain of +0.254 and +0.324 respectively. The hybrid cascade achieves F1 of 0.967 (binary) and 0.914 (six-class). Wazuh's native rule engine detects 0% of Brute Force and Broken Authentication events; the AI module detects 100% and 98.3% respectively. A self-adaptive retraining mechanism recovers from concept drift: F1 drops from 0.905 to 0.465 when unseen attack types emerge, recovering to 0.814 after retraining on the combined corpus.
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All authors Badr Alboushy, Assef Jafar, Mohamad Aljnidi, Mohamad Bashar Disoki, Aref Shaheed
Cryptography and Security · Cross-listed from cs.LG
LightSplit: Practical Privacy-Preserving Split Learning via Orthogonal Projections (Full Version)
Mert Cihangiroglu, Alessandro Pegoraro, Phillip Rieger et al. (+2 more)
Split learning (SL) enables collaborative training by partitioning a neural network across clients and a central server. However, the cut-layer interface introduces a key challenge: high-dimensional activations incur substantial communication overhead while exposing representations vulnerable to reconstruction attacks. Existing approaches typically address efficiency or
privacy in isolation. We propose LightSplit, which limits information exposure and reduces communication overhead via a lightweight fixed orthogonal random projection at the cut layer. Based on Shannon's information theory, this projection acts as an information bottleneck that restricts instance-specific information and suppresses exploitable per-sample signals. With low-dimensional projections sent instead of raw activations, the server operates on lifted representations without requiring changes to existing SL architectures. Adding no trainable client components, LightSplit remains lightweight and suitable for edge devices while preserving end-to-end differentiability via exact gradient propagation. As the projection is non-invertible, part of the original representation is irreversibly discarded at the client, so LightSplit reduces the information available for reconstruction. We evaluate LightSplit on seven
benchmarks spanning image classification, tabular data, and
language-model fine-tuning, under IID and non-IID client data. At up to 32x compression it retains at least 94% of baseline accuracy on CIFAR-10, FashionMNIST, GTSRB, and UCI HAR, 86% on CIFAR-100, and 91% on average under non-IID client data; at 8x it retains 92% of ImageNet-1k top-1 and raises GPT-2 perplexity by at most 1.15x. Against state-of-the-art reconstruction attacks LightSplit resists inversion; the strongest, co-trained attack loses up to 87.3% of its reconstruction SSIM, and subject re-identification on UCI HAR drops by more than half.
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All authors Mert Cihangiroglu, Alessandro Pegoraro, Phillip Rieger, Antonino Nocera, Ahmad-Reza Sadeghi
Cryptography and Security
Automatic Detection of Reference Counting Bugs in Linux Kernel Drivers
Joe Hattori, Naoki Kobayashi and Ken Sakayori
Reference counting bugs in Linux kernel drivers can lead to severe resource mismanagement and security vulnerabilities. We introduce DrvHorn, a novel automated tool to detect these bugs by reducing reference counting verification to an assertion checking problem leveraging the Linux driver interface. Through efficient modeling of the Linux kernel and aggressive program slicing, DrvHorn discovered 545 bugs, of which 424 were previously unknown, across all platform drivers in v6.6 Linux kernel, with a lower false positive rate of 29.9% compared to prior studies. To address the root causes of these newly discovered bugs, we submitted patches to the Linux kernel, and 45 of them were merged.
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Cryptography and Security
Backdoor Channels Hidden in Latent Space: Extending Cryptographic Undetectability to Modern Neural Networks
Marte Eggen, Eirik Reiestad, Kristian Gjøsteen et al. (+1 more)
Recent cryptographic results establish that neural networks can be backdoored such that no efficient
algorithm can distinguish them from a clean model. These guarantees, however, have been confined to stylised architectures of limited practical relevance, leaving open whether comparable undetectability extends to modern, end-to-end trained networks. We construct such an attack mechanism for state-of-the-art architectures, closely aligned to the cryptographic notion of undetectability, by identifying
backdoor channels as learned latent directions, and show that the question of undetectability reduces to a hypothesis test between two unknown distributions over model parameters, which we
conjecture to be intractable in practice. The consequence of this reframing is significant: if exploitable channels within a network's latent space are statistically indistinguishable from naturally learned directions, an attacker need not introduce foreign structure but can instead exploit the geometry the network already possesses. Demonstrating the approach on ResNet and
Vision Transformer architectures trained on standard image classification
datasets, the attack achieves both consistently high success rates with negligible clean accuracy degradation, and resists a comprehensive suite of post-training defences, none of which neutralise the
backdoor without rendering the model unusable. Our results establish that cryptographic
backdoors need not be artefacts requiring exotic architectures or artificial constructions, but identifiable as latent properties inherent to the geometry of learned representations.
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All authors Marte Eggen, Eirik Reiestad, Kristian Gjøsteen, Inga Strümke
Cryptography and Security · Cross-listed from cs.AR
PoisonCap: Efficient Hierarchical Temporal Safety for CHERI
Yuecheng Wang, Jonathan Woodruff, Alfredo Mazzinghi et al. (+5 more)
In this paper, we present PoisonCap: scalable temporal safety with strict use-after-free protection and initialisation safety for CHERI systems. Efficient
memory safety is an increasing priority for programming
languages, operating systems, and hardware designs, and CHERI is a leading hardware/software system that provides native spatial safety and a foundation for temporal
memory safety. Cornucopia Reloaded, the current state-of-the-art CHERI temporal safety solution, provides use-after-reallocation safety instead of stronger use-after-free safety, and is not able to enforce initialisation safety. We show that a new 'poison' capability format can be used to enforce strict use-after-free and initialisation safety, and also to communicate
memory state to the microarchitecture for efficient cache management of quarantined
memory. We enable elegant delegation of
memory poisoning privilege using capability bounds to allow nested allocators to enforce safety on their consumers without disturbing upstream allocators. PoisonCap can replace the Cornucopia shadow bitmap, and also automatically zeros
memory on reallocation, or optionally traps on read-before-write to enforce initialisation safety. As a result, it incurs no fundamental overhead relative to a Cornucopia baseline that zeros before reallocation, strengthening CHERI temporal safety without performance overhead.
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All authors Yuecheng Wang, Jonathan Woodruff, Alfredo Mazzinghi, Peter Rugg, Alexandre Joannou, Samuel W. Stark, Robert N. M. Watson, Simon W. Moore
Cryptography and Security
LoREnc: Low-Rank Encryption for Securing Foundation Models and LoRA Adapters
Beomjin Ahn, Jungmin Kwon, Chanyong Jung et al. (+1 more)
Foundation models and low-rank adapters enable efficient on-device generative AI but raise risks such as intellectual property leakage and model recovery attacks. Existing defenses are often impractical because they require retraining or access to the original
dataset. We propose LoREnc, a training-free framework that secures both FMs and adapters via spectral truncation and compensation. LoREnc suppresses dominant low-rank components of FM weights, compensates for the missing information in authorized adapters, and further applies orthogonal reparameterization to obscure structural fingerprints of the protected adapter. Unauthorized users produce structurally collapsed outputs, while authorized users recover exact performance. Experiments demonstrate that LoREnc provides strong protection against model recovery with under 1% computational overhead.
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All authors Beomjin Ahn, Jungmin Kwon, Chanyong Jung, Jaewook Chung
Cryptography and Security
Empowering IoT Security: On-Device Intrusion Detection in Resource Constrained Devices
Vasilis Ieropoulos, Eirini Anthi, Theodoros Spyridopoulos et al. (+3 more)
IoT devices particularly microcontrollers are challenged by their inherent limitations in processing capabilities,
memory capacity, and energy conservation. Securing communication within IoT networks is further complicated by the heterogeneity of devices and the myriad of potential security threats. Our study introduces a lightweight model that utilises machine learning
algorithms to achieve a notable detection accuracy of 99% using a decision tree method and 96% using a neural network in identifying cyber threats, including Denial of Service and Man-in-the-Middle attacks which make up the majority of the attacks these devices face. While the decision tree method offers higher accuracy, it requires more computational resources, whereas the neural network approach, despite a slightly lower accuracy, is more
memory-efficient. Both methods enhance the real-time monitoring and defence of IoT networks, safeguarding the transmission of data. Additionally, our approach is tailored to conserve
memory and optimise computational demands, rendering it suitable for deployment on microcontrollers with limited resources.
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All authors Vasilis Ieropoulos, Eirini Anthi, Theodoros Spyridopoulos, Pete Burnap, Aftab Khan, Pietro Carnelli
Cryptography and Security · Cross-listed from cs.SE
A Comprehensive Evaluation of Code Language Models for Security Patch Detection
Nils Loose, Joseph Bienhüls, Kristoffer Hempel et al. (+2 more)
Automated detection of vulnerability-fixing commits (\vfcs) is critical for timely security patch deployment, as advisory databases lag patch releases by a median of 25 days and many fixes never receive advisories. Code
language models are increasingly adopted for identifying VFCs, yet whether they can recognize a security fix from the code change itself remains unclear, as reported performance is shaped by commit messages, project-level data leakage, and uncertain data quality. We present a rigorous re-evaluation that jointly controls these factors through a unified framework consolidating 20 fragmented
datasets spanning more than 180000 commits. Training 270 models from 125M to 80B parameters, we isolate the code signal under group-stratified code-only evaluation and assess the impact of model capacity and additional code context, ranging from intra-procedural enrichment to inter-procedural repository context. Model capacity yields clear but insufficient gains, and the evaluated context signals provide no reliable improvement under strict false positive budgets. At a false positive rate of 0.5%, every evaluated fine-tuned code-only model misses at least 80% of vulnerability fixes. A manual expert audit further shows that label error concentrates in commits lacking CVE association and primarily distorts evaluation. We derive concrete recommendations for evaluating on aggregated VFC
datasets and release our unified framework and evaluation suite.
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All authors Nils Loose, Joseph Bienhüls, Kristoffer Hempel, Felix Mächtle, Thomas Eisenbarth
Cryptography and Security
Extending Blockchain Untraceability with Plausible Deniability
Eunchan Park, Kyonghwa Song, Won Hoi Kim et al. (+2 more)
Traditional blockchain untraceability schemes, such as mixers and
privacy coins, obscure the sender-receiver relationship by placing transfers within an anonymity set. This paper studies a stronger goal: whether the transfer event itself can be made unobservable by blending into common decentralized-finance (DeFi) activity. We introduce Deniable Covert Asset Transfer (DCAT), a class of transfers that stage common loss-producing events, such as sandwich and arbitrage operations, so that a sender appears to suffer an ordinary loss while the receiver appears to profit from it. We design and validate two DCAT instantiations: a sandwich-based transfer on Ethereum and an arbitrage-based transfer on Arbitrum. Our experiments show that, under the evaluated settings, DCAT transfers are empirically unobservable on both chains. They are syntactically identical to corresponding maximal extractable value (MEV) activities, classified as ordinary extractions by standard MEV detection tools, and leave the sender and receiver unlinked under representative forensic tools. Since syntactic inspection cannot distinguish DCAT from ordinary MEV activity, we examine whether economic semantics provide useful forensic signals. Through a large-scale study of MEV losses on Ethereum and Arbitrum, we show that key semantic features follow power laws. Extreme losses and repeatedly exploited addresses occur in the wild, and thus are not by themselves definitive evidence of collusion. This gives staged transfers plausible deniability and makes fixed-threshold detection prone to false positives. We therefore develop a multivariate statistical method for forensic triage that ranks incidents by the joint rarity of their economic footprint. Applied to real-world DeFi activity, our method narrows a large search space to suspicious cases for manual investigation; we present three such cases to illustrate this prioritization.
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All authors Eunchan Park, Kyonghwa Song, Won Hoi Kim, Wonho Song, Min Suk Kang
Cryptography and Security
DiffusionHijack: Supply-Chain PRNG Backdoor Attack on Diffusion Models and Quantum Random Number Defense
Ziyang You, Liling Zheng, Xiaoke Yang et al. (+1 more)
Diffusion models depend on pseudo-random number generators (PRNGs) for latent noise sampling. We present DiffusionHijack, a supply-chain
backdoor attack that hijacks the PRNG to deterministically control generated images. A malicious PRNG, injected via compromised packages, forces pixel-perfect reproduction of attacker-chosen content (SSIM = 1.00, N = 100 trials) on Stable
Diffusion v1.4, v1.5, and SDXL – without modifying model weights. The attack is inherently undetectable by existing model
auditing and content moderation mechanisms, as it operates entirely outside the neural network computation graph. The attack remains effective under
stochastic sampling (eta > 0), bypasses CLIP-based safety checkers (98-100% success), and operates independently of the user's
prompt. As a countermeasure, we replace the PRNG with a
quantum random number generator (QRNG), which provides information-theoretic unpredictability. Across N = 100
prompt-model combinations, QRNG defense completely neutralizes the attack, reducing output similarity to random baseline levels (SSIM < 0.20 for SD 1.x models, < 0.45 for SDXL). This work exposes a previously overlooked supply-chain vulnerability and offers a hardware-level fundamental mitigation for generative AI systems.
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All authors Ziyang You, Liling Zheng, Xiaoke Yang, Xuxing Lu
Cryptography and Security · Cross-listed from quant-ph
QCIVET: A Quantum–Classical Pipeline Integrity Framework with Contract-Based Subtype Verification and Hash-Chained Audit Traces
Esra Yeniaras and Muhammad Amin Karimov
Hybrid
quantum–classical pipelines increasingly support applications such as drug discovery, fraud detection, and cloud
quantum processing unit (QPU)
auditing, yet existing integrity-verification methods remain largely classical and fail to capture
quantum-stage behaviour. We propose QCIVET, a contract-based integrity-verification framework that models a hybrid pipeline as a sequence of stages with explicit specifications and audits it at both syntactic and semantic levels. Syntactic integrity is enforced through a hash-chained audit trail with optional external anchoring, while semantic integrity at
quantum stages is verified using a calibrated observable-deviation test grounded in the behavioural-subtyping discipline of Liskov and Wing. We prove soundness under the diamond-norm distance between
quantum channels, conditional completeness for informationally complete observable families, and compositionality under inheritance chains. We further identify a class of Z-only-sneaky overrides that evade weak single-Pauli contracts but are exposed by multi-Pauli contracts. The framework is evaluated under calibration-derived noise models from IBM
Quantum Eagle r3 and Heron r2 processors, and the subtype-separation protocol is validated end-to-end on a real ibm_fez (Heron r2) processor. QCIVET is instantiated on three representative applications: variational
quantum eigensolver (VQE) for drug discovery,
quantum-assisted fraud detection, and customer-side
auditing of cloud QPU services. The reference implementation, including a real-time verification engine with sub-millisecond per-stage commit latency, is released as open source.
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Cryptography and Security
Security Incentivization: An Empirical Study of how Micropayments Impact Code Security
Stefan Rass, Martin Pinzger, Rainer W. Alexandrowicz et al. (+5 more)
Security often receives insufficient developer
attention because it does not directly generate visible value, leading to underinvestment in practice. We evaluate a countermeasure by team-level incentives tied to measurable security improvements over time. Our semi-automated mechanism aggregates static analysis findings from Bearer, Detekt, and mobsfscan, computes security issue density, and rewards teams based on the relative improvement ratio across sprints, enabling repeatable, scriptable reporting at scale. In a controlled course experiment with 84 students across 14 teams, we compared a security-incentivized condition, in which bonus points were linked to security scanner results, against a control condition with an otherwise identical grading scheme. The treatment group achieved significantly lower security issue density overall (beta regression: $\beta = -0.396, p = 0.0342$), indicating improved measurable security under incentivization. After controlling for platform, we observed a marked front-end/back-end disparity, with back-ends showing fewer issues and higher improvement ratios under incentives, highlighting heterogeneous effects across stack layers. Notably, these gains were not the byproduct of inflated code volume, as lines of code increased similarly across groups over time. The measurement pipeline and toolchain proved feasible for scripting and automation, supporting scalable adoption in practice. Our results suggest that aligning rewards with automated security metrics can measurably improve code security and merit follow-up in professional contexts and longer development lifecycles.
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All authors Stefan Rass, Martin Pinzger, Rainer W. Alexandrowicz, Georg Sengstbratl, Johann Glock, Alexander Lercher, Fabian Oraze, Christoph Wedenig
Cryptography and Security
Watermarking Should Be Treated as a Monitoring Primitive
Toluwani Aremu, Jie Zhang and Nils Lukas
Watermarking is widely proposed for provenance, attribution, and safety monitoring in generative models. We argue that it should be evaluated and governed as a monitoring primitive through two complementary observer models. Internal observers use detector or decoder access and entity mappings for attribution; external observers learn entity-specific signals from labeled outputs without keys or detectors. With persistent entity bindings and reliable inference, either pathway can support monitoring. We show that even zero-bit watermarking supports internal attribution under per-entity multi-key deployments without explicitly encoding identity, and demonstrate external identification in selected text and image configurations. External exposure depends on persistent, learnable watermark structure and is not universal, while internal attribution also remains conditional on reliability and access. These findings motivate governance of attribution access and deployment choices alongside evaluation of design-dependent entity linkability, de-anonymization or re-identification, beyond per-sample robustness.
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Cryptography and Security
No Attack Required: Semantic Fuzzing for Specification Violations in Agent Skills
Ying Li, Hongbo Wen, Yanju Chen et al. (+3 more)
LLM-powered
agents can silently delete documents, leak credentials, or transfer funds on a routine user request, not because the
agent was attacked, but because the skill it invoked broke its own declared safety rules. We call these specification violations: benign inputs cause a skill to breach the natural-
language guardrails in its own specification, typically because the guardrail's semantics are undefined for autonomous execution, or because the implementation silently ignores the documented constraint. These violations are invisible to static analyzers, traditional fuzzers, and
prompt-injection defenses alike, yet they undermine the very contract a user trusts when installing a skill. We present Sefz, a goal-directed semantic fuzzing framework that automatically discovers specification violations in
agent skills. Sefz translates each guardrail into a reachability goal over an annotated execution trace, reducing violation checking to a deterministic graph query. An LLM-based mutator generates benign inputs whose traces progressively approach the violation patterns, guided by a multi-armed bandit that uses goal-proximity as its reward signal. On 402 real-world skills from the largest public
agent-skill marketplace, Sefz finds specification violations in 120 (29.9%), including 26 previously unknown exploitable guardrail violations in deployed skills. Six recurring specification pitfalls explain the bulk of the failures, suggesting concrete principles for safer skill design.
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All authors Ying Li, Hongbo Wen, Yanju Chen, Hanzhi Liu, Yuan Tian, Yu Feng
Cryptography and Security
Insecure Despite Proven Updated: Extracting the Root VCEK Seed on EPYC Milan via a Software-Only Attack
Muyan Shen and Yu Qin
In the official whitepaper of Secure Encrypted Virtualization with Secure Nested Paging (SEV-SNP), AMD explicitly emphasizes the capability to prevent Trusted Computing Base (TCB) rollback attacks. Cryptographically, this is realized by signing attestation reports with the Versioned Chip Endorsement Key (VCEK), which is derived by incorporating the TCB version into the hardware root seed. In this architecture, safeguarding the hardware root seed is the ultimate line of defense. However, our research reveals that this protection is insufficient on EPYC Milan by presenting a software-only exploit. Specifically, we firstly introduce MilanLaunchy attack, an exploit that achieves code execution on the AMD secure processor. Building on this foundation, we develop the BadFuse attack, which extracts the hardware root seed by exploiting a lack of write restrictions in the fuse controller. This end-to-end attack chain enables an adversary to forge valid attestation reports for any firmware version, thereby effectively undermining the security model of SEV-SNP.
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Cryptography and Security
CLOUDBURST: Cloud-Layer Observations Using Beacons for Unified Real-time Surveillance and Threat Attribution
Abraham Itzhak Weinberg
Modern cloud-native environments present a fundamentally different exfiltration threat surface than traditional file-based scenarios. Attackers targeting AWS, GCP, Azure, and OCI steal S3 presigned URLs, container images, Kubernetes secrets, Terraform state modules, and IAM role
tokens – artefacts that existing honeytoken and beacon frameworks do not address. We present CLOUDBURST, the first formal taxonomy and measurement framework for cloud-native passive beacons, comprising six vector classes across four major cloud providers. We introduce the Cloud Attribution Score (CAS), a four-component metric that explicitly models ephemeral infrastructure penalty ($E_p$), IAM coverage depth ($I_c$), and multi-cloud correlation bonus ($M_b$) – dimensions absent from all prior attribution quality metrics. Experiments across $21$ deployed beacons, $205$ simulated callbacks, and three attacker sophistication levels yield four principal findings. First, IAM Canary Roles achieve the highest CAS (mean $0.450$) and Detection Resistance (DR $= 0.873$), making them the most deployable vector. Second, S3 Presigned URLs achieve the highest detection resistance (DR $= 0.890$), surviving all three cloud-native scanner models (AWS Macie, Checkov/tfsec, Prisma Cloud/Wiz). Third, ephemeral infrastructure churn degrades CAS from $\approx 0.79$ at deployment to $\approx 0.18$–$0.22$ at $48$ hours for all vectors ($p < 0.001$), establishing the first quantitative model of attribution decay in containerised environments. Fourth, Serverless Function Triggers exhibit the worst detection resistance (DR $= 0.611$) due to their explicit outbound HTTP callback pattern, motivating covert callback channel design as future work. No significant CAS difference is observed across cloud providers ($H = 1.99$, $p = 0.57$), confirming that CLOUDBURST is provider-agnostic in its effectiveness.
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Cryptography and Security
From Compression to Accountability: Harmless Copyright Protection for Dataset Distillation
Yan Liang, Ziyuan Yang, Mengyu Sun et al. (+2 more)
Large-scale
datasets have been a key driving force behind the rapid progress of deep learning, but their storage, computational, and energy costs have become increasingly prohibitive.
Dataset distillation (DD) mitigates this problem by synthesizing compact yet informative
datasets, thereby enabling efficient model training and storage. However, the ease of copying and distributing distilled
datasets introduces serious risks of copyright infringement and data leakage. Existing protection methods are primarily designed for raw
datasets rather than distilled
datasets, and typically rely on
backdoor-triggered malicious behaviors, which may raise security concerns. In this paper, we observe that deep neural networks tend to memorize subpopulation distributions during training, resulting in a systematic prediction bias, where models perform better on samples aligned with memorized subpopulations. Motivated by this observation, we propose SubPopMark, a harmless subpopulation-driven protection framework for distilled
datasets. SubPopMark consists of two stages. First, the Copyright Verification Marker(CVM) optimization stage injects a class-consistent subpopulation bias while preserving the original optimization trajectory. Second, the User-Specific Tracing Marker (USTM) optimization stage further introduces user-distinguishable perturbations into the CVM-augmented data. To enable black-box verification and tracing, we construct a reference behavior bank by collecting model outputs over carefully designed test sets that cover both standard and subpopulation-shifted data distributions. The provenance of a suspicious model is then inferred by comparing its output behavior signature with the bank and identifying the most consistent reference behavior pattern.
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All authors Yan Liang, Ziyuan Yang, Mengyu Sun, Joey Tianyi Zhou, Yi Zhang