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Computer Science Cryptography and Security

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Saturday 17 January

Cryptography and Security

Less Is More – Until It Breaks: Security Pitfalls of Vision Token Compression in Large Vision-Language Models

Visual token compression is widely adopted to improve the inference efficiency of Large Vision-Language Models (LVLMs), enabling their deployment in latency-sensitive and resource-constrained scenarios. However, existing work has mainly focused on efficiency and performance, while the security implications of visual token compression remain largely unexplored. In this work, we first reveal that visual token compression substantially degrades the robustness of LVLMs: models that are robust under uncompressed inference become highly vulnerable once compression is enabled. These vulnerabilities are state-specific; failure modes emerge only in the compressed setting and completely disappear when compression is disabled, making them particularly hidden and difficult to diagnose. By analyzing the key stages of the compression process, we identify instability in token importance ranking as the primary cause of this robustness degradation. Small and imperceptible perturbations can significantly alter token rankings, leading the compression mechanism to mistakenly discard task-critical information and ultimately causing model failure. Motivated by this observation, we propose a Compression-Aware Attack to systematically study and exploit this vulnerability. CAA directly targets the token selection mechanism and induces failures exclusively under compressed inference. We further extend this approach to more realistic black-box settings and introduce Transfer CAA, where neither the target model nor the compression configuration is accessible. We further evaluate potential defenses and find that they provide only limited protection. Extensive experiments across models, datasets, and compression methods show that visual token compression significantly undermines robustness, revealing a previously overlooked efficiency-security trade-off.
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All authors Xiaomei Zhang, Zhaoxi Zhang, Leo Yu Zhang, Yanjun Zhang, Guanhong Tao, Shirui Pan

Cryptography and Security · Cross-listed from cs.NE

Speaking to Silicon: Neural Communication with Bitcoin Mining ASICs

This definitive research memoria presents a comprehensive, mathematically verified paradigm for neural communication with Bitcoin mining Application-Specific Integrated Circuits (ASICs), integrating five complementary frameworks: thermodynamic reservoir computing, hierarchical number system theory, algorithmic analysis, network latency optimization, and machine-checked mathematical formalization. We establish that obsolete cryptocurrency mining hardware exhibits emergent computational properties enabling bidirectional information exchange between AI systems and silicon substrates. The research program demonstrates: (1) reservoir computing with NARMA-10 Normalized Root Mean Square Error (NRMSE) of 0.8661; (2) the Thermodynamic Probability Filter (TPF) achieving 92.19% theoretical energy reduction; (3) the Virtual Block Manager achieving +25% effective hashrate; and (4) hardware universality across multiple ASIC families including Antminer S9, Lucky Miner LV06, and Goldshell LB-Box. A significant contribution is the machine-checked mathematical formalization using Lean 4 and Mathlib, providing unambiguous definitions, machine-verified theorems, and reviewer-proof claims. Key theorems proven include: independence implies zero leakage, predictor beats baseline implies non-independence (the logical core of TPF), energy savings theoretical maximum, and Physical Unclonable Function (PUF) distinguishability witnesses. Vladimir Veselov's hierarchical number system theory explains why early-round information contains predictive power. This work establishes a new paradigm: treating ASICs not as passive computational substrates but as active conversational partners whose thermodynamic state encodes exploitable computational information.
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Cryptography and Security

Hybrid IDS Using Signature-Based and Anomaly-Based Detection

Intrusion detection systems (IDS) are essential for protecting computer systems and networks against a wide range of cyber threats that continue to evolve over time. IDS are commonly categorized into two main types, each with its own strengths and limitations, such as difficulty in detecting previously unseen attacks and the tendency to generate high false positive rates. This paper presents a comprehensive survey and a conceptual overview of Hybrid IDS, which integrate signature-based and anomaly-based detection techniques to enhance attack detection capabilities. The survey examines recent research on Hybrid IDS, classifies existing models into functional categories, and discusses their advantages, limitations, and application domains, including financial systems, air traffic control, and social networks. In addition, recent trends in Hybrid IDS research, such as machine learning-based approaches and cloud-based deployments, are reviewed. Finally, this work outlines potential future research directions aimed at developing more cost-effective Hybrid IDS solutions with improved ability to detect emerging and sophisticated cyberattacks.
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All authors Messaouda Boutassetta, Amina Makhlouf, Newfel Messaoudi, Abdelmadjid Benmachiche, Ines Boutabia

Cryptography and Security

MongoDB Injection Query Classification Model using MongoDB Log files as Training Data

NoSQL Injection attacks are a class of cybersecurity attacks where an attacker sends a specifically engineered query to a NoSQL database which then performs an unauthorized operation. To defend against such attacks, rule based systems were initially developed but then were found to be ineffective to innovative injection attacks hence a model based approach was developed. Most model based detection systems, during testing gave exponentially positive results but were trained only on the query statement sent to the server. However due to the scarcity of data and class imbalances these model based systems were found to be not effective against all attacks in the real world. This paper explores classifying NoSQL injection attacks sent to a MongoDB server based on Log Data, and other extracted features excluding raw query statements. The log data was collected from a simulated attack on an empty MongoDB server which was then processed and explored. A discriminant analysis was carried out to determine statistically significant features to discriminate between injection and benign queries resulting in a dataset of significant features. Several Machine learning based classification models using an AutoML library, "FLAML", as well as 6 manually programmed models were trained on this dataset , which were then trained on 50 randomized samples of data, cross validated and evaluated. The study found that the best model was the "FLAML" library's "XGBoost limited depth" model with an accuracy of 71%.
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Cryptography and Security · Cross-listed from cs.SE

Enhancing Fuzz Testing Efficiency through Automated Fuzz Target Generation

Fuzzing continues to be the most effective method for identifying security vulnerabilities in software. In the context of fuzz testing, the fuzzer supplies varied inputs to fuzz targets, which are designed to comprehensively exercise critical sections of the client code. Various studies have focused on optimizing and developing advanced fuzzers, such as AFL++, libFuzzer, Honggfuzz, syzkaller, ISP-Fuzzer, which have substantially enhanced vulnerability detection in widely used software and libraries. Nevertheless, achieving greater coverage necessitates improvements in both the quality and quantity of fuzz targets. In large-scale software projects and libraries – characterized by numerous user defined functions and data types – manual creation of fuzz targets is both labor-intensive and time-consuming. This challenge underscores the need for automated techniques not only to generate fuzz targets but also to streamline the execution and analysis of their results. In this paper, we introduce an approach to improving fuzz target generation through static analysis of library source code. The proposed method encompasses several key aspects: it analyzes source code structures to accurately construct function calls and generate fuzz targets; it maps fuzzer input data to the corresponding function parameters; it synthesizes compilation information for the fuzz targets; and it automatically collects and analyzes execution results. Our findings are demonstrated through the application of this approach to the generation of fuzz targets for C/C++ libraries.
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Cryptography and Security

Taming Various Privilege Escalation in LLM-Based Agent Systems: A Mandatory Access Control Framework

Large Language Model (LLM)-based agent systems are increasingly deployed for complex real-world tasks but remain vulnerable to natural language-based attacks that exploit over-privileged tool use. This paper aims to understand and mitigate such attacks through the lens of privilege escalation, defined as agent actions exceeding the least privilege required for a user's intended task. Based on a formal model of LLM agent systems, we identify novel privilege escalation scenarios, particularly in multi-agent systems, including a variant akin to the classic confused deputy problem. To defend against both known and newly demonstrated privilege escalation, we propose SEAgent, a mandatory access control (MAC) framework built upon attribute-based access control (ABAC). SEAgent monitors agent-tool interactions via an information flow graph and enforces customizable security policies based on entity attributes. Our evaluations show that SEAgent effectively blocks various privilege escalation while maintaining a low false positive rate and negligible system overhead. This demonstrates its robustness and adaptability in securing LLM-based agent systems.
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All authors Zimo Ji, Daoyuan Wu, Wenyuan Jiang, Pingchuan Ma, Zongjie Li, Yudong Gao, Shuai Wang, Yingjiu Li

Cryptography and Security

SimFuzz: Similarity-guided Block-level Mutation for RISC-V Processor Fuzzing

The Instruction Set Architecture (ISA) defines processor operations and serves as the interface between hardware and software. As an open ISA, RISC-V lowers the barriers to processor design and encourages widespread adoption, but also exposes processors to security risks such as functional bugs. Processor fuzzing is a powerful technique for automatically detecting these bugs. However, existing fuzzing methods suffer from two main limitations. First, their emphasis on redundant test case generation causes them to overlook cross-processor corner cases. Second, they rely too heavily on coverage guidance. Current coverage metrics are biased and inefficient, and become ineffective once coverage growth plateaus. To overcome these limitations, we propose SimFuzz, a fuzzing framework that constructs a high-quality seed corpus from historical bug-triggering inputs and employs similarity-guided, block-level mutation to efficiently explore the processor input space. By introducing instruction similarity, SimFuzz expands the input space around seeds while preserving control-flow structure, enabling deeper exploration without relying on coverage feedback. We evaluate SimFuzz on three widely used open-source RISC-V processors: Rocket, BOOM, and XiangShan, and discover 17 bugs in total, including 14 previously unknown issues, 7 of which have been assigned CVE identifiers. These bugs affect the decode and memory units, cause instruction and data errors, and can lead to kernel instability or system crashes. Experimental results show that SimFuzz achieves up to 73.22% multiplexer coverage on the high-quality seed corpus. Our findings highlight critical security bugs in mainstream RISC-V processors and offer actionable insights for improving functional verification.
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All authors Hao Lyu, Jingzheng Wu, Xiang Ling, Yicheng Zhong, Zhiyuan Li, Tianyue Luo

Friday 16 January

Cryptography and Security

Predicting Tail-Risk Escalation in IDS Alert Time Series

Network defenders face a steady stream of attacks, observed as raw Intrusion Detection System (IDS) alerts. The sheer volume of alerts demands prioritization, typically based on high-level risk classifications. This work expands the scope of risk measurement by examining alerts not only through their technical characteristics but also by examining and classifying their temporal patterns. One critical issue in responding to intrusion alerts is determining whether an alert is part of an escalating attack pattern or an opportunistic scan. To identify the former, we apply extreme-regime forecasting methods from financial modeling to IDS data. Extreme-regime forecasting is designed to identify likely future high-impact events or significant shifts in system behavior. Using these methods, we examine attack patterns by computing per-minute alert intensity, volatility, and a short-term momentum measure derived from weighted moving averages. We evaluate the efficacy of a supervised learning model for forecasting future escalation patterns using these derived features. The trained model identifies future high-intensity attacks and demonstrates strong predictive performance, achieving approximately 91% accuracy, 89% recall, and 98% precision. Our contributions provide a temporal measurement framework for identifying future high-intensity attacks and demonstrate the presence of predictive early-warning signals within the temporal structure of IDS alert streams. We describe our methods in sufficient detail to enable reproduction using other IDS datasets. In addition, we make the trained models openly available to support further research. Finally, we introduce an interpretable visualization that enables defenders to generate early predictive warnings of elevated volumetric arrival risk.
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Cryptography and Security

Guardrails for trust, safety, and ethical development and deployment of Large Language Models (LLM)

The AI era has ushered in Large Language Models (LLM) to the technological forefront, which has been much of the talk in 2023, and is likely to remain as such for many years to come. LLMs are the AI models that are the power house behind generative AI applications such as ChatGPT. These AI models, fueled by vast amounts of data and computational prowess, have unlocked remarkable capabilities, from human-like text generation to assisting with natural language understanding (NLU) tasks. They have quickly become the foundation upon which countless applications and software services are being built, or at least being augmented with. However, as with any groundbreaking innovations, the rise of LLMs brings forth critical safety, privacy, and ethical concerns. These models are found to have a propensity to leak private information, produce false information, and can be coerced into generating content that can be used for nefarious purposes by bad actors, or even by regular users unknowingly. Implementing safeguards and guardrailing techniques is imperative for applications to ensure that the content generated by LLMs are safe, secure, and ethical. Thus, frameworks to deploy mechanisms that prevent misuse of these models via application implementations is imperative. In this study, wepropose a Flexible Adaptive Sequencing mechanism with trust and safety modules, that can be used to implement safety guardrails for the development and deployment of LLMs.
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Cryptography and Security

ARM MTE Performance in Practice (Extended Version)

We present the first comprehensive analysis of ARM MTE hardware performance on four different microarchitectures: ARM Big (A7x), Little (A5x), and Performance (Cortex-X) cores on the Google Pixel 8 and Pixel 9, and on Ampere Computing's AmpereOne CPU core. We also include preliminary analysis of MTE on Apple's M5 chip. We investigate performance in MTE's primary application – probabilistic memory safety – on both SPEC CPU benchmarks and in server workloads such as RocksDB, Nginx, PostgreSQL, and Memcached. While MTE often exhibits modest overheads, we also see performance slowdowns up to 6.64x on certain benchmarks. We identify the microarchitectural cause of these overheads and where they can be addressed in future processors. We then analyze MTE's performance for more specialized security applications such as memory tracing, time-of-check time-of-use prevention, sandboxing, and CFI. In some of these cases, MTE offers significant advantages today, while the benefits for other cases are negligible or will depend on future hardware. Finally, we explore where prior work characterizing MTE performance has either been incomplete or incorrect due to methodological or experimental errors.
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All authors Taehyun Noh, Yingchen Wang, Tal Garfinkel, Mahesh Madhav, Daniel Moghimi, Mattan Erez, Shravan Narayan

Cryptography and Security · Cross-listed from cs.AR

NuRedact: Non-Uniform eFPGA Architecture for Low-Overhead and Secure IP Redaction

While logic locking has been extensively studied as a countermeasure against integrated circuit (IC) supply chain threats, recent research has shifted toward reconfigurable-based redaction techniques, e.g., LUT- and eFPGA-based schemes. While these approaches raise the bar against attacks, they incur substantial overhead, much of which arises not from genuine functional reconfigurability need, but from artificial complexity intended solely to frustrate reverse engineering (RE). As a result, fabrics are often underutilized, and security is achieved at disproportionate cost. This paper introduces NuRedact, the first full-custom eFPGA redaction framework that embraces architectural non-uniformity to balance security and efficiency. Built as an extension of the widely adopted OpenFPGA infrastructure, NuRedact introduces a three-stage methodology: (i) custom fabric generation with pin-mapping irregularity, (ii) VPR-level modifications to enable non-uniform placement guided by an automated Python-based optimizer, and (iii) redaction-aware reconfiguration and mapping of target IP modules. Experimental results show up to 9x area reduction compared to conventional uniform fabrics, achieving competitive efficiency with LUT-based and even transistor-level redaction techniques while retaining strong resilience. From a security perspective, NuRedact fabrics are evaluated against state-of-the-art attack models, including SAT-based, cyclic, and sequential variants, and show enhanced resilience while maintaining practical design overheads.
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Cryptography and Security

DROIDCCT: Cryptographic Compliance Test via Trillion-Scale Measurement

We develop DroidCCT, a distributed test framework to evaluate the scale of a wide range of failures/bugs in cryptography for end users. DroidCCT relies on passive analysis of artifacts from the execution of cryptographic operations in the Android ecosystem to identify weak implementations. We collect trillions of samples from cryptographic operations of Android Keystore on half a billion devices and apply severalanalysis techniques to evaluate the quality of cryptographic output from these devices and their underlying implementations. Our study reveals several patterns of bugs and weakness in cryptographic implementations from various manufacturers and chipsets. We show that the heterogeneous nature of cryptographic implementations results in non-uniform availability and reliability of various cryptographic functions. More importantly, flaws such as the use of weakly-generated random parameters, and timing side channels may surface across deployments of cryptography. Our results highlight the importance of fault- and side-channel-resistant cryptography and the ability to transparently and openly test these implementations.
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All authors Daniel Moghimi, Alexandru-Cosmin Mihai, Borbala Benko, Catherine Vlasov, Elie Bursztein, Kurt Thomas, Laszlo Siroki, Pedro Barbosa, Remi Audebert

Cryptography and Security

On Abnormal Execution Timing of Conditional Jump Instructions

An extensive line of work on modern computing architectures has shown that the execution time of instructions can (i) depend on the operand of the instruction or (ii) be influenced by system optimizations, e.g., branch prediction and speculative execution paradigms. In this paper, we systematically measure and analyze timing variabilities in conditional jump instructions that can be macro-fused with a preceding instruction, depending on their placement within the binary. Our measurements indicate that these timing variations stem from the micro-op cache placement and the jump's offset in the L1 instruction cache of modern processors. We demonstrate that this behavior is consistent across multiple microarchitectures, including Skylake, Coffee Lake, and Kaby Lake, as well as various real-world implementations. We confirm the prevalence of this variability through extensive experiments on a large-scale set of popular binaries, including libraries from Ubuntu 24.04, Windows 10 Pro, and several open-source cryptographic libraries. We also show that one can easily avoid this timing variability by ensuring that macro-fusible instructions are 32-byte aligned - an approach initially suggested in 2019 by Intel in an overlooked short report. We quantify the performance impact of this approach across the cryptographic libraries, showing a speedup of 2.15% on average (and up to 10.54%) when avoiding the timing variability. As a by-product, we show that this variability can be exploited as a covert channel, achieving a maximum throughput of 16.14 Mbps.
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All authors Annika Wilde, Samira Briongos, Claudio Soriente, Ghassan Karame

Cryptography and Security

Attesting Model Lineage by Consisted Knowledge Evolution with Fine-Tuning Trajectory

The fine-tuning technique in deep learning gives rise to an emerging lineage relationship among models. This lineage provides a promising perspective for addressing security concerns such as unauthorized model redistribution and false claim of model provenance, which are particularly pressing in \textcolor{blue}{open-weight model} libraries where robust lineage verification mechanisms are often lacking. Existing approaches to model lineage detection primarily rely on static architectural similarities, which are insufficient to capture the dynamic evolution of knowledge that underlies true lineage relationships. Drawing inspiration from the genetic mechanism of human evolution, we tackle the problem of model lineage attestation by verifying the joint trajectory of knowledge evolution and parameter modification. To this end, we propose a novel model lineage attestation framework. In our framework, model editing is first leveraged to quantify parameter-level changes introduced by fine-tuning. Subsequently, we introduce a novel knowledge vectorization mechanism that refines the evolved knowledge within the edited models into compact representations by the assistance of probe samples. The probing strategies are adapted to different types of model families. These embeddings serve as the foundation for verifying the arithmetic consistency of knowledge relationships across models, thereby enabling robust attestation of model lineage. Extensive experimental evaluations demonstrate the effectiveness and resilience of our approach in a variety of adversarial scenarios in the real world. Our method consistently achieves reliable lineage verification across a broad spectrum of model types, including classifiers, diffusion models, and large language models.
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All authors Zhuoyi Shang, Jiasen Li, Pengzhen Chen, Yanwei Liu, Xiaoyan Gu, Weiping Wang

Cryptography and Security

A Survey on Mapping Digital Systems with Bill of Materials: Development, Practices, and Challenges

Modern digital ecosystems, spanning software, hardware, learning models, datasets, and cryptographic products, continue to grow in complexity, making it difficult for organizations to understand and manage component dependencies. Bills of Materials (BOMs) have emerged as a structured way to document product components, their interrelationships, and key metadata, improving visibility and security across digital supply chains. This survey provides the first comprehensive cross-domain review of BOM developments and practices. We start by examining the evolution of BOM frameworks in three stages (i.e., pre-development, initial, and accelerated) and summarizing their core principles, key stakeholders, and standardization efforts for hardware, software, artificial intelligence (AI) models, datasets, and cryptographic assets. We then review industry practices for generating BOM data, evaluating its quality, and securely sharing it. Next, we review practical downstream uses of BOM data, including dependency modeling, compliance verification, operational risk assessment, and vulnerability tracking. We also discuss academic efforts to address limitations in current BOM frameworks through refinements, extensions, or new models tailored to emerging domains such as data ecosystems and AI supply chains. Finally, we identify four key gaps that limit the usability and reliability of today's BOM frameworks, motivating future research directions.
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Cryptography and Security

IMS: Intelligent Hardware Monitoring System for Secure SoCs

In the modern Systems-on-Chip (SoC), the Advanced eXtensible Interface (AXI) protocol exhibits security vulnerabilities, enabling partial or complete denial-of-service (DoS) through protocol-violation attacks. The recent countermeasures lack a dedicated real-time protocol semantic analysis and evade protocol compliance checks. This paper tackles this AXI vulnerability issue and presents an intelligent hardware monitoring system (IMS) for real-time detection of AXI protocol violations. IMS is a hardware module leveraging neural networks to achieve high detection accuracy. For model training, we perform DoS attacks through header-field manipulation and systematic malicious operations, while recording AXI transactions to build a training dataset. We then deploy a quantization-optimized neural network, achieving 98.7% detection accuracy with <=3% latency overhead, and throughput of >2.5 million inferences/s. We subsequently integrate this IMS into a RISC-V SoC as a memory-mapped IP core to monitor its AXI bus. For demonstration and initial assessment for later ASIC integration, we implemented this IMS on an AMD Zynq UltraScale+ MPSoC ZCU104 board, showing an overall small hardware footprint (9.04% look-up-tables (LUTs), 0.23% DSP slices, and 0.70% flip-flops) and negligible impact on the overall design's achievable frequency. This demonstrates the feasibility of lightweight, security monitoring for resource-constrained edge environments.
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All authors Wadid Foudhaili, Aykut Rencber, Anouar Nechi, Rainer Buchty, Mladen Berekovic, Andres Gomez, Saleh Mulhem

Cryptography and Security

Understanding Help Seeking for Digital Privacy, Safety, and Security

The complexity of navigating digital privacy, safety, and security threats often falls directly on users. This leads to users seeking help from family and peers, platforms and advice guides, dedicated communities, and even large language models (LLMs). As a precursor to improving resources across this ecosystem, our community needs to understand what help seeking looks like in the wild. To that end, we blend qualitative coding with LLM fine-tuning to sift through over one billion Reddit posts from the last four years to identify where and for what users seek digital privacy, safety, or security help. We isolate three million relevant posts with 93% precision and recall and automatically annotate each with the topics discussed (e.g., security tools, privacy configurations, scams, account compromise, content moderation, and more). We use this dataset to understand the scope and scale of help seeking, the communities that provide help, and the types of help sought. Our work informs the development of better resources for users (e.g., user guides or LLM help-giving agents) while underscoring the inherent challenges of supporting users through complex combinations of threats, platforms, mitigations, context, and emotions.
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All authors Kurt Thomas, Sai Teja Peddinti, Sarah Meiklejohn, Tara Matthews, Amelia Hassoun, Animesh Srivastava, Jessica McClearn, Patrick Gage Kelley, Sunny Consolvo, Nina Taft

Cryptography and Security

InterPUF: Distributed Authentication via Physically Unclonable Functions and Multi-party Computation for Reconfigurable Interposers

Modern system-in-package (SiP) platforms increasingly adopt reconfigurable interposers to enable plug-and-play chiplet integration across heterogeneous multi-vendor ecosystems. However, this flexibility introduces severe trust challenges, as traditional authentication schemes fail to scale or adapt in decentralized, post-fabrication programmable environments. This paper presents InterPUF, a compact and scalable authentication framework that transforms the interposer into a distributed root of trust. InterPUF embeds a route-based differential delay physically unclonable function (PUF) across the reconfigurable interconnect and secures authentication using multi-party computation (MPC), ensuring raw PUF signatures are never exposed. Our hardware evaluation shows only 0.23% area and 0.072% power overhead across diverse chiplets while preserving authentication latency within tens of nanoseconds. Simulation results using pyPUF confirm strong uniqueness, reliability, and modeling resistance under process, voltage, and temperature variations. By combining interposer-resident PUF primitives with cryptographic hashing and collaborative verification, InterPUF enforces a minimal-trust authentication model without relying on a centralized anchor.
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Cryptography and Security

VidLeaks: Membership Inference Attacks Against Text-to-Video Models

The proliferation of powerful Text-to-Video (T2V) models, trained on massive web-scale datasets, raises urgent concerns about copyright and privacy violations. Membership inference attacks (MIAs) provide a principled tool for auditing such risks, yet existing techniques - designed for static data like images or text - fail to capture the spatio-temporal complexities of video generation. In particular, they overlook the sparsity of memorization signals in keyframes and the instability introduced by stochastic temporal dynamics. In this paper, we conduct the first systematic study of MIAs against T2V models and introduce a novel framework VidLeaks, which probes sparse-temporal memorization through two complementary signals: 1) Spatial Reconstruction Fidelity (SRF), using a Top-K similarity to amplify spatial memorization signals from sparsely memorized keyframes, and 2) Temporal Generative Stability (TGS), which measures semantic consistency across multiple queries to capture temporal leakage. We evaluate VidLeaks under three progressively restrictive black-box settings - supervised, reference-based, and query-only. Experiments on three representative T2V models reveal severe vulnerabilities: VidLeaks achieves AUC of 82.92% on AnimateDiff and 97.01% on InstructVideo even in the strict query-only setting, posing a realistic and exploitable privacy risk. Our work provides the first concrete evidence that T2V models leak substantial membership information through both sparse and temporal memorization, establishing a foundation for auditing video generation systems and motivating the development of new defenses. Code is available at: https://zenodo.org/records/17972831.
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All authors Li Wang, Wenyu Chen, Ning Yu, Zheng Li, Shanqing Guo

Cryptography and Security

LoRA as Oracle

Practitioners increasingly deploy neural networks they did not train, and must audit them after the fact for hidden backdoors, without the training pipeline, the poisoned data, or knowledge of any trigger. We introduce a low-rank auditing lens built on a single observation: what a model has internalized and how it behaves are distinct axes that can diverge. Fitting a small low-rank adapter toward a hypothesis and reading the geometry of the resulting update, its energy relative to, and its alignment with, the frozen weights, measures internalization directly, independently of the model's output behavior. The lens earns its value where the two axes diverge: a backdoor is malicious internalization, a learned trigger-to-target shortcut, that behavioral auditing can miss. Reading it, we identify the backdoor's target class label-free and without any triggered data when the backdoor leaves a legible internalization signature, then erase the identified shortcut within the same low-rank subspace, uniquely coupling detection confidence to the size of the repair. Across four datasets and four architectures, our lens is the most consistent target identifier among defenses in its threat model; its rank-r repair removes backdoors while preserving clean accuracy where full-model baselines collapse it, at orders-of-magnitude lower parameter and memory cost; and it is the only method that both erases the backdoor and leaves a benign model intact, because it can decline to act when uncertain.
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Cryptography and Security

SD-RAG: A Prompt-Injection-Resilient Framework for Selective Disclosure in Retrieval-Augmented Generation

Retrieval-Augmented Generation (RAG) has attracted significant attention due to its ability to combine the generative capabilities of Large Language Models (LLMs) with knowledge obtained through efficient retrieval mechanisms over large-scale data collections. Currently, the majority of existing approaches overlook the risks associated with exposing sensitive or access-controlled information directly to the generation model. Only a few approaches propose techniques to instruct the generative model to refrain from disclosing sensitive information; however, recent studies have also demonstrated that LLMs remain vulnerable to prompt injection attacks that can override intended behavioral constraints. For these reasons, we propose a novel approach to Selective Disclosure in Retrieval-Augmented Generation, called SD-RAG, which decouples the enforcement of security and privacy constraints from the generation process itself. Rather than relying on prompt-level safeguards, SD-RAG applies sanitization and disclosure controls during the retrieval phase, prior to augmenting the language model's input. Moreover, we introduce a semantic mechanism to allow the ingestion of human-readable dynamic security and privacy constraints together with an optimized graph-based data model that supports fine-grained, policy-aware retrieval. Our experimental evaluation demonstrates the superiority of SD-RAG over baseline existing approaches, achieving up to a $58\%$ improvement in the privacy score, while also showing a strong resilience to prompt injection attacks targeting the generative model.
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Cryptography and Security

Proving Circuit Functional Equivalence in Zero Knowledge

The modern integrated circuit ecosystem is increasingly reliant on third-party intellectual property integration, which introduces security risks, including hardware Trojans and security vulnerabilities. Addressing the resulting trust deadlock between IP vendors and system integrators without exposing proprietary designs requires novel privacy-preserving verification techniques. However, existing privacy-preserving hardware verification methods are all simulation-based and fail to offer formal guarantees. In this paper, we propose ZK-CEC, the first privacy-preserving framework for hardware formal verification. By combining formal verification and zero-knowledge proof (ZKP), ZK-CEC establishes a foundation for formally verifying IP correctness and security without compromising the confidentiality of the designs. We observe that existing zero-knowledge protocols for formal verification are designed to prove statements of public formulas. However, in a privacy-preserving verification context where the formula is secret, these protocols cannot prevent a malicious prover from forging the formula, thereby compromising the soundness of the verification. To address these gaps, we first propose a blueprint for proving the unsatisfiability of a secret design against a public constraint, which is widely applicable to proving properties in software, hardware, and cyber-physical systems. Based on the proposed blueprint, we construct ZK-CEC, which enables a prover to convince the verifier that a secret IP's functionality aligns perfectly with the public specification in zero knowledge, revealing only the length and width of the proof. We implement ZK-CEC and evaluate its performance across various circuits, including arithmetic units and cryptographic components. Experimental results show that ZK-CEC successfully verifies practical designs, such as the AES S-Box, within practical time limits.
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Cryptography and Security

A Defender-Attacker-Defender Model for Optimizing the Resilience of Hospital Networks to Cyberattacks

Considering the increasing frequency of cyberattacks affecting multiple hospitals simultaneously, improving resilience at a network level is essential. Various countermeasures exist to improve resilience against cyberattacks, such as deploying controls that strengthen IT infrastructures to limit their impact, or enabling resource sharing, patient transfers and backup capacities to maintain services of hospitals in response to realized attacks. However, determining the most cost-effective combination among these wide range of countermeasures is a complex challenge, further intensified by constrained budgets and competing priorities between maintaining efficient daily hospital operations and investing in disaster preparedness. To address these challenges, we propose a defender-attacker-defender optimization model that supports decision-makers in identifying effective strategies for improving the resilience of a network of hospitals against cyberattacks. The model explicitly captures interdependence between hospital services and their supporting IT infrastructures. By doing so, cyberattacks can be directly translated into reductions of service capacities, which allows to assess proactive and reactive strategies on both the operational and technical sides within a single framework. Further, time-dependent resilience measures are incorporated as design objectives to account for the mid- to long-term consequences of cyberattacks. The model is validated based on the German hospital network, suggesting that enabling cooperation with backup capacities particularly in urban areas, alongside strengthening of IT infrastructures across all hospitals, are crucial strategies.
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Cryptography and Security · Cross-listed from cs.LG

Differentially Private Subspace Fine-Tuning for Large Language Models

Fine-tuning large language models on downstream tasks is crucial for realizing their cross-domain potential but often relies on sensitive data, raising privacy concerns. Differential privacy (DP) offers rigorous privacy guarantees and has been widely adopted in fine-tuning; however, naively injecting noise across the high-dimensional parameter space creates perturbations with large norms, degrading performance and destabilizing training. To address this issue, we propose DP-SFT, a two-stage subspace fine-tuning method that substantially reduces noise magnitude while preserving formal DP guarantees. Our intuition is that, during fine-tuning, significant parameter updates lie within a low-dimensional, task-specific subspace, while other directions change minimally. Hence, we only inject DP noise into this subspace to protect privacy without perturbing irrelevant parameters. In phase one, we identify the subspace by analyzing principal gradient directions to capture task-specific update signals. In phase two, we project full gradients onto this subspace, add DP noise, and map the perturbed gradients back to the original parameter space for model updates, markedly lowering noise impact. Experiments on multiple datasets demonstrate that DP-SFT enhances accuracy and stability under rigorous DP constraints, accelerates convergence, and achieves substantial gains over DP fine-tuning baselines.
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All authors Lele Zheng, Xiang Wang, Tao Zhang, Yang Cao, Ke Cheng, Yulong Shen

Cryptography and Security

Shaping a Quantum-Resistant Future: Strategies for Post-Quantum PKI

As the quantum computing era approaches, securing classical cryptographic protocols becomes imperative. Public key cryptography is widely used for signature and key exchange but it is the type of cryptography more threatened by quantum computing. Its application typically requires support via a public-key certificate, which is a signed data structure and must therefore face twice the quantum challenge: for the certified keys and for the signature itself. We present the latest developments in selecting robust Post-Quantum algorithms and investigate their applicability in the Public Key Infrastructure context. Our contribution entails defining requirements for a secure transition to a quantum-resistant Public Key Infrastructure, with a focus on adaptations for the X.509 certificate format. Additionally, we explore transitioning Certificate Revocation List and Online Certificate Status Protocol to support quantum-resistant algorithms. Through comparative analysis, we elucidate the complex transition to a quantum-resistant PKI.
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Cryptography and Security

Towards Quantum-Resistant Trusted Computing: Architectures for Post-Quantum Integrity Verification Techniques

Trust is the core building block of secure systems, and it is enforced through methods to ensure that a specific system is properly configured and works as expected. In this context, a Root of Trust (RoT) establishes a trusted environment, where both data and code are authenticated via a digital signature based on asymmetric cryptography, which is vulnerable to the threat posed by Quantum Computers (QCs). Firmware, being the first layer of trusted software, faces unique risks due to its longevity and difficult update. The transition of firmware protection to Post-Quantum Cryptography (PQC) is urgent, since it reduces the risk derived from exposing all computing and network devices to quantum-based attacks. This paper offers an analysis of the most common trust techniques and their roadmap towards a Post-Quantum (PQ) world, by investigating the current status of PQC and the challenges posed by such algorithms in existing Trusted Computing (TC) solutions from an integration perspective. Furthermore, this paper proposes an architecture for TC techniques enhanced with PEC, addressing the imperative for immediate adoption of quantum-resistant algorithms.
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Cryptography and Security

AJAR: Adaptive Jailbreak Architecture for Red-teaming

Large language model (LLM) safety evaluation is moving from content moderation to action security as modern systems gain persistent state, tool access, and autonomous control loops. Existing jailbreak frameworks still leave a gap between adaptive multi-turn attacks and agentic runtimes: attack algorithms are usually packaged as monolithic scripts, while agent harnesses rarely expose explicit abstractions for rollback, tool simulation, or strategy switching. We present AJAR, a red-teaming framework that exposes multi-turn jailbreak algorithms as callable MCP services and lets an Auditor Agent orchestrate them inside a tool-aware runtime built on Petri. AJAR integrates three representative attacks, namely Crescendo, ActorAttack, and X-Teaming, under a shared service interface for planning, prompt generation, optimization, evaluation, and context control. On 200 HarmBench validation behaviors, AJAR improves X-Teaming from 65.0% to 76.0% attack success rate (ASR), reaches 80% cumulative success one turn earlier than the native implementation, and reproduces Crescendo more effectively than PyRIT (91.0% vs. 87.5% ASR). Behavior-level analysis shows that these gains are concentrated in hard categories and frequently depend on rollback-enabled transcript repair. We further show that tool access reshapes rather than uniformly enlarges the attack surface: ActorAttack rises from 51.0% to 56.0% ASR with tools, whereas Crescendo drops from 91.0% to 78.0% and X-Teaming from 76.0% to 55.5%, with the sharpest declines appearing in categories that rely on long semantic buildup. These results position AJAR as a practical foundation for evaluating multi-turn jailbreaks under realistic agent constraints. Code and data are available at https://github.com/douyipu/ajar.
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Cryptography and Security

Beyond Max Tokens: Stealthy Resource Amplification via Tool Calling Chains in LLM Agents

The agent–tool interaction loop is a critical attack surface for modern Large Language Model (LLM) agents. Existing denial-of-service (DoS) attacks typically function at the user-prompt or retrieval-augmented generation (RAG) context layer and are inherently single-turn in nature. This limitation restricts cost amplification and diminishes stealth in goal-oriented workflows. To address these issues, we proposed a stealthy, multi-turn economic DoS attack at the tool layer under the Model Context Protocol (MCP). By simply editing text-visible fields and implementing a template-driven return policy, our malicious server preserves function signatures and the terminal benign payload while steering agents into prolonged, verbose tool-calling chains. We optimize these text-only edits with Monte Carlo Tree Search (MCTS) to maximize cost under a task-success constraint. Across six LLMs on ToolBench and BFCL benchmarks, our attack yields trajectories over 60K tokens, increases per-query cost by up to 658 times, raises energy by 100 to 560 times, and pushes GPU key-value (KV) cache occupancy to 35–74%. Standard prompt filters and output trajectory monitors seldom detect these attacks, highlighting the need for defenses that safeguard agentic processes rather than focusing solely on final outcomes. We will release the code soon.
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All authors Kaiyu Zhou, Yongsen Zheng, Yicheng He, Meng Xue, Xueluan Gong, Yuji Wang, Xuanye Zhang, Kwok-Yan Lam

Cryptography and Security

Secure Data Bridging in Industry 4.0: An OPC UA Aggregation Approach for Including Insecure Legacy Systems

The increased connectivity of industrial networks has led to a surge in cyberattacks, emphasizing the need for cybersecurity measures tailored to the specific requirements of industrial systems. Modern Industry 4.0 technologies, such as OPC UA, offer enhanced resilience against these threats. However, widespread adoption remains limited due to long installation times, proprietary technology, restricted flexibility, and formal process requirements (e.g. safety certifications). Consequently, many systems do not yet implement these technologies, or only partially. This leads to the challenge of dealing with so-called brownfield systems, which are often placed in isolated security zones to mitigate risks. However, the need for data exchange between secure and insecure zones persists. This paper reviews existing solutions to address this challenge by analysing their approaches, advantages, and limitations. Building on these insights, we identify three key concepts, evaluate their suitability and compatibility, and ultimately introduce the SigmaServer, a novel TCP-level aggregation method. The developed proof-of-principle implementation is evaluated in an operational technology (OT) testbed, demonstrating its applicability and effectiveness in bridging secure and insecure zones.
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All authors Dalibor Sain, Thomas Rosenstatter, Olaf Saßnick, Christian Schäfer, Stefan Huber

Cryptography and Security

Hidden-in-Plain-Text: A Benchmark for Social-Web Indirect Prompt Injection in RAG

Retrieval-augmented generation (RAG) systems put more and more emphasis on grounding their responses in user-generated content found on the Web, amplifying both their usefulness and their attack surface. Most notably, indirect prompt injection and retrieval poisoning attack the web-native carriers that survive ingestion pipelines and are very concerning. We provide OpenRAG-Soc, a compact, reproducible benchmark-and-harness for web-facing RAG evaluation under these threats, in a discrete data package. The suite combines a social corpus with interchangeable sparse and dense retrievers and deployable mitigations - HTML/Markdown sanitization, Unicode normalization, and attribution-gated answered. It standardizes end-to-end evaluation from ingestion to generation and reports attacks time of one of the responses at answer time, rank shifts in both sparse and dense retrievers, utility and latency, allowing for apples-to-apples comparisons across carriers and defenses. OpenRAG-Soc targets practitioners who need fast, and realistic tests to track risk and harden deployments.
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