Cryptography and Security
zQR: A Verifiable QR-Driven zkSNARK Proof Verification Framework for Mobile Platforms
Goshgar Can Ismayilov
Privacy is one of the fundamental rights of individuals in modern societies. Yet, the practical adoption of
privacy-preserving technologies in daily interactions remains limited. Zero-knowledge proofs offer strong
privacy guarantees but are often hindered by their technical complexity. In this paper, we advance the idea of verifiable QR codes that enable off-line verifiers to verify proofs encoded in QR codes. Based on this core idea, we build a novel QR-driven zkSNARK proof verification framework (i.e., zQR) for mobile platforms. The framework integrates blockchain for auditability, non-repudiation and logging; and large-
language models for automatic
circuit generation. We perform a security discussion of the framework by considering multiple attack surfaces. Furthermore, we present an experimental evaluation measuring temporal costs (proof generation and verification latency, QR code encoding and decoding latency) and financial costs (blockchain gas consumption). Our results demonstrate the feasibility of zQR as a proof-of-concept framework for
privacy-preserving verification on mobile platform where proofs are compactly represented with QR code symbol version of 19 with low error correction level. Finally, we discuss potential applications, current limitations and future directions for the broader adoption of
privacy-preserving technologies in daily interactions.
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Cryptography and Security
Inherited Circuits, Learned Semantics: How Fine-Tuning Creates Evasion Vulnerabilities Invisible to Standard Evaluation
Ryan Fetterman
LLMs fine-tuned for security classification are usually evaluated on held-out examples from the same distribution as their training data. We show that this can miss vulnerabilities introduced by fine-tuning itself: models can learn
token-level indicator semantics that preserve canonical accuracy while failing under behavior-preserving transformations such as PowerShell alias substitution, command reconstruction, string construction, execution indirection, and case mutation. We study Foundation-Sec-8B-Instruct and its base model, Llama-3.1-8B-Instruct, on matched PowerShell classification cohorts. Causal interventions localize the classification
circuit to a late-
attention route inherited from Llama rather than created by fine-tuning. Fine-tuning concentrates and semantically specializes this inherited structure, improving baseline behavior while creating transformation-sensitive attack surfaces. A three-tier evasion
benchmark finds Foundation-Sec misses on iwr substitution, Invoke-Expression reconstruction, and case-mutated Invoke-Expression/IEX variants that Llama does not share. We also derive a pre-deployment monitoring method: a linear probe at the classification boundary and an indicator-
token sign test identify command families where canonical indicators change role after fine-tuning. These signals prioritize red-team variant generation using only canonical inputs, showing that security fine-tuning can improve task accuracy while expanding the evasion surface. These results caution against treating small task-specific fine-tunes as straightforwardly safer security classifiers: specialization can convert inherited model structure into brittle indicator rules that preserve held-out accuracy while expanding the evasion surface. Robust AI-enabled security will require specifying the full transformation space of the task and monitoring semantic drift through fine-tuning.
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Cryptography and Security
Type-based information flow analysis for $\pi$-calculus with a dynamically extensible security lattice
Yukihiro Oda and Eijiro Sumii
We develop a type system for secure information flow where new security levels can be created and inserted into the security
lattice dynamically, i.e., even in the middle of an execution of a system. Our system is formalized by extending Kobayashi's type-based secure information flow analysis for Milner's pi-calculus, which is one of the most expressive models (or "
languages") supporting both sequential and concurrent computations, with concise syntax, reduction-based semantics, and bisimulation equivalence as a robust formalization of secrecy as non-interference. The development required careful treatment of extensions of
lattices themselves as well as deliberate generalization from the simple 2-element
lattice (consisting of only High and Low) in the original system.
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Cryptography and Security
Physical Layer Authentication With Channel Knowledge Maps in Indoor Environments
Luca Bonaventura, Francesco Ardizzon and Stefano Tomasin
Physical layer authentication (PLA) allows to authenticate the user by comparing measurements over time, assuming their time consistency or by modeling their
evolution. However, these assumptions become problematic when devices are in motion and in indoor environments due to multipath propagation and obstructions. In this paper, we propose a PLA mechanism for moving devices in indoor environments, where multiple access points (APs) estimate the dominant channel tap path loss (PL) and angle of arrival (AoA) from the received signals and compare them with previously collected channel knowledge maps (CKMs). Specifically, the measurements are compared to those in the neighborhood of the previously known position obtained from CKMs. A comprehensive security analysis is conducted under both random and optimal attacks. Numerical results in a representative indoor scenario, with CKM obtained via ray tracing, validate the effectiveness of the proposed PLA approach.
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Cryptography and Security
Design and Performance Evaluation of Secure RF and WiFi-Based Communication in Drone Swarms via Testbed Implementation
Bhavya Dixit, Aayushi Rajgor, Subham Kumar et al. (+4 more)
Unmanned aerial vehicle (
UAV) swarms rely on distributed coordination and cooperative communication to support scalable operations, extended coverage, and applications such as surveillance and real-time data exchange. Wireless technologies such as
radio frequency (RF) and WiFi are widely used for
UAV-to-
UAV and
UAV-to-ground control station (GCS) communication but introduce significant security challenges. MAVLink, the predominant communication protocol in
UAV systems, provides message integrity and authentication but lacks built-in encryption, leaving telemetry traffic vulnerable to eavesdropping. In our previous work, we proposed MAVShield, a lightweight encryption framework for MAVLink communications. In this paper, MAVShield, AES-CTR, Speck-CTR, ChaCha20, and Rabbit are integrated into four custom-built
UAVs to establish secure communication links over RF and WiFi channels. Their performance is evaluated through flight experiments using a
UAV swarm testbed. Encrypted telemetry data enable autonomous formation control and collision avoidance during flight. For collision avoidance, we develop a modified artificial potential field (APF)
algorithm that computes attractive and repulsive forces directly in geodetic coordinates, eliminating Cartesian transformations and reducing trajectory oscillations while avoiding local-minimum trapping. CPU utilization,
memory consumption, and packet delivery ratio (PDR) are measured for each encryption scheme. Results show that MAVShield achieves performance comparable to unencrypted communication while outperforming AES-CTR, Speck-CTR, ChaCha20, and Rabbit in overall efficiency. Algebraic cryptanalysis and Wireshark-based traffic analysis demonstrate resistance to key-recovery attacks and protection of telemetry confidentiality. The results indicate that MAVShield is an efficient and secure solution for
UAV swarm communication.
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All authors Bhavya Dixit, Aayushi Rajgor, Subham Kumar, Rushikesh Patil, Ananthapadmanabhan A., Gaurav S. Kasbekar, Arnab Maity
Cryptography and Security
ShareLock: A Stealthy Multi-Tool Threshold Poisoning Attack Against MCP
Liwei Liu, Tianzhu Han, Zijian Liu et al. (+2 more)
With the rapid
evolution of LLM-driven
agents, Model Context Protocol (MCP), an open protocol bridging LLMs with external tools, has quickly become foundational to modern
agent ecosystems. However, the expanding adoption of MCP has also introduced novel security concerns such as Tool Poisoning Attack (TPA), which exploit LLM-server interactions to inject malicious
prompts. Existing poisoning schemes typically adopt a monolithic plaintext
embedding paradigm, which fails to withstand manual inspection or automated detectors. Current research still lacks a systematic analysis on multi-tool poisoning, where multiple tools can be exploited cooperatively to disperse detection risk. In this paper, we introduce ShareLock, a multi-tool threshold poisoning framework that utilizes Shamir's threshold scheme to ensure exceptional stealth and fault tolerance. ShareLock distributes the malicious instruction as benign-looking secret shares across multiple tool descriptions, achieving both information-theoretic secrecy and attack robustness against moderate
auditing. After a covert reconstruction trigger is planted during server update, the aggregated shares reconstruct the hidden instruction, resulting in critical breaches of system assets or private data. To evaluate the realistic threat of ShareLock, we constructed a comprehensive
benchmark encompassing four multi-tool scenarios and conducted extensive experiments across mainstream LLMs on two distinct MCP clients. Our results demonstrate that ShareLock significantly outperforms existing single-tool poisoning strategies in tool description-based detection while maintaining an average attack success rate exceeding 90%.
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All authors Liwei Liu, Tianzhu Han, Zijian Liu, Zishu Dong, Na Ruan
Cryptography and Security
Protocol Prying: Systematic Vulnerability Research in the Apple AirDrop and Android Quick Share Proximity Transfer Protocols
Arash Ale Ebrahim and Nils Ole Tippenhauer
Apple AirDrop and Google/Samsung Quick Share are proximity file-transfer protocols used by over five billion devices, yet their application-layer security properties remain largely unstudied because both stacks are proprietary and undocumented. Both protocols are reachable from wireless proximity without any prior pairing and process complex serialized content (binary plists, CPIO archives, Protocol Buffers, UKEY2 handshakes) inside privileged daemons, making them attractive zero-click targets across multiple operating systems. We perform the first cross-platform reverse engineering and protocol-aware fuzzing study of both stacks. We reconstruct AirDrop's seven-layer state machine and DVZip adaptive compression from binary analysis, build AIRFUZZ, a protocol-aware fuzzer that mutates pre-compression representations, and complement it with targeted hand-written analyses of Samsung's Quick Share service and Google's Quick Share for Windows. We discover six vulnerabilities (V1-V6): three pre-authentication issues in macOS/iOS AirDrop (V1: Swift fatalError DoS in the HTTP path router; V2: unbounded XML plist recursion in Foundation; V3: NULL dereference in Network.framework's HTTP/1.1 parser), two protocol-layer flaws in Samsung Quick Share (V4: pre-authentication OfflineFrame dispatch; V5: D2D encryption bypass for three frame types), and a heap use-after-free in Google Quick Share for Windows (V6) for which Google awarded a bounty. We responsibly disclosed all findings, and Apple, Samsung, and Google have acknowledged the reports.
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Cryptography and Security
Jailbreaking for the Average Jane: Choosing Optimal Jailbreaks via Bandit Algorithms for Automatically Enhanced Queries
Prarabdh Shukla, Ritik, Suhas Rao et al. (+2 more)
With a profusion of jailbreaks for LLMs now widely known, a growing concern is that non-expert malicious actors ("the average Jane") could elicit actionable responses to malicious requests. In this work, we examine whether this concern is justified. A non-expert malicious actor requires two ingredients for a successful attack: a powerful jailbreak for their target model, acting on an effective malicious query. For the former, we propose a novel attack strategy based on the multi-armed bandit framework. This allows efficient online learning of the optimal jailbreak from a large choice set via noisy exploration on a small number of queries, with subsequent application of the learnt policy on an exploitation set. For the latter, we curate $\mathrm{FrankensteinBench}$, a safety
benchmark of $11,279$ malicious queries drawn from manual curation over $7$ existing
benchmarks, along with automated enhancement and generation. Each query is categorized as simple or complex by the technical expertise required to craft it. Our findings confirm the concern. Our bandit-based attack achieves success rates as high as $97\%$ on average over $15$ SoTA open-weight LLMs. Moreover, adding complexity to queries raises the attack success rate by up to $26\%$ on average across models – making it an effective, automatable prompting strategy.
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All authors Prarabdh Shukla, Ritik, Suhas Rao, Arpit Agarwal, Arjun Bhagoji
Cryptography and Security
Chai: Agentic Discovery of Cryptographic Misuse Vulnerabilities
Corban Villa, Sohee Kim, Austin Chu et al. (+2 more)
AI-assisted vulnerability discovery has proven effective for bug classes like
memory safety, where instrumentation confirms
memory violations and efficiently filters false positives. Many dangerous vulnerability classes, such as cryptographic misuse, however, lack any comparable instrumentation. In this work, we present Chai, an AI-based system that discovers and validates cryptographic misuse vulnerabilities through naturally occurring signals. To achieve this, Chai rethinks the classical technique of differential testing by leveraging AI to 1) improve precision for detecting real security issues in libraries, and 2) repurpose commonly overlooked discrepancies as leads for tangible vulnerabilities in downstream applications. In doing so, Chai inverts the prevailing paradigm of AI vulnerability discovery: instead of
auditing one codebase for many flaws, it catalogs flaws at the library level and propagates them across a cryptographic dependency graph, delivering compounding efficiency gains. We evaluate Chai across X.509, JWT, and SAML libraries. Chai discovered a previously unknown critical vulnerability in an SSL library that powers billions of devices, along with security bugs in one library behind a major web browser and another in major Linux distributions. In total, these techniques surfaced over 100 vulnerabilities.
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All authors Corban Villa, Sohee Kim, Austin Chu, Alon Shakevsky, Raluca Ada Popa
Cryptography and Security · Cross-listed from cs.SE
A Deterministic Control Plane for LLM Coding Agents
Padmaraj Madatha
LLM coding harnesses grant
agents broad file and shell access, yet the configuration layer that steers them – rules files,
agent definitions, IDE-specific markdown – is largely unmanaged. A prevalence study of 10,008 public GitHub repositories (n=6,145
agent config files) finds that
agent configurations propagate as undeclared shared components: 10.1% of tracked paths are SHA-256 exact duplicates across independent repositories (fork-adjusted, threshold-independent), with 75.5% of clone pairs crossing organisational boundaries. Two further patterns are indicative: configurations are rarely revised (58% single-commit; 0.4 vs 0.6 commits/month age-normalised against CI/CD workflows), and rarely declare permission boundaries (<1% of
agent configs vs 33% of Actions workflows, n=31 true positives). We propose a deterministic control plane above the harness that maps one-to-one to these gaps. Rel(AI)Build treats
agent definitions as a managed supply chain (SHA-256 content addressing, HMAC-stamped lockfiles, hash-chained audit logs); enforces tiered permissions and attack-derived blocklists before LLM invocation; gates feature work through a phase state machine with requirement-to-file-to-test traceability; compiles a single canonical definition to seven IDE targets; and detects
prompt drift via Jaccard similarity. Conformance tests on injected violations confirm each mechanism enforces its stated invariant; developer outcomes remain future work. Governance of this layer must be deterministic and tool-agnostic – not delegated to further LLM orchestration.
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Cryptography and Security
Fortress and Gatekeeper: Theorizing Transitive Trust in Third-Party Cybersecurity Risk Governance
Yijun Chen and Misita Anwar
Third-party vendors, such as analytics platforms, cloud services, identity providers, and software suppliers, are increasingly embedded in digital service delivery. While these arrangements enable scale and specialization, they also move customer data and security-relevant practices into environments that customers rarely see, select, or evaluate. This paper examines this problem through a document analysis of the November 2025 OpenAI-Mixpanel security incident. The incident serves as an illustrative case for showing how a security event in a vendor environment can become a governance and accountability problem for the focal organization that maintains the customer relationship. Drawing on organizational trust research and agency theory, the paper argues that third-party cybersecurity risk is both a trust relationship and a delegation problem. Customers trust the visible service provider, while the provider relies on vendors whose security practices are only partially visible and controllable. The paper develops the concept of transitive trust, where customer trust in a digital service depends on the security practices of vendors authorized by that service provider. It then presents the Fortress and Gatekeeper framework, which explains cybersecurity governance boundaries through trust and data flows rather than formal organizational ownership alone. The analysis develops four propositions concerning vendor integration, metadata exposure, vendor assurance, and data proliferation. The paper contributes to cybersecurity governance scholarship by explaining how delegated data processing creates customer-facing accountability and by identifying implications for vendor tiering, data classification, contractual design, continuous assurance, and data minimization.
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Cryptography and Security
SpikeTimer: Exploring Active Copyright Protection in Spiking Neural Networks via Temporal Backdoor Regularization
Xiao Yang, Gaolei Li, Jun Wu et al. (+2 more)
Spiking Neural Networks (SNN) have emerged as a revolutionary paradigm compared to traditional Deep Neural Networks (DNN) in energy-efficient computing, showcasing exceptional capabilities in processing event-driven sensory data for real-time applications like robotics and edge AI systems. However, unlike extensive studies on DNN copyright solutions, SNN copyright protection remains largely underexplored due to their inherent temporal coding complexities and spike-driven computation. In this study, we propose a novel active copyright protection framework named SpikeTimer for SNNs via temporal
backdoor learning. SpikeTimer partitions neuromorphic data into designated timeslices and exclusively embeds authorized
tokens within authorized slices. Furthermore, the inherent temporal
segmentation characteristic intrinsically enables SpikeTimer to support multi-user authorization mechanisms and accommodates
token embedding of arbitrary morphology. Based on this, SpikeTimer precisely responds to authorized data containing a
token within the correct timeslice, while producing erroneous responses to unauthorized data. Our key innovation lies in establishing a time-dependent authorization mechanism that protects the SNN copyright by temporal
token validity. Additionally, SpikeTimer retains its defensive efficacy even under
adversarial attempts. Evaluations on multiple neuromorphic
datasets manifest that SpikeTimer achieves around 10% accuracy on unauthorized data with merely around 1.5% degradation on authorized inputs. Moreover, SpikeTimer demonstrates robust resistance against model finetuning and
pruning threats.
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All authors Xiao Yang, Gaolei Li, Jun Wu, Jianhua Li, Zhiquan Liu
Cryptography and Security
MIRROR: Novelty-Constrained Memory-Guided MCTS Red-Teaming for Agentic RAG
Inderjeet Singh, Andrés Murillo, Motoyoshi Sekiya et al. (+2 more)
Multimodal agentic
retrieval-augmented generation (RAG) systems expand the attack surface beyond
prompt injection to include text poisoning, image injection, direct-query attacks, and orchestrator-level tool manipulation. Existing red-teaming approaches are typically surface-specific and often recycle known attack templates; on text-poisoning
benchmarks we measure 73-84% exact duplication. We present MIRROR, a unified cross-surface framework that performs
memory-guided Monte Carlo tree search while conditioning candidate generation on retrieved context under an explicit novelty constraint. A deterministic Novelty Gate rejects any candidate matching the
retrieval set under normalized comparison, allowing
retrieval to inform search priors without enabling
prompt copying. Across four attack surfaces on a
multimodal agentic RAG target, MIRROR attains 76% ASR on image poisoning compared with 52% for baselines, 97% ASR on orchestrator attacks at half the query cost, and the lowest cross-surface variance (coefficient of variation 0.47). In contrast, specialized baselines collapse across surfaces: suffix optimization reaches 79% ASR on text poisoning but 1% on direct queries. We release ART-SafeBench with 41,815 in-package records and runtime adapters yielding 41,991+ total records across four surfaces.
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All authors Inderjeet Singh, Andrés Murillo, Motoyoshi Sekiya, Yuki Unno, Junichi Suga
Cryptography and Security
MergeLLL: A Hierarchical Divide-and-Conquer Framework for LLL-Based Lattice Reduction
Niharika Gauraha
Lattice basis reduction
algorithms have various applications in computational number theory and
lattice-based cryptography, but their complexity increases rapidly with the dimension. Motivated by the divide-and-conquer strategy of merge sort and incorporating PotLLL-style deep insertions during recombination, MergeLLL is proposed. In this framework, a
lattice basis is split into sub-bases (blocks), where local reductions are performed within each block using KZ reduction, approximated in practice by BKZ with block size equal to the sublattice dimension. The full basis is then reconstructed through a hierarchical merging process. The approach focuses on improving local
lattice structure before refining global basis properties. The method is naturally parallelizable, enabling efficient multicore and distributed execution. The reduction and merging steps preserve the
lattice structure via unimodular transformations and admit logarithmic parallel depth. In experiments on subset-sum and NTRU-style
lattices, the method is evaluated against PotLLL and BKZ 2.0, showing comparable computation time with PotLLL while achieving a lower root Hermite factor, indicating higher-quality reduced bases.
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Cryptography and Security
DroidBreaker: Practical and Functional Problem-Space Attacks on Machine-Learning Android Malware Detectors
Christian Scano, Diego Soi, Angelo Sotgiu et al. (+5 more)
Adversarial APKs are Android applications modified in the problem space to evade machine-learning malware detectors. In this work, we first show that, despite claims, existing problem-space attacks remain largely impractical. Most techniques leverage software transplantation to inject entire benign modules, introducing many side-effect features and often causing build-time failures. Fine-grained methods that inject only a narrow subset of components exhibit limited effectiveness, while those that also use obfuscation rely on brittle bytecode rewriting, producing APKs that are syntactically valid but semantically unusable. Prior work further overestimates attack success rates by running smoke tests that only validate installation and basic execution, without assessing whether the modified APK still preserves its intended behavior. To overcome these limitations, we present DROIDBREAKER, a practical (build-safe) and functional (semantics-preserving) problem-space attack framework that provides: (i) query-efficient white- and black-box attacks by manipulating only the APK components most influential to the target model; (ii) a set of fine-grained, build-safe manipulations (including injection and obfuscation of API calls, app modules, permissions, and URLs) with minimal side effects; and (iii) a semantics-preserving functionality test that enforces runtime equivalence by comparing execution logs and API-level traces between the initial and the modified APK. Evaluated on a recent corpus of Android applications, DROIDBREAKER achieves high evasion rates with few queries and minimal side effects in both white-box and black-box settings, and drastically reduces detections by commercial malware scanners hosted on VirusTotal.
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All authors Christian Scano, Diego Soi, Angelo Sotgiu, Luca Demetrio, Davide Maiorca, Giorgio Giacinto, Fabio Roli, Battista Biggio
Cryptography and Security
The Fungible Reserve Standard: A Deterministic Framework for Encoding Carrying Costs in Asset-Backed Tokens
JJ Jia Jing Tan, Eva Meng, Josh Ng et al. (+5 more)
The tokenization of real-world assets (RWAs) has emerged as a transformative application of blockchain technology, with
market projections estimating trillions of dollars in tokenized assets within the coming decade. However, a fundamental challenge remains unaddressed: physical assets such as precious metals, stored commodities, and warehoused goods incur structural negative carry – custody, insurance, and audit costs that accumulate over time. While existing tokenization models have successfully established the
market for digital gold and treasuries, they typically manage operational costs at the issuer level. The FRS introduces a framework to bring these economics directly on-chain, avoiding mechanisms such as
token rebasing that compromise fungibility and composability with decentralized finance (DeFi) protocols. This paper proposes the Fungible Reserve Standard (FRS), a deterministic
token design framework that encodes carrying costs transparently into on-chain logic. The FRS introduces an asset-per-
token variable q(t) that decreases according to a predefined annualized carrying cost rate, coupled with a supply reconciliation mechanism that preserves holder balances and ERC-20 composability. While mathematically inspired by the daily expense ratio accrual in traditional asset management – which often embed centralized profit margins – the FRS design specifically encodes actual operational carrying costs to provide pure institutional-grade accounting clarity without compromising DeFi compatibility. The framework is asset-agnostic and applicable to any real-world asset with positive, predictable holding costs.
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All authors JJ Jia Jing Tan, Eva Meng, Josh Ng, Zack Zhang, September Liu, Teelet Wang, Ludwig Zhang, Seth Yan
Cryptography and Security
TGHE: Template-based Graph Homomorphic Encryption for Privacy-Preserving GNN Inference in Edge-Cloud Systems
Ngoc Bao Anh Le, Thai T. Vu, John Le et al. (+2 more)
Existing homomorphic encryption (HE)-based GNN systems adopt a graph-centric paradigm that couples per-query cost to global graph size, limiting evaluations to at most ~20k nodes and making them incompatible with dynamic, large-scale financial graphs. We propose TGHE (Template-based Graph Homomorphic Encryption), an ego-centric framework that resolves this by exploiting a template phenomenon: local computation trees in transaction graphs converge into a small set of structural shapes. TGHE canonicalizes ego-graphs at the edge and packs structurally identical trees into shared CKKS ciphertexts for SIMD-parallel encrypted inference, with two long-tail optimizers (Approximate Template Fitting and
Topology Collapse) ensuring full SIMD coverage. On DGraphFin (3.7M nodes, 4.3M edges), TGHE-Collapse achieves a 66.9x speedup over the sequential encrypted baseline with less than 0.002 AUC loss.
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All authors Ngoc Bao Anh Le, Thai T. Vu, John Le, Heath Cooper, Jun Shen
Cryptography and Security · Cross-listed from cs.AI
Autoformalization of Agent Instructions into Policy-as-Code
Adam Mondl, Matthew Maisel and John H. Brock
Agent safety in high-stakes domains requires formal policy enforcement, but most existing approaches either rely on probabilistic guardrails (fine-tuned classifiers,
prompt-based steering) that offer no formal guarantees, or on hand-coded symbolic enforcement that does not scale to the breadth of real policy specifications. We present an autoformalization pipeline that translates
agent prompts, MCP tool descriptions, and natural
language policy documents into formally verified policies using an LLM-based generator-critic loop. The resulting policies are written in the Cedar Policy
Language. On the MedAgentBench
benchmark, our autoformalized policies cover substantially more of the source natural-
language specification than the hand-coded symbolic enforcement in prior work.
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Cryptography and Security
Agents That Know Too Much: A Data-Centric Survey of Privacy in LLM Agents
Nada Lahjouji and Ashwin Gerard Colaco
Large
language model
agents increasingly query databases, search document collections, call external APIs, remember past interactions, and act on a user's behalf. As they move from answering questions to operating over sensitive data,
privacy becomes harder to enforce. An
agent touches many data sources, runs multi-step workflows, keeps state across sessions, and acts with delegated permissions. Sensitive information can therefore leak not only through its final answer but through the queries it issues, the intermediate results it handles, the
memory it writes, and the messages it exchanges with other
agents. We survey the
privacy of LLM
agents from a data-centric view, organizing the field around the data an
agent touches rather than by attack type, and we use data
agent as shorthand for an LLM
agent that works with data. Research on these risks is active but scattered across
retrieval-augmented generation, text-to-SQL interfaces,
agent memory,
prompt injection, access control, and contextual
privacy. This survey brings that work together: we taxonomize the data sources an
agent touches, the
privacy risks each source creates, and the governance mechanisms that address them; we map the
benchmarks used to measure these risks and identify what is missing; and we set out the open problems. Two findings recur: among governance mechanisms only information-flow control covers both compositional and cross-session inference leakage, the two least-protected risks; and no
benchmark drives an
agent across its data surfaces under one
privacy policy, the instrument the field most lacks. Our goal is a reference that situates the scattered literature and gives future work a common framing.
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Cryptography and Security · Cross-listed from cs.LG
Empirical Software Engineering TerraProbe: A Layered-Oracle Framework for Detecting Deceptive Fixes in LLM-Assisted Terraform
Manar Alsaid, Chimdumebi Nebolisa and Faris Abbas
Security misconfigurations in Terraform Infrastructure-as-Code are a growing risk in cloud deployments, and large
language models are increasingly used as automated repair
agents. Existing evaluations often treat a repair as successful when the targeted static-analysis finding disappears, without checking planning validity, behavioral change, or security intent. This paper presents TerraProbe, a five-layer oracle framework for evaluating LLM-assisted Terraform security repair. We apply TerraProbe to 288 first-pass repairs generated by gemini-2.5-flash-lite, GPT-4o, and Claude 3.5 Sonnet across 68 real-world TerraDS modules and 28 controlled injected-defect modules. The results show that targeted Checkov removal overstates repair success. Although targeted removal reaches 83.3 percent for the primary model, full-scanner cleanliness drops to 10.4 percent, Terraform planning succeeds for 39.6 percent, and plan comparison is reachable for 38.5 percent. Human adjudication further shows that 71.4 percent of plan-compared real-world repairs are deceptive fixes that pass automated checks while leaving the underlying vulnerability in place. This pattern is statistically indistinguishable across the three models, with deceptive-fix rates from 57.1 percent to 71.4 percent and pairwise Fisher exact p-values above 0.10. The paper introduces a four-dimensional taxonomy of deceptive fixes, validated with Cohen kappa of 0.78 and Krippendorff alpha of 0.76. IAM permission analysis confirms that wildcard Resource grants persist in all nine CKV2 AWS 11 deceptive-fix cases. TerraProbe contributes an evaluation methodology, a replication package, and the Multi-Layer Oracle Evaluation framework for distinguishing intent-aligned security repairs from scanner-passing false successes.
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Cryptography and Security
Adversarial Diffusion Across Modalities: A Fusion Survey of Attacks, Defenses, and Evaluation for Text, Vision, and Vision-Language Models
Abrar Alotaibi and Moataz Ahmed
Adversarial evaluation of AI systems has matured along four largely disconnected tracks:
diffusion-based attacks on text and large
language models (LLMs),
diffusion-based attacks on image classifiers, jailbreak pipelines against
vision-
language models, and
diffusion-based input purification defenses. Each has developed its own vocabulary, threat models, and
benchmarks, with denoising
diffusion models emerging as a shared generative mechanism whose recipes are now actively ported between communities. This survey performs an information-fusion exercise at the meta-research level: we integrate these four tracks into a single conceptual framework with a unified taxonomy, evaluation criteria, and research agenda, focusing on the LLM-side slice. We catalog fifty published papers across four scope areas (text/LLM, image classifier,
vision-
language model, defense), plus four
diffusion-LLM-as-victim entries and ten non-
diffusion baselines against which any new attack must be compared. We propose a six-class taxonomy of
diffusion roles in
adversarial pipelines, augmented by a threat-model axis recording attacker knowledge, query budget, and target accessibility, and apply a five-dimension framework (attack success rate, transferability, query budget, perplexity, defense-evasion) uniformly across modalities. The review adopts a dual attacker-defender perspective: alongside the attack catalog we cover four
diffusion-based defenses that form the natural evaluation backdrop for new attacks. Our critical analysis identifies five recurring weaknesses of the current LLM-side literature, and we close with a research agenda of open questions and concrete experimental designs. The companion catalog and spreadsheet are released with the paper. We are explicit that this is a narrative review with quality assessment, not a PRISMA-compliant systematic review, and discuss the implications for replication.
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Cryptography and Security
TESLA-for-5G: Broadcast Authentication for 5G Networks Using TESLA
Subin Song, Michael K. Reiter and Taekyoung Kwon
5G base stations broadcast unauthenticated system information (SI) that every user equipment (UE) reads during
cell selection. This enables attackers to broadcast forged SI from a fake base station (FBS), deceiving UEs into camping on it. Prior approaches to address this issue usually require UEs to authenticate System Information Block 1 (SIB1) using digital signatures. This necessitates computationally expensive verification for every SIB1 reception, imposing a significant burden on resource-constrained UEs. We propose TESLA-for-5G (TF5), a broadcast authentication protocol for 5G SIB1 that combines TESLA with GG09 Schnorr-like identity-based signatures (IBS). In the steady state, TF5 enables UEs to authenticate each SIB1 message using a symmetric MAC and delayed key disclosure, eliminating the need for per-message digital signatures. Initial trust is bootstrapped during
cell entry using a lightweight GG09 IBS over the TESLA parameters, avoiding certificate distribution overhead. We formally verify the security of TF5 in Tamarin under a Dolev -Yao adversary and demonstrate its favorable computation, communication, and storage costs through both an implementation on the OpenAirInterface 5G stack and trace-driven analysis.
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Cryptography and Security
VIGIL: Runtime Enforcement of Behavioral Specifications in AI Agent Skills
Ying Li, Yanju Chen, Hongbo Wen et al. (+5 more)
Agentic systems increasingly act through third-party skills, allowing model-generated decisions to affect files, communication channels, and cyber-physical devices. These skills often include natural-
language specifications that define access permissions, disclosure limits, execution privileges, and required preconditions. Although such specifications describe the intended boundaries of skill behavior, they do not by themselves provide executable runtime enforcement. Enforcing them raises a contextual granularity challenge: even when a policy is written for a particular task context, a monitor must still decide which events to observe, what state to retain, how far across the execution to reason, and where to intervene. Choosing the wrong granularity can either block benign executions or miss violations that emerge only across multiple actions. Most existing enforcement mechanisms, however, assume a fixed event model or enforcement point. In this work, we present VIGIL, an end-to-end runtime enforcement framework for agentic systems. VIGIL checks an
agent's actual execution trace against behavioral policies from skill specifications, operator-defined constraints, and global rules spanning multiple skills. To make such policies executable, VIGIL introduces a policy
language that captures context-specific enforcement requirements over
agent-tool events, including temporal dependencies, argument constraints, and value-flow conditions. The
language is paired with symbolic evaluation rules that translate policies into SMT constraints over finite traces, allowing VIGIL to detect violations that depend on event order, argument relationships, or cross-call value flow rather than relying on fixed single-call filters. On real LLM-
agent runs spanning office-document, operational, and engineering tasks, VIGIL detects policy violations with over 95% recall and a false-positive rate below 10%.
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All authors Ying Li, Yanju Chen, Hongbo Wen, Bosi Zhang, Hanzhi Liu, Peiran Wang, Yu Feng, Yuan Tian
Cryptography and Security
DKVE: Decentralized Key Validation for End-to-End Encrypted Messaging
Subin Song and Taekyoung Kwon
End-to-end encrypted messaging systems depend on authentic public key distribution to prevent man-in-the-middle (MitM) attacks. Current solutions present a stark trade-off: out-of-band (OOB) verification provides strong security but lacks scalability for large contact lists, while key transparency (KT) systems enable automated verification at high storage costs and operational complexity. We propose DKVE, a protocol that validates public keys through
privacy-preserving cross-validation within users' social graphs. When obtaining a contact's public key from a key server, clients query mutual contacts to verify they hold the same key, combining Oblivious Pseudorandom Functions (OPRF) and Oblivious Key-Value Stores (OKVS) to preserve
privacy of both queries and contact lists. DKVE employs a Sequential Probability Ratio Test (SPRT) to aggregate responses and detect server misbehavior with user-configurable error bounds. We evaluate DKVE through simulations on real social network
datasets, demonstrating DKVE can detect MitM attacks with exceeding 97% for strong-to-moderate-tie networks. The remaining 3% of cases require validation through alternative methods such as KT and OOB verification. Our proof-of-concept implementation confirms feasibility for background operation on commodity hardware, in terms of the latency and bandwidth. As DKVE can reduce the frequency of KT queries by two orders of magnitude, it enables fundamental architectural shifts: KT directories can migrate from fast but space-inefficient Merkle trees to space-efficient data structures like RSA accumulators. While DKVE cannot replace existing methods entirely – suffering from bootstrapping problems and degraded performance on weak-tie networks – it provides a practical complementary key validation mechanism, making secure messaging more deployable for billion-user systems.
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Cryptography and Security
Adaptive Evaluation of Out-of-Band Defenses Against Prompt Injection in LLM Agents
Praneeth Narisetty, Shiva Nagendra Babu Kore, Uday Kumar Reddy Kattamanchi et al. (+1 more)
Recent work (2024 to 2026) has converged on a strategy for defending tool-using LLM
agents against indirect
prompt injection: rather than training the model to refuse malicious instructions, enforce security outside the model with a deterministic policy that mediates the
agent's actions. Systems such as CaMeL, FIDES, Progent, RTBAS, and FORGE realize this with capabilities, information-flow labels, and reference monitors, and several report near-elimination of attacks on the AgentDojo
benchmark. We make two contributions. First, we organize these out-of-band defenses as instances of classical integrity protection (Biba), reference monitoring, and least privilege, yielding a structured comparison of what they do and do not cover. Second, we warn that every one of them is validated only on static
benchmarks (a fixed set of injection attempts), the same methodology that made in-band defenses look strong until adaptive, defense-aware attacks broke twelve of them at over 90% success; we specify the threat model and protocol an adaptive evaluation requires. We then run that protocol as an independent reproduction and extension of Progent's own adaptive-attack analysis, on AgentDojo, with an open-weight
agent (Qwen2.5-7B) self-hosted on a single H200, a setting its authors did not test. Averaged over three runs, the defense held: Progent cut mean attack success roughly sixfold (25.8% to 4.2%), and a hand-crafted adaptive attack did not raise it (2.6%). This is one small-scale data point on a weak model with a single black-box attack template; a stronger optimized (white-box GCG) attack remains open. The result is consistent with, but does not establish, the hypothesis that deterministic out-of-band enforcement is a harder target for an adaptive attacker than in-band detection.
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All authors Praneeth Narisetty, Shiva Nagendra Babu Kore, Uday Kumar Reddy Kattamanchi, Jayaram Kumarapu