Cryptography and Security · Cross-listed from cs.DC
It's Not Just Timestamps: A Study on Docker Reproducibility
Oreofe Solarin
Reproducible container builds promise a simple integrity check for software supply chains: rebuild an image from its Dockerfile and compare hashes. We build a Docker measurement pipeline and apply it to a stratified sample of 2,000 GitHub repositories that contained a Dockerfile. We found that only 56% produce any buildable image, and just 2.7% of those are bitwise reproducible without any infrastructure configurations. After modifying infrastructure configurations, we raise bitwise reproducibility by 18.6%, but 78.7% of buildable Dockerfiles remain non-reproducible. We analyze the root causes of the remaining differences, and find that beyond timestamps and metadata, developer-controlled choices such as uncleaned caches, logs, documentation, and floating versions are dominant causes of non-reproducibility. We derive concrete Dockerfile guidelines from these patterns and discuss how they can inform future linters and Continuous Integration (CI) checks for reproducible containers.
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Cryptography and Security
Phantom Transfer: Data Poisoning can Survive Data-Level Defences
Andrew Draganov, Tolga H. Dur, Anandmayi Bhongade et al. (+1 more)
We present a data poisoning attack – Phantom Transfer – with the property that, even if you know precisely how the poison was placed into an otherwise benign
dataset, you cannot filter it out. We achieve this by modifying subliminal learning to work in real-world contexts and demonstrate that the attack works regardless of which model produced the data, which model is trained on the data or what the attack target is. Furthermore, the attack survives 11 tested data-level defences, including one where every sample is paraphrased by another model. We characterise when this attack works best and show that it can be used to plant password-triggered behaviours into models while still beating defences. We suggest that future defences should be supplemented with white-box methods and post-training model audits.
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All authors Andrew Draganov, Tolga H. Dur, Anandmayi Bhongade, Mary Phuong
Cryptography and Security
Semantic-level Backdoor Attack against Text-to-Image Diffusion Models
Tianxin Chen, Wenbo Jiang, Hongqiao Chen et al. (+2 more)
Text-to-image (T2I)
diffusion models are widely adopted for their strong generative capabilities, yet remain vulnerable to
backdoor attacks. Existing attacks typically rely on fixed textual triggers and single-entity
backdoor targets, making them highly susceptible to enumeration-based input defenses and
attention-consistency detection. In this work, we propose Semantic-level
Backdoor Attack (SemBD), which introduces representation-level triggers based on continuous semantic regions rather than discrete textual patterns. SemBD implants such semantic
backdoors by
distillation-based editing of the key and value projection
matrices in cross-
attention layers, enabling semantically equivalent but textually diverse
prompts to activate the
backdoor. To further enhance stealthiness, SemBD incorporates a semantic regularization to prevent unintended activation under incomplete semantics, as well as multi-entity
backdoor targets that avoid highly consistent cross-
attention patterns. Extensive experiments demonstrate that SemBD achieves a 100% attack success rate while maintaining strong robustness against state-of-the-art input-level defenses. Our code is available at https://github.com/DPAS-Lab/SemBD/.
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All authors Tianxin Chen, Wenbo Jiang, Hongqiao Chen, Zhirun Zheng, Cheng Huang
Cryptography and Security
Steering Externalities: Benign Activation Steering Unintentionally Increases Jailbreak Risk for Large Language Models
Chen Xiong, Zhiyuan He, Pin-Yu Chen et al. (+2 more)
Activation steering is a practical post-training model
alignment technique to enhance the utility of Large
Language Models (LLMs). Prior to deploying a model as a service, developers can steer a pre-trained model toward specific behavioral objectives, such as compliance or instruction adherence, without the need for retraining. This process is as simple as adding a steering vector to the model's internal representations. However, this capability unintentionally introduces critical and under-explored safety risks. We identify a phenomenon termed Steering Externalities, where steering vectors derived from entirely benign
datasets-such as those enforcing strict compliance or specific output formats like JSON-inadvertently erode safety guardrails. Experiments reveal that these interventions act as a force multiplier, creating new vulnerabilities to jailbreaks and increasing attack success rates to over 80% on standard
benchmarks by bypassing the initial safety
alignment. Ultimately, our results expose a critical blind spot in deployment: benign activation steering systematically erodes the "safety margin," rendering models more vulnerable to black-box attacks and proving that inference-time utility improvements must be rigorously audited for unintended safety externalities.
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All authors Chen Xiong, Zhiyuan He, Pin-Yu Chen, Ching-Yun Ko, Tsung-Yi Ho
Cryptography and Security
Privacy Amplification Persists under Unlimited Synthetic Data Release
Clément Pierquin, Aurélien Bellet, Marc Tommasi et al. (+1 more)
We study
privacy amplification by synthetic data release, a phenomenon in which differential
privacy guarantees are improved by releasing only synthetic data rather than the private generative model itself. Recent work by Pierquin et al. (2025) established the first formal amplification guarantees for a linear generator, but they apply only in asymptotic regimes where the model dimension far exceeds the number of released synthetic records, limiting their practical relevance. In this work, we show a surprising result: under a bounded-parameter assumption,
privacy amplification persists even when releasing an unbounded number of synthetic records, thereby improving upon the bounds of Pierquin et al. (2025). Our analysis provides structural insights that may guide the development of tighter
privacy guarantees for more complex release mechanisms.
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All authors Clément Pierquin, Aurélien Bellet, Marc Tommasi, Matthieu Boussard
Cryptography and Security
Evaluating the Vulnerability Landscape of LLM-Generated Smart Contracts
Hoang Long Do, Nasrin Sohrabi and Muneeb Ul Hassan
Large
language models (LLMs) have been widely adopted in modern software development lifecycles, where they are increasingly used to automate and assist code generation, significantly improving developer productivity and reducing development time. In the blockchain domain, developers increasingly rely on LLMs to generate and maintain smart contracts, the immutable, self-executing components of decentralized applications. Because deployed smart contracts cannot be modified, correctness and security are paramount, particularly in high-stakes domains such as finance and governance. Despite this growing reliance, the security implications of LLM-generated smart contracts remain insufficiently understood. In this work, we conduct a systematic security analysis of Solidity smart contracts generated by state-of-the-art LLMs, including ChatGPT, Gemini, and Sonnet. We evaluate these contracts against a broad set of known smart contract vulnerabilities to assess their suitability for direct deployment in production environments. Our extensive experimental study shows that, despite their syntactic correctness and functional completeness, LLM-generated smart contracts frequently exhibit severe security flaws that could be exploited in real-world settings. We further analyze and categorize these vulnerabilities, identifying recurring weakness patterns across different models. Finally, we discuss practical countermeasures and development guidelines to help mitigate these risks, offering actionable insights for both developers and researchers. Our findings aim to support safe integration of LLMs into smart contract development workflows and to strengthen the overall security of the blockchain ecosystem against future security failures.
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Cryptography and Security · Cross-listed from cs.LG
A Consensus-Bayesian Framework for Detecting Malicious Activity in Enterprise Directory Access Graphs
Pratyush Uppuluri, Shilpa Noushad and Sajan Kumar
This work presents a consensus-based
Bayesian framework to detect malicious user behavior in enterprise directory access graphs. By modeling directories as topics and users as
agents within a multi-level interaction graph, we simulate access
evolution using influence-weighted opinion dynamics. Logical dependencies between users are encoded in dynamic
matrices Ci, and directory similarity is captured via a shared influence
matrix W. Malicious behavior is injected as cross-component logical perturbations that violate structural norms of strongly connected components(SCCs). We apply theoretical guarantees from opinion dynamics literature to determine topic convergence and detect anomaly via scaled opinion variance. To quantify uncertainty, we introduce a
Bayesian anomaly scoring mechanism that evolves over time, using both static and online priors. Simulations over synthetic access graphs validate our method, demonstrating its sensitivity to logical inconsistencies and robustness under dynamic perturbation.
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Cryptography and Security
Boost+: Equitable, Incentive-Compatible Block Building
Mengqian Zhang, Sen Yang, Kartik Nayak et al. (+1 more)
Block space on the blockchain is scarce and must be allocated efficiently through block building. However, Ethereum's current block-building ecosystem, MEV-Boost, has become highly centralized due to integration, which distorts competition, reduces blockspace efficiency, and obscures MEV flow transparency. To guarantee equitability and economic efficiency in block building, we propose $\mathrm{Boost+}$, a system that decouples the process into collecting and ordering transactions, and ensures equal access to all collected transactions. The core of $\mathrm{Boost+}$ is the mechanism $\mathit{M}_{\mathrm{Boost+}}$, built around a default
algorithm. $\mathit{M}_{\mathrm{Boost+}}$ aligns incentives for both searchers (intermediaries that generate or route transactions) and builders: Truthful bidding is a dominant strategy for all builders. For searchers, truthful reporting is dominant whenever the default
algorithm dominates competing builders, and it remains dominant for all conflict-free transactions, even when builders may win. We further show that even if a searcher can technically integrate with a builder, non-integration combined with truthful bidding still dominates any deviation for conflict-free transactions. We also implement a concrete default
algorithm informed by empirical analysis of real-world transactions and evaluate its efficacy using historical transaction data.
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All authors Mengqian Zhang, Sen Yang, Kartik Nayak, Fan Zhang
Cryptography and Security · Cross-listed from stat.ML
Privacy utility trade offs for parameter estimation in degree heterogeneous higher order networks
Bibhabasu Mandal and Sagnik Nandy
In sensitive applications involving relational
datasets, protecting information about individual links from
adversarial queries is of paramount importance. In many such settings, the available data are summarized solely through the degrees of the nodes in the network. We adopt the $\beta$ model, which is the prototypical statistical model adopted for this form of aggregated relational information, and study the problem of minimax-optimal parameter estimation under both local and central differential
privacy constraints. We establish finite sample minimax lower bounds that characterize the precise dependence of the estimation risk on the network size and the
privacy parameters, and we propose simple
estimators that achieve these bounds up to constants and logarithmic factors under both local and central differential
privacy frameworks. Our results provide the first comprehensive finite sample characterization of
privacy utility trade offs for parameter estimation in $\beta$ models, addressing the classical graph case and extending the analysis to higher order hypergraph models. We further demonstrate the effectiveness of our methods through experiments on synthetic data and a real world communication network.
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Cryptography and Security
WebSentinel: Detecting and Localizing Prompt Injection Attacks for Web Agents
Xilong Wang, Yinuo Liu, Zhun Wang et al. (+2 more)
Prompt injection attacks manipulate webpage content to cause web
agents to execute attacker-specified tasks instead of the user's intended ones. Existing methods for detecting and localizing such attacks achieve limited effectiveness, as their underlying assumptions often do not hold in the web-
agent setting. In this work, we propose WebSentinel, a two-step approach for detecting and localizing
prompt injection attacks in webpages. Given a webpage, Step I extracts segments of interest that may be contaminated, and Step II evaluates each segment by checking its consistency with the webpage content as context. We show that WebSentinel is highly effective, substantially outperforming baseline methods across multiple
datasets of both contaminated and clean webpages that we collected. Our code is available at: https://github.com/wxl-lxw/WebSentinel.
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All authors Xilong Wang, Yinuo Liu, Zhun Wang, Dawn Song, Neil Gong
Cryptography and Security
mopri - An Analysis Framework for Unveiling Privacy Violations in Mobile Apps
Cornell Ziepel, Stephan Escher, Sebastian Rehms et al. (+1 more)
Everyday services of society increasingly rely on mobile applications, resulting in a conflicting situation between the possibility of participation on the one side and user
privacy and digital freedom on the other. In order to protect users' rights to informational self-determination, regulatory approaches for the collection and processing of personal data have been developed, such as the EU's GDPR. However, inspecting the compliance of mobile apps with
privacy regulations remains difficult. Thus, in order to enable end users and enforcement bodies to verify and enforce data protection compliance, we propose mopri, a conceptual framework designed for analyzing the behavior of mobile apps through a comprehensive, adaptable, and user-centered approach. Recognizing the gaps in existing frameworks, mopri serves as a foundation for integrating various analysis tools into a streamlined, modular pipeline that employs static and dynamic analysis methods. Building on this concept, a prototype has been developed which effectively extracts permissions and tracking libraries while employing robust methods for dynamic traffic recording and decryption. Additionally, it incorporates result enrichment and reporting features that enhance the clarity and usability of the analysis outcomes. The prototype showcases the feasibility of a holistic and modular approach to
privacy analysis, emphasizing the importance of continuous adaptation to the evolving challenges presented by the mobile app ecosystem.
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All authors Cornell Ziepel, Stephan Escher, Sebastian Rehms, Stefan Köpsell
Cryptography and Security
Reference-Free EM Validation Flow for Detecting Triggered Hardware Trojans
Mahsa Tahghigh and Hassan Salmani
Hardware Trojans (HTs) threaten the trust and reliability of integrated
circuits (ICs), particularly when triggered HTs remain dormant during standard testing and activate only under rare conditions. Existing electromagnetic (EM) side-channel-based detection techniques often rely on golden references or labeled data, which are infeasible in modern distributed manufacturing. This paper introduces a reference-free, design-agnostic framework for detecting triggered HTs directly from post-silicon EM emissions. The proposed flow converts each EM trace into a time-frequency scalogram using Continuous Wavelet Transform (CWT), extracts discriminative features through a convolutional neural network (CNN), reduces dimensionality with principal component analysis (PCA), and applies
Bayesian Gaussian Mixture Modeling (BGMM) for unsupervised probabilistic clustering. The framework quantifies detection confidence using posterior-based metrics (alpha_{post}, beta_{post}),
Bayesian information criterion (Delta BIC), and Mahalanobis cluster separation (D), enabling interpretable anomaly decisions without golden data. Experimental validation on AES-128 designs embedded with four different HTs demonstrates high separability between HT-free and HT-activated conditions and robustness to PCA variance thresholds. The results highlight the method's scalability, statistical interpretability, and potential for extension to runtime and in-field HT monitoring in trusted microelectronics.
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Cryptography and Security
Can Developers rely on LLMs for Secure IaC Development?
Ehsan Firouzi, Shardul Bhatt and Mohammad Ghafari
We investigated the capabilities of GPT-4o and Gemini 2.0 Flash for secure Infrastructure as Code (IaC) development. For security smell detection, on the Stack Overflow
dataset, which primarily contains small, simplified code snippets, the models detected at least 71% of security smells when prompted to analyze code from a security perspective (general
prompt). With a guided
prompt (adding clear, step-by-step instructions), this increased to 78%.In GitHub repositories, which contain complete, real-world project scripts, a general
prompt was less effective, leaving more than half of the smells undetected. However, with the guided
prompt, the models uncovered at least 67% of the smells. For secure code generation, we prompted LLMs with 89 vulnerable synthetic scenarios and observed that only 7% of the generated scripts were secure. Adding an explicit instruction to generate secure code increased GPT secure output rate to 17%, while Gemini changed little (8%). These results highlight the need for further research to improve LLMs' capabilities in assisting developers with secure IaC development.
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Cryptography and Security
Don't believe everything you read: Understanding and Measuring MCP Behavior under Misleading Tool Descriptions
Zhihao Li, Boyang Ma, Xuelong Dai et al. (+4 more)
The Model Context Protocol (MCP) enables large
language models to invoke external tools through natural-
language descriptions, forming the foundation of many AI
agent applications. However, MCP does not enforce consistency between documented tool behavior and actual code execution, even though MCP Servers often run with broad system privileges. This gap introduces a largely unexplored security risk. We study how mismatches between externally presented tool descriptions and underlying implementations systematically shape the mental models and decision-making behavior of intelligent
agents. Specifically, we present the first large-scale study of description-code inconsistency in the MCP ecosystem. We design an automated static analysis framework and apply it to 10,240 real-world MCP Servers across 36 categories. Our results show that while most servers are highly consistent, approximately 13% exhibit substantial mismatches that can enable undocumented privileged operations, hidden state mutations, or unauthorized financial actions. We further observe systematic differences across application categories, popularity levels, and MCP marketplaces. Our findings demonstrate that description-code inconsistency is a concrete and prevalent attack surface in MCP-based AI
agents, and motivate the need for systematic
auditing and stronger transparency guarantees in future
agent ecosystems.
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All authors Zhihao Li, Boyang Ma, Xuelong Dai, Minghui Xu, Yue Zhang, Biwei Yan, Kun Li
Cryptography and Security · Cross-listed from cs.IT
Secure Decentralized Pliable Index Coding for Target Data Size
Anjali Padmanabhan, Danya Arun Bindhu, Nujoom Sageer Karat et al. (+1 more)
Decentralized Pliable Index Coding (DPIC) problem addresses efficient information exchange in distributed systems where clients communicate among themselves without a central server. An important consideration in DPIC is the heterogeneity of side-information and demand sizes. Although many prior works assume homogeneous settings with identical side-information cardinality and single message demands, these assumptions limit real-world applicability where clients typically possess unequal amounts of prior information. In this paper, we study DPIC problem under heterogeneous side-information cardinalities. We propose a transmission scheme that coordinates client broadcasts to maximize coding efficiency while ensuring that each client achieves a common target level $T$. In addition, we impose a strict security constraint that no client acquires more than the target $T$ number of messages, guaranteeing that each client ends up with exactly $T$ messages. We analyze the communication cost incurred by the proposed scheme under this security constraint.
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All authors Anjali Padmanabhan, Danya Arun Bindhu, Nujoom Sageer Karat, Shanuja Sasi
Cryptography and Security
Detecting and Explaining Malware Family Evolution Using Rule-Based Drift Analysis
Olha Jurečková and Martin Jureček
Malware detection and classification into families are critical tasks in cybersecurity, complicated by the continual
evolution of malware to evade detection. This
evolution introduces concept drift, in which the statistical properties of malware features change over time, reducing the effectiveness of static machine learning models. Understanding and explaining this drift is essential for maintaining robust and trustworthy malware detectors. In this paper, we propose an interpretable approach to concept drift detection. Our method uses a rule-based classifier to generate human-readable descriptions of both original and evolved malware samples belonging to the same malware family. By comparing the resulting rule sets using a similarity function, we can detect and quantify concept drift. Crucially, this comparison also identifies the specific features and feature values that have changed, providing clear explanations of how malware has evolved to bypass detection. Experimental results demonstrate that the proposed method not only accurately detects drift but also provides actionable insights into the behavior of evolving malware families, supporting both detection and threat analysis.
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Cryptography and Security
Reading Between the Code Lines: On the Use of Self-Admitted Technical Debt for Security Analysis
Nicolás E. Díaz Ferreyra, Moritz Mock, Max Kretschmann et al. (+4 more)
Static Analysis Tools (SATs) are central to security engineering activities, as they enable early identification of code weaknesses without requiring execution. However, their effectiveness is often limited by high false-positive rates and incomplete coverage of vulnerability classes. At the same time, developers frequently document security-related shortcuts and compromises as Self-Admitted Technical Debt (SATD) in software artifacts, such as code comments. While prior work has recognized SATD as a rich source of security information, it remains unclear whether -and in what ways- it is utilized during SAT-aided security analysis. OBJECTIVE: This work explores whether and how the security-related information encoded in SATD provides complementary security insights to SATs. METHOD: We followed a mixed-methods approach comprising (i) the analysis of a manually curated, SATD-annotated vulnerability
dataset using three SATs and (ii) an online survey involving 72 security-aware software practitioners. RESULTS: The selected SATs flagged 114 of the 135 validated Security-related SATD instances (SSATD), yet the overlap between SAT-derived and manually mapped Common Weakness Enumeration (CWE) identifiers was only 6.42%, indicating that both sources often expose different kinds of security information. In particular, SSATD captured several dynamic and context-dependent weakness types that SATs commonly overlook or struggle to detect. Survey responses further indicate that practitioners rely on SSATD to contextualize SAT findings by understanding their impact, root causes, and potential fixes. IMPLICATIONS: Our findings suggest that SSATD constitutes a valuable and cost-effective source of complementary security knowledge that can support the interpretation, prioritization, and further assessment of SAT findings.
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All authors Nicolás E. Díaz Ferreyra, Moritz Mock, Max Kretschmann, Barbara Russo, Mojtaba Shahin, Mansooreh Zahedi, Riccardo Scandariato
Cryptography and Security
Origin Lens: A Privacy-First Mobile Framework for Cryptographic Image Provenance and AI Detection
Alexander Loth, Dominique Conceicao Rosario, Peter Ebinger et al. (+2 more)
The proliferation of generative AI poses challenges for information integrity assurance, requiring systems that connect model governance with end-user verification. We present Origin Lens, a
privacy-first mobile framework that targets visual disinformation through a layered verification architecture. Unlike server-side detection systems, Origin Lens performs cryptographic image provenance verification and AI detection locally on the device via a Rust/Flutter hybrid architecture. Our system integrates multiple signals - including cryptographic provenance, generative model fingerprints, and optional
retrieval-augmented verification - to provide users with graded confidence indicators at the point of consumption. We discuss the framework's
alignment with regulatory requirements (EU AI Act, DSA) and its role in verification infrastructure that complements platform-level mechanisms.
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All authors Alexander Loth, Dominique Conceicao Rosario, Peter Ebinger, Martin Kappes, Marc-Oliver Pahl