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Computer Science Cryptography and Security

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Sunday 13 September

Cryptography and Security · Cross-listed from cs.AI

AI Deployment Accountability Engineering: A Vision for Accountable AI in Safety-Critical Socio-Technical Systems

Artificial intelligence systems are rapidly becoming critical components in healthcare, finance, public services, and other safety-critical domains. Yet the engineering practices used to evaluate these systems remain predominantly model-centric, emphasizing properties such as accuracy, robustness, fairness, and interpretability before deployment. These properties are necessary but insufficient once an AI system operates within an ever changing socio-technical environment characterized by distribution shifts, institutional constraints, human feedback loops, privacy requirements, and interactions among multiple AI agents. This vision paper introduces AI Deployment Accountability Engineering (ADAE), a proposed AI engineering subdiscipline concerned with establishing measurable, continuous, and actionable accountability for deployed AI systems. ADAE treats accountability as a deployment-layer property rather than solely as a property of an individual model. It seeks to determine whether an AI-enabled system continues to operate within acceptable risk limits, identify the contexts in which failures emerge, attribute failures across interacting technical and human components, translate technical failures into downstream consequences, and support timely intervention. We articulate a research agenda built around four interconnected pillars: structured discovery of context-dependent failure modes, privacy-preserving accountability measurement, system-level risk analysis for agentic AI, and translation of technical failures into operational, and institutional risks. The broader goal is to establish foundational principles, mathematical tools, and system architectures for accountable AI deployment across safety-critical applications.
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Cryptography and Security

Quantifying Observable High-Frequency Swapping on Arbitrum

Layer-2 rollups have reshaped Ethereum's transaction economy by replacing mempool competition with deterministic sequencing, sub-second block times, and negligible gas fees. While these properties suppress classical Miner/Maximal Extractable Value (MEV), they give rise to a new and previously unrecognized behavioral regime. In this paper, we introduce the concept of High-Frequency Swapping (HFS), referring to continuous single-hop swaps at machine cadence within decentralized exchanges. Despite its growing footprint, this phenomenon has not been systematically identified or quantified in prior work. We conduct a large-scale measurement of HFS on Arbitrum, using 18 months of full-chain data (Jan. 2023–Jun. 2024). Specifically, we construct a reproducible pipeline that isolates voluntary single-swap transactions, attributes them to the swapper level, and classifies HFS behavior through inter-arrival dynamics. The analysis uncovers 477 distinct HFS swappers responsible for nearly 30 million swaps and over $10^{11}$ USD in notional volume. Our study conducts a comprehensive empirical investigation of HFS from multiple perspectives. We begin with a global overview of activity patterns, and then examine temporal dynamics, swapper identity, token coverage, and venue concentration, and explore swap size, time gap, and order direction. Finally, we explore case-level behavior, including stablecoin arbitrage, CEX-DEX execution gaps, and short-horizon round-trip trading. Across these dimensions, we identify consistent structural regularities that distinguish HFS from conventional retail or arbitrage activity. This work provides a large-scale address-level empirical characterization of High-Frequency Swapping on Arbitrum and a broad empirical foundation for future research on decentralized market microstructure.
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All authors Shijian Chen, Ya Chen, Jing Cai, Catherine Liu

Cryptography and Security · Cross-listed from cs.SE

EchoFuzz: Empowering Smart Contract Fuzzing with Large Language Models

Smart contracts, serving as the cornerstone of decentralized applications, autonomously manage trillion-dollar digital assets, making them attractive targets for attacks. Fuzzing has emerged as a promising technique for detecting vulnerabilities in smart contracts, yet existing methods face two main challenges. (1) The logical gap in state transitions and combinatorial redundancy hinders effective tradeoffs between bug detection efficiency and state space exploration cost, leading to critical execution paths to be overlooked. (2) Rule-based sequence mutation strategies suffer from path redundancy and inadequate guidance from contract logic, resulting in performance bottlenecks that stall the exploration of in-depth vulnerability-oriented paths. To tackle these challenges, we propose EchoFuzz, an LLM-guided fuzzing framework introducing Vulnerable Function Call Sequences (VFCS) - minimal, behavior-preserving execution paths that expose bugs through key state transitions. EchoFuzz consists of two key procedures. First, we develop a chain-guided LLM approach, that combines static analysis with logical understanding to generate contract-specific VFCS candidates that eliminate combinatorial redundancy. Second, we adopt an iterative fuzzing strategy that uses LLMs with real-time feedback to adaptively steer fuzzer toward uncovered branches. Experiments show EchoFuzz outperforms state-of-the-art methods, achieving 29% higher branch coverage and detecting 62% more vulnerabilities. It also found 37 previously unknown vulnerabilities in real contracts, showing strong practicality.
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All authors Juanen Li, Peng Qian, Guanyan Li, Rui Wang, Peixin Wang, Zhiqing Tang, Fuchen Ma, Yuanliang Chen, Lun Zhang

Cryptography and Security · Cross-listed from cs.IT

Channel-Aware Selection of Folded Bloom Filters for Distributed Systems

Periodic Bloom-filter transmission can impose substantial overhead in communication-constrained distributed systems. Lossless compression preserves membership behavior but provides a single transmission size, whereas established OR folding produces smaller representations with higher false-positive rates (FPRs) while preserving the no-false-negative property. This paper investigates channel-aware selection among OR-folded representations. The sender retains an unchanged canonical filter, constructs a catalog satisfying a maximum FPR, and selects the FPR-qualified representation with the largest retained length supported by the communication resources available at each reporting opportunity. Unlike folding driven principally by cardinality and false-positive constraints, selection is driven by time-varying communication conditions. Using two phishing URL datasets, the framework is evaluated under Five-State Markov Capacity, Gilbert–Elliott burst-error, and Rayleigh block-fading models. Channel-aware folding improves communication efficiency and receiver freshness relative to complete-filter and lossless-compression baselines when communication opportunities vary substantially. Under the more favorable Gilbert–Elliott model, it remains competitive in efficiency while maintaining the freshest receiver state. These results show that FPR-qualified folded views provide useful transmission operating points when a recent lower-fidelity update is preferable to delaying a larger representation.
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Cryptography and Security · Cross-listed from cs.DS

Private Graph Property Testing

Graph property testing asks whether a massive graph satisfies a given property, or is far from doing so, using only a sublinear number of queries to the graph. Since property testers typically inspect only a small, randomly sampled portion of the input, they appear naturally compatible with differential privacy and privacy amplification by subsampling. Despite this, few results link these two fields. We initiate a systematic study of differentially private graph property testing with the goal of designing efficient testers with formal privacy guarantees in the dense and bounded-degree graph models. We develop new privacy amplification theorems for several widely used graph-sampling procedures such as induced subgraph sampling, random walks and k-disc sampling. We then leverage these privacy amplification techniques to design a private canonical tester in the dense graph model, as well as private bipartiteness testers and subgraph freeness testers in the dense and bounded-degree graph models. Finally, using the new privacy amplification theorem for k-disc sampling, we prove that every property of hyperfinite graphs is privately testable. The resulting query complexities of our private testers are comparable to those of their non-private counterparts.
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All authors Hendrik Fichtenberger, Abigail Gentle, Tamalika Mukherjee, Sayantan Sen

Cryptography and Security

Cryptanalytic Extraction of Neural Networks Without Known Architecture Assumption

Cryptanalytic model extraction aims to reconstruct a functionally equivalent model through black-box interactions with the victim model. Under the fundamental assumption that the network architecture is completely known, existing attacks achieve the goal by recovering the model parameters. In this paper, we explore whether this assumption can be removed practically. Focusing on ReLU fully connected networks, which are widely studied in this field, we propose a guess-and-determine framework that jointly recovers the network architecture (including network depth and hidden-layer dimensions) and the model parameters. This framework is based on a simple yet effective high-level idea: after designing a parameter recovery attack under the known-architecture assumption, we can analyze the architecture-sensitive traces observed during parameter recovery to recover the network architecture. We identify two such traces in differential extraction attacks: (i) a zero suffix in the merged weight vectors produced by signature recovery, whose length reveals the hidden layer dimension; and (ii) an equality pattern in the preimage-based sign recovery, which occurs only under the true hidden layer dimension. These two signals give rise to two routes for network architecture recovery. For the second-to-last layer, we further propose two methods, one for identifying it, and one for recovering its dimension. Practical end-to-end attacks are implemented on a wide range of ReLU neural networks, including both expansive and non-expansive networks. To the best of our knowledge, this is the first time the feasibility of achieving functionally equivalent extraction on deep neural networks, after removing the known-architecture assumption, has been demonstrated in practice.
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All authors Yantian Shen, Yi Chen, Anyu Wang, Hongbo Yu, Xiaoyun Wang

Cryptography and Security

Fusing Spectral Signatures and Activation Clustering for Backdoor Detection in Healthcare Imaging Models: Method, Implementation, and Evaluation

Machine learning models are increasingly deployed in healthcare imaging pipelines for diagnostic support, and training-time attacks against them are a named sector-level concern: healthcare-sector guidance identifies model poisoning and adversarial attacks as threats requiring dedicated defenses, while federal policy directs expanded AI vulnerability-detection tooling to critical infrastructure operators such as rural hospitals. Spectral signature analysis and activation clustering are two established backdoor detection methods routinely evaluated as independent baselines, but their outputs are not ordinarily combined, and reported detection performance on medical imaging benchmarks remains sparse relative to the natural-image setting. This paper contributes three things: a score-level fusion rule combining per-class spectral ranking with activation-clustering flags into a single per-sample poisoning score and a model-level agreement statistic; an open-source implementation of the resulting eight-stage pipeline; and an evaluation of that pipeline against synthetically poisoned variants of a public medical imaging benchmark and CIFAR-10 at four poisoning rates (0%, 1%, 5%, 10%) over five seeds each, measuring each detector alone against the fusion. On the medical benchmark, the fused detector reaches AUROC >= 0.99 at every nonzero poisoning rate tested. On CIFAR-10, fusion does not uniformly help: at 10% poisoning, activation clustering's true-positive rate collapses to 0.000 and spectral AUROC independently degrades to near-chance (0.545), despite a 97.2% attack success rate confirming the backdoor was fully installed. The fused score, a weighted combination of both signals, inherits this joint failure. Detection output is expressed in NIST AI RMF Measure-function and MITRE ATLAS terms, so findings are reported in the vocabulary security and compliance teams already use.
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Cryptography and Security

Policy-Governed Post-Quantum Migration for Legacy Microservices Using Ephemeral Sidecar Architectures

The fast development of quantum computing represents a big risk to classical cryptography that is commonly used in cloud native and microservice based enterprise systems. Traditional cryptographic primitives are closely linked to legacy microservices and it is both intricate, hazardous, and disruptive to straight up migrate to post-quantum cryptography (PQC). In a bid to overcome these issues, this research presents a PolicyGoverned Post-Quantum Migration through Ephemeral Sidecar Architectures (PG-PQMES), a framework of dynamic and reversible migration that allows transparent adoption of PQC without any modifications in the legacy code of applications. The architecture is a combination of three coherent layers, including Ephemeral Crypto Sidecar Layer which injects the runtime cryptography, Policy Governance Layer which manages the migration centrally, and Migration Safety and Observability Layer which measures the performance and rolls back automatically. An innovative Policy-Governed Ephemeral PQ Migration (PG-EPM) algorithm is proposed to maximize the performance, compliance, and trust-based migration. In simulated environment of microservices, experimental assessment shows that the time of migration, service downtime, overheads of latency, and rollback recovery time are substantially reduced using the current migration strategies. The findings show that a sidecar-based migration strategy that is policy-based offers a viable, scalable, and enterprise-scale migration to a secure post-quantum transformation.
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Cryptography and Security

Enc53: DNSSEC-Anchored Stateless Tickets for Post-Quantum Authoritative DNS

DNSSEC authenticates RRsets, but does not provide endpoint authentication or channel security. DNS-over-TLS (DoT) and DNS-over-QUIC (DoQ) can facilitate such needs, but were designed for the stub-to-resolver hop, where stable long-lived connections amortize the expensive initial setup. The recursive-to-authoritative path's high fan-in and nonuniform per-resolver query frequency invert said dynamics. Post- quantum primitives further sharpen this mismatch: an ML-DSA WebPKI certificate chain crosses TCP's initial window, a cold PQ DoQ may incur up to about 140 times the total bytes of the same query over UDP. A survey of TLD and 2LD nameservers further bounds connection lifetimes, with almost half surveyed imposing limits on even non-idle connections. We present Enc53 – a stateless session ticket protocol enabling efficient authenticated authoritative DNS encryption. Enc53 splits DNS encryption into 2 phases: a short-lived, DNSSEC-anchored, TLS- authenticated provisioning on the initial query in the 1st, and a steady state of 1-RTT AEAD-encrypted UDP DNS queries in the 2nd. Enc53 is server-side stateless: recursive resolvers hold the traffic secret and session ticket, authoritative nameservers hold only a symmetric STEK. We implemented Enc53 in Knot DNS. After provisioning, a steady state Enc53 exchange costs about 570 B – roughly 3 times a plain UDP query – and lands within 1 ms of the unencrypted UDP baseline. Resumed PQ-ADoT pays 7.7 times the bytes and 3 times the latency; resumed PQ-ADoQ pays 10 times the bytes for the same latency. When evaluated against a root server query trace, Enc53 achieves 2-fold compute efficiency over ADoT/ADoQ, 3-fold memory efficiency over ADoT, and 12-fold memory efficiency over ADoQ. Finally, when deployed in conjunction with FN-DSA-512 PQ-DNSSEC, the joint Enc53-DNSSEC UDP datagram remains below the 1232B buffer limit.
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Saturday 12 September

Cryptography and Security · Cross-listed from cs.LG

Information Design Against Gaming and Learning Adversaries

A principal who deploys a binary classifier with an abstention option must decide which queries the mechanism abstains on. The right choice depends on the adversary. A gaming adversary already knows the classifier and tries to manipulate features across the boundary, so the principal does best by abstaining on queries close to that boundary. The same boundary-localizing rule is the worst possible choice against a learning adversary who does not know the classifier: each abstention now tells the adversary that the boundary is nearby, which is enough to drive a binary search. We analyze this tension. The two natural defenses, abstaining at a fixed rate and abstaining near the boundary, are Blackwell-incomparable: neither can be simulated by post-processing the other's responses. The number of queries needed to reconstruct the boundary to error $\eps$ is $\tilde\Theta(d/\eps)$ under the first defense and $\Theta(d \log(1/\eps))$ under the second, where $d$ is the VC dimension of the classifier family and $\tilde\Theta$ suppresses factors polylogarithmic in $d$ and $1/\eps$. The first rate is a worst case over query distributions; no reconstruction algorithm can close the gap at the distributions that attain it. We characterize the Pareto frontier between the two defense objectives, and confirm both rates on seven binary-classification tasks spanning tabular, image, and language-model-feature inputs: label-plus-counterfactual access extracts the boundary with up to $200\times$ fewer queries than a published label-only baseline.
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Cryptography and Security

Transparent Identity Verification Approach Using MPC and Efficient Credential Status Handling

A secure and privacy-preserving identity verification process is essential for digital ecosys- tems. Current eKYC frameworks that rely on Zero-Knowledge Proofs (ZKPs) face high computational cost, rigid circuit design, complex integration, and expensive on-chain verification. The W3C 2021 BitString- based credential status mechanism also suffers from inefficient updates and poor scalability in large- scale deployments. We propose a transparent and cost-effective identity verification framework based on Multi-Party Computation (MPC). It enables private off-chain code execution and produces runtime proofs anchored to a blockchain. The framework introduces a multidimensional bit-matrix model with efficient compression. Using ZSTD, the credential data is reduced to 76 bytes compared to 140 bytes with GZIP, cutting storage and bandwidth costs. The system also supports fine-grained status updates and Layer-2 blockchain anchoring for tamper-evident, low-cost verification. The system employs reusable verifiable presentations (VPs) with unique access tokens, enabling cost-free verification and stronger access control. Selective disclosure preserves user control and strengthens privacy. Finally, the system integrates SHA3 hashing and Falcon post-quantum signatures. This guarantees robustness against quantum attacks, transparency, and scalability. It is a future-proof solution for national-scale identity verification, as demonstrated by experimental findings and security studies that validate its robustness and applicability.
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All authors Istiaque Ahmed, Shoji Kasahara, Kentaroh Toyoda, Tadashi Nakano, Thi Hong Tran

Cryptography and Security

PixCrypt: Fast Fine-Grained FHE with Range-Aware Caching

Many analytics tasks require secure computation over encrypted data. In particular, fine-grained data such as pixel-level images require higher precision, as every pixel can directly affect outcomes in tasks like tumor segmentation and anomaly detection. While Multi-Party Computation (MPC) is interactive, Differential Privacy (DP) protects only aggregate values, and Partially Homomorphic Encryption (PHE) lacks multiplicative support, none of them can efficiently handle fine-grained data analytics. Fully Homomorphic Encryption (FHE) uniquely enables arbitrary operations on encrypted pixels but remains computationally expensive, posing significant challenges for both software and hardware accelerators. We present PixCrypt, a caching-based acceleration mechanism for fine-grained fully homomorphic encryption. PixCrypt replaces expensive fresh ciphertext generation with cache retrieval and coefficient-level operations across CKKS, BFV, and BGV, while randomized reconstruction ensures that ciphertexts do not repeat. Its linear noise growth reduces the need for bootstrapping and lowers NTT load, improving hardware accelerator efficiency. This design yields up to 35x faster fine-grained encryption and maintains IND-CPA (Indistinguishability under Chosen Plaintext Attack) security. Experiments on five real-world pixel-level image processing tasks show that PixCrypt significantly improves the practicality of FHE for privacy-preserving analytics.
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All authors Chao Wang, Shubing Yang, Xiaoyan Sun, Yan Bai, Jun Dai, Dongfang Zhao

Cryptography and Security

A Graph-Based Framework for Extending Metric Differential Privacy Mechanisms

Metric differential privacy (mDP) is well suited to structured secret domains, but directly constructing utility-aware mechanisms over large or fine-grained domains is often computationally prohibitive. We study extension-based mDP design, where a mechanism is first specified on a finite set of seed records and then extended to a larger target domain. To our knowledge, this is the first work to systematically formulate extension as a general design paradigm for mDP rather than a method-specific construction. We present a graph-based extension framework, identify three requirements for correctness, local mDP constraints, overlap consistency, and successor-level mDP preservation, and show that, under these conditions, the induced global mechanism is well defined and satisfies $\epsilon$-mDP on the target domain. We further instantiate the framework with a tree-based extension algorithm for multi-resolution grids, where multi-dimensional extension is realized through one-dimensional interpolation and dimension-wise composition. Experiments on road-map datasets demonstrate that our approach achieves a strong utility-scalability trade-off while preserving exact mDP guarantees.
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Cryptography and Security

Same Name, Different Server: A Security Census of Silent Drift in the Model Context Protocol Ecosystem

The Model Context Protocol (MCP) has become the common interface through which large language model applications reach external tools, and its public registry now distributes thousands of community-built servers with little of the vetting infrastructure that mature package ecosystems have accumulated. This paper reports a census of that ecosystem. We harvested the full public MCP registry (21,643 servers, 72,606 version records, August 2026 snapshot), fetched source code for 14,353 servers, and applied a pattern-based scanner covering an eight-class threat catalogue whose accuracy we measured against 414 hand-labeled findings. Observed prevalence is dominated by unauthenticated network exposure (9.57% of scanned servers); after correcting each class by its measured precision, 11.14% observed high-severity prevalence reduces to roughly 7.6%. The central finding concerns instability rather than any single weakness: 51.1% of multi-version servers changed what they advertise between versions, 40.6% did so silently, and 4.2% redirected their remote endpoint to a different host while keeping their registry identity, a change the protocol never surfaces to installed clients. Silent drift is associated with nearly threefold higher odds of a high-severity finding (OR = 2.96, 95% CI [2.56, 3.42]). Popularity offers only weak protection (OR = 0.78 per unit of log stars), so star counts are a poor proxy for safety. We derive concrete recommendations for registry design, client-side pinning, and scanner triage, and release an anonymized artifact.
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Cryptography and Security

The Deception Delta: Adversarial Evaluation of LLM-Based Smart Contract Bytecode Forensics

Large language models are increasingly used in blockchain forensic investigations to interpret unverified smart contract bytecode. Their robustness has not been systematically tested against contracts adversarially designed to mislead analysis. We evaluate 22 frontier models on 13 purpose-built contracts (9 deception vectors, 4 controls) across six prompt strategies, yielding 8,528 analyzable non-refusal runs against contracts with documented ground truth. A calibrated LLM-as-judge pipeline, supported by two judge-independent metrics and 50 human gold-standard labels, shows that adversarial deception reduces drain detection by 20.0 percentage points (95% CI: [17.2, 22.8]) relative to functionally matched controls. Structural camouflage via multi-hop call chains, XOR-masked selectors, and storage-loaded drain parameters resists detection across nearly all models. Beyond non-detection, we identify rationalization: models correctly describe the hidden drain mechanism but accept the contract's deceptive framing and dismiss it as benign, yielding positive but incorrect evidence of safety. Simple guard instructions provide no aggregate benefit and destabilize individual models in both directions. Structural deception is largely insensitive across the six tested prompt strategies, more consistent with a capability limitation than with a simple prompting problem. Only five models from two providers exceed 50% detection. Under our single-shot, raw-bytecode-only protocol, current LLMs are not reliable standalone forensic tools. Our central claim does not extend to multi-turn, tool-augmented, source-aware, or decompiler-in-the-loop workflows; a source-code boundary check is reported as an explicit subset analysis rather than as part of the main evaluation.
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Cryptography and Security

SkillSecurer: Detecting and Patching Prompt-Injection Vulnerabilities in AI Agent Skills

Agent skills extend AI agents with reusable instructions, scripts, and configuration, but are also open to new attacks to influence an agent's decisions and actions. To address these risks, we present SkillSecurer, a fully agentic framework for generating, detecting, localising, and remediating security risks in agent skills. Its red agent generates context-compatible injections across nine threat types while recording the exact modification; its blue agent analyses complete skill packages, produces grounded evidence, and proposes patches. For controlled instances, a verifier compares findings and patches with the recorded injection, enabling injection-level evaluation. We thoroughly evaluate SkillSecurer by selecting the best backend LLM, comparing it with competitors, and manually cross-validating each evaluation stage. With its best performing backend, SkillSecurer is the only scanner to achieve a 100% injection detection rate. Next, we analyse popular skills from skills.sh, finding latent vulnerabilities in more than 17% of the skills examined. Testing some of those skills, we trigger actual incidents, showing the risks of running unverified skills. Our results show that context-aware LLM analysis can provide reliable injection localisation and actionable remediation beyond skill-level flagging alone.
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All authors Donato Mecca, Alberto Verna, Youness Bouchari, Nikhil Jha, Marco Mellia

Cryptography and Security

AGENTQ: Quantization-Conditioned Backdoor Attacks on LLM Agents

Quantization is one of the default deployment paths for open-weight LLM agents, but it is not behavior-preserving: an adversary can release a full-precision checkpoint that passes audits yet misbehaves once quantized, termed as quantization-conditioned attack (QCA). Prior QCA work targets free-text generation, where harm is mediated by a human reader. In contrast, the agentic setting poses a more severe risk: the triggered payload is a structured function that can be executed without human oversight. We present the first study of QCA against LLM agents. We find that directly adapting prior backdoor-injection methods can produce malicious behavior after quantization, but substantially degrades benign utility, rendering the resulting attacks impractical. To understand the true upper bound of the threat, we propose AGENTQ, an attack framework that combines layer-banded LoRA injection with partial-PGD repair over a multi-codebook quantization-equivalence class. AGENTQ preserves normal agentic capability while concentrating malicious behavior in the quantized model. Across three trigger-action pairs and three codebooks (NF4, FP4, INT8), AGENTQ reaches up to 100% post-quantization attack success rate with minimal loss of benign utility, underscoring the need to make quantization-aware safety evaluation a standard requirement before open-weight agents are deployed.
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Cryptography and Security

Symmetric Models for Syndrome Decoding

This paper introduces a new polynomial model for the exact variant of the Syndrome Decoding Problem (SDP) in the binary case. The model is based on elementary symmetric polynomials. We estimate the computational complexity of solving the corresponding polynomial system by establishing bounds on the degree of regularity and on the solving degree of the ideal associated to the model. The complexity estimate is lower than for previous polynomial models. We also provide a variant of the model whose complexity depends directly on the specific instance of the SDP and is lower than for the first model. Finally, we discuss how to apply our approach to solve other variants of the SDP.
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Cryptography and Security

A High-Throughput FPGA Architecture for Real-Time TCP-SYN Scan Detection

TCP-SYN port scanning often precedes cyber-attacks, and early detection of scanner fingerprints embedded in packet headers can provide timely intrusion alerts. Existing approaches are either too computationally expensive for line-rate operation or limited to offline analysis. This brief presents a lightweight FPGA architecture for reconfigurable line-rate fingerprint detection, where each fingerprint is compiled into a shallow Boolean LUT tree, enabling parallel evaluation with constant two-cycle latency regardless of fingerprint count, while resource cost grows linearly with fingerprint count. This detection core is decoupled from a MAC-layer frontend that performs streaming field extraction with no frame buffering or higher-layer state, allowing deployment across different line rates by modifying only the frontend. A Python framework automatically compiles Boolean expressions into synthesizable HDL, eliminating manual RTL changes. For TCP-SYN port-scan fingerprint detection, the architecture uses approximately 0.5% LUTs at 10 Gbps on a Versal VCK190 for 18 deployed fingerprints, with capacity for over 2,000 concurrent fingerprints, and under 2.5% on a Virtex-6 at 1 Gbps, with a detection latency of 10 ns at both rates, three to four orders of magnitude below typical per-packet processing latency in software intrusion-detection systems. The system was cross-validated against a software re-implementation on an 8-hour production packet trace, confirming detection correctness with zero false positives/negatives.
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All authors Faisal Saeed, Mohammad Fahad, Ayesha Javaid, Christian Doerr, Muhammad Ali Siddiqi

Cryptography and Security

Confuse the Model, Control the Flow: Understanding and Mitigating Privacy Leakage from LLM Agents with Information Flow Control

Personal AI agents built on large language models (LLMs) are increasingly given access to a user's private data and communications in order to provide personalized assistance. This access creates a persistent privacy risk: the agent must decide whether a given sensitive information should be disclosed to a particular party. Existing defenses address this by making the agent's backend LLM more privacy-preserving through stronger system prompts, training, or explicit consent-checking procedures, but this approach has a structural challenge: whenever enforcement is a judgment the LLM makes over the same conversational context an adversary controls, the enforcement mechanism and the attack surface coincide. We demonstrate this against existing defenses with three new attacks that require only ordinary agent interaction and no prompt injection: Collaborative Workspace Lure reframes an extraction attempt as collaborative work; Semantic Obfuscation Attack induces disclosure through omission rather than through anything the agent writes; and Channel Decoupling Attack splits the extraction request and the disclosure across independent channels. All three achieve substantially higher leak rates than the attacks these defenses were originally designed to withstand. Guided by this observation, we present FLOWSEAL, a defense that enforces confidentiality through a tool-level interceptor outside the LLM's context, grounded in data provenance and an information-flow-control lattice with controlled declassification. Evaluated across three benchmarks, five prompt-based baselines, and eight attacks, including a real agent executing live tool calls through MCP, FLOWSEAL reduces leak rates to near zero (e.g., 52.2% to 0.5% against Collaborative Workspace Lure) while preserving task utility, regardless of the underlying LLM backend.
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All authors Minsun Shim, Ramisha Raida Karim, Ruthwik Jakkula, Kaiwen Zhou, Xin Liu, Xin Eric Wang, Zhou Li

Cryptography and Security

Enforcement of In-Kernel Stateful Security Policies via eBPF

Many attacks against workloads running on multi-tenant systems are multi-step and history-dependent: sequences of innocuous operations whose malicious nature emerges only over an execution trace. Defending against them requires security policies that are stateful, are enforced within the kernel, and have a precise semantics. Currently deployed proposals fail on at least one count: kernel's built-in syscall filtering and classical MAC frameworks are stateless, while current eBPF-based tools express their policies through ad hoc YAML rules that cannot capture temporal relations among events, and whose semantics is defined only by the implementation. We present BPFence, an in-kernel runtime-verification framework that satisfies the properties above. BPFence provides a policy language with a formal semantics that can express temporal relations among events. It also provides a type system that statically distinguishes events the kernel can control from those it can only observe. Every well-typed policy is compiled into a finite-state monitor proved correct with respect to its semantics, and then into eBPF programs that run inside the kernel. We evaluate BPFence on seven case studies drawn from real-world attack patterns, and on a set of micro- and macro-benchmarks to show that the enforcement overhead remains compatible with production deployment.
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Cryptography and Security

When Malicious Instructions Persist: Persistent Memory Poisoning Attack on Harness-Based Agents

Harness design has transformed the development of LLM-based agents by integrating memory, tool use, and runtime control. However, this design also introduces security and privacy risks because malicious instructions from external sources may be written into persistent memory and persist across sessions. To study this risk, we propose PMPA, a Persistent Memory Poisoning Attack against harness-based agents. PMPA embeds malicious instructions into benign external sources and induces the victim agent to write them into persistent memory without directly accessing to the agent framework. Once stored, the poisoned memory can be retrieved in later sessions, triggering additional malicious actions and causing privacy leakage. We evaluate PMPA on OpenClaw and Claude Code across different backbone LLMs, input modalities, and trigger scenarios. Across all settings, PMPA achieves average Injection Success Rate (ISR) and Cross-session Attack Success Rate (C-ASR) of 73.7%/ 55.5% on OpenClaw and 66.9%/ 81.7% on Claude Code, while preserving benign task performance on both systems. We further evaluate a targeted prompt-level defense and find that it can reduce memory injection in many settings, but provides limited protection once the persistent memory has been poisoned.
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Cryptography and Security

PriMobiBench: Characterizing Visual Privacy Leakage in VLM-Driven Mobile GUI Agents

Mobile GUI agents increasingly rely on Vision-Language Models (VLMs) to automate smartphone tasks by interpreting screenshot streams. However, this design introduces serious and underexplored privacy risks, including direct leakage of sensitive on-screen information and unintended user profiling. The absence of standardized benchmarks makes it difficult to quantify these risks in realistic mobile agent workflows. To address this gap, we propose PriMobiBench, the first benchmark for systematically evaluating privacy leakage and visual profiling in screenshot-driven mobile agents. It provides a unified pipeline for data generation, agent trajectory construction, and multi-model evaluation. We also introduce MobiLeak, a dataset of execution traces from 16 apps, covering 25 privacy attributes with 2,960 embedded privacy instances. Our results reveal substantial risks: (1) VLMs can directly extract sensitive information with up to 82.5% success rate; (2) beyond explicit leakage, they can infer user profiles from aggregated visual evidence with approximately 70% success. We further propose a mitigation that masks privacy-sensitive but task-irrelevant UI elements before cloud processing, reducing profiling success by up to 58% with only approximately 8% performance loss. Overall, our work provides the first systematic benchmark for visual privacy risks in mobile GUI agents, demonstrates that both leakage and profiling are feasible at a highly concerning level, and offers a practical direction for mitigation.
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All authors Qihang Cen, Tianshuo Cong, Da Song, Xinlei He, Jiaxing Song, Ke Xu, Qi Li

Cryptography and Security

Exploring Automated Vulnerability Identification in JavaScript Code Using Large Language Models

JavaScript powers approximately 98.8% of all websites, making vulnerabilities in its code a significant security risk, yet existing detection approaches such as Static Application Security Testing (SAST) tools often fail to identify many real-world vulnerabilities when applied to isolated code snippets. This paper presents an empirical study of Large Language Model (LLM)-based vulnerability identification for JavaScript programs, evaluating three LLM families (Gemini 1.5 Flash, GPT-4o Mini, DeepSeek-R1-Distill-Llama-8B) across multiple prompting strategies (zero-shot, chain-of-thought, few-shot) and fine-tuning approaches on a dataset of 1,125 JavaScript code snippets spanning five Common Weakness Enumeration (CWE) categories: Injection (CWE-74), OS Command Injection (CWE-78), Cross-Site Scripting (CWE-79), SQL Injection (CWE-89), and Uncontrolled Resource Consumption (CWE-400). Our experiments show that LLMs substantially outperform traditional SAST tools on snippet-level vulnerability identification, with a fine-tuned Gemini 1.5 Flash model achieving 60% detection accuracy compared to near-zero performance from rule-based analyzers. We find that fine-tuning improves accuracy from 29% to 60%, Chain-of-Thought prompting benefits reasoning-capable models such as GPT-4o Mini, few-shot prompting is effective for polymorphic vulnerabilities such as Cross-Site Scripting, and performance varies across vulnerability categories, reaching up to 84% accuracy for structured vulnerabilities such as SQL Injection. These results indicate that LLMs provide a practical approach for automated vulnerability identification in JavaScript code, particularly when combined with task-aligned supervision, though they should complement rather than replace existing security analysis workflows due to limited recall and uneven performance across vulnerability types.
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All authors Manit Kaushik, Ishir Bhardwaj, Pranav Gupta, Pankaj Jalote, Arun Balaji Buduru

Cryptography and Security

PQLN: Post-Quantum Security for the Bitcoin Lightning Network's Off-Chain Surfaces

A cryptographically relevant quantum computer will break the elliptic-curve cryptography behind Bitcoin and its Lightning Network, the most widely used payment channel network. Even a post-quantum consensus upgrade of Bitcoin would not cover Lightning's off-chain surfaces, so its gossip, peer transport, invoices, payment onions, and offers need separate protection. An adversary can already record Lightning's encrypted traffic today and decrypt it once such a computer exists. Lightning can therefore move to post-quantum cryptography now, without waiting for Bitcoin, and stop such harvest-now-decrypt-later attacks along with node impersonation, invoice forgery, and payment deanonymization. In this paper, we propose PQLN, a hybrid post-quantum extension of Lightning that protects all of these surfaces with the lattice-based standards ML-DSA and ML-KEM. PQLN distributes post-quantum node identities through Lightning's gossip, hybridizes the transport handshake, adds post-quantum signatures to invoices, commits post-quantum keys in offers, and makes payment onions hybrid. Since post-quantum material is much larger than its elliptic-curve counterpart, we introduce techniques that fit it into Lightning's existing message formats and size limits. We analyze the security of PQLN against a quantum adversary and implement it in rust-lightning, a major Lightning implementation. Our evaluation with real Lightning nodes shows that PQLN nodes interoperate with unmodified nodes. The added cryptographic operations take at most 0.33 milliseconds, and the main cost is communication, since gossip data grows about tenfold with ML-DSA and about fourfold with the smaller Falcon. To our knowledge, PQLN is the first post-quantum design, implementation, and evaluation for Lightning.
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All authors Ahmet Kurt, Abdul-Salem Beibitkhan, Yacoub Hanna, Abdullah Aydeger

Cryptography and Security · Cross-listed from cs.SE

TyPatch: Transforming Patches into Typestate Rules for Kernel Bug Detection

Historical Linux kernel patches capture defect knowledge that applies beyond their original repair sites. Recent work has shown that large language models (LLMs) can generate static-analysis checkers from historical patches and use them to uncover new kernel bugs. However, complete-checker generation requires the model both to recover the defect semantics expressed by a patch and to implement sophisticated program-analysis machinery, including object tracking, alias analysis, path-state maintenance, and interprocedural propagation. Coupling these responsibilities in a single end-to-end code-generation task can turn a simple defect rule into an unstable and expensive analyzer-implementation problem. To address this problem, we present TyPatch, which decouples patch-specific defect semantics from analyzer implementation. An LLM translates each patch into a typestate rule specifying its tracked object, actions, guards, transitions, and violations. A shared backend then executes these rules, binding their actions to program events, tracking object identity across aliases, propagating typestate along program paths, and producing reports for all rules. On Linux v6.16, TyPatch finds 559 distinct bugs, 121 of which have been confirmed by kernel developers. In a matched 38-patch comparison with the state-of-the-art complete-checker construction workflow, TyPatch uses 88.3-90.1% fewer generation tokens, while its initial report pools achieve 3.42-14.95$\times$ the precision of those produced by that workflow.
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Cryptography and Security

PatchRisk: Forecasting Future Vulnerability Exposure in Open-Source Dependency Networks

Open-source software ecosystems are web-scale dependency networks. A downstream package can become exposed to security risk not because its own source code changes, but because one of its transitive dependencies later receives a vulnerability advisory. Existing vulnerability-detection work often focuses on whether code is currently vulnerable or whether a known vulnerable dependency is already present. We study a different problem: future transitive vulnerability exposure. Given a package-version dependency graph observed at release time, the task is to predict whether any non-root dependency will receive a vulnerability advisory within a future horizon. This problem is important for Web intelligence and software supply-chain security because it supports proactive dependency triage before future exposure is visible. It is also easy to evaluate incorrectly: current vulnerable dependencies can leak the label, and different versions of the same root package can create package-level memorization across train and test splits. We therefore construct PatchRisk, a leakage-aware benchmark from Open Source Vulnerability advisories and deps.dev dependency graphs for npm and PyPI. The benchmark uses filtration-aware labels, package-disjoint evaluation, temporal testing, and nested 1K, 3K, 5K, and 10K sampling scales. The largest cleaned setting contains 9,007 root package-version graphs spanning 4,157 root packages. We evaluate three feature families: TimeOnly, GraphStruct, and HistoryGraph. On the 10K temporal-test benchmark, HistoryGraph improves AUPRC over the strongest TimeOnly baseline from 0.351 to 0.640 for 90-day forecasting and from 0.473 to 0.813 for 365-day forecasting. The improvement remains stable across smaller scales and package-group shuffle robustness tests.
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Cryptography and Security

Basis Rigidity of the AES S-box and Generic Rigidity of Inversion under Affine Transformations

The AES S-box is constructed from finite field inversion followed by a fixed affine transformation. Since inversion possesses intrinsic Frobenius symmetries among its coordinate realizations, we study how these basis symmetries are altered by outer affine transformations. We first develop a deterministic rigidity criterion for transformed inversion and apply it to the AES S-box. This shows that the linear part of the AES S-box affine transformation alone makes the transformed inversion map basis rigid. We then investigate the corresponding generic problem when the outer invertible linear transformation varies. The existence of a nontrivial linear stabilizer is reduced to a conjugacy problem for semilinear candidates arising from two sided linear equivalences of inversion, which we characterize in terms of relative norms and Frobenius orbits. We also determine the dimensions of the associated centralizer algebras exactly. These structural results imply that, for a uniformly chosen outer linear transformation, the probability that the linear stabilizer is nontrivial is bounded by $2^{-\Omega(n^2)}$, with sharper finite dimensional bounds obtained from the exact conjugacy condition. Computational experiments independently verify the AES rigidity result, the conjugacy and centralizer formulas, and the finite dimensional estimates in small dimensions.
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Cryptography and Security

EI-DDLGN: Efficient Encrypted Inference with Deep Differentiable Logic Gate Networks under TFHE

Privacy-preserving inference via Torus Fully Homomorphic Encryption (TFHE) provides strong protection for sensitive data in outsourced deep learning applications. However, most TFHE-compatible neural network frameworks remain based on arithmetic neural architectures, resulting in high inference latency due to programmable bootstrapping (PBS), accumulator growth, and circuit bit-width sensitivity. In this work, we investigate Deep Differentiable Logic Gate Networks (DDLGNs) as a Boolean-native alternative for encrypted inference under TFHE. Because DDLGNs learn Boolean computations directly and discretize into fixed logic gate networks, their inference procedure is naturally aligned with TFHE's Boolean execution model and avoids arithmetic accumulation in hidden layers. We present EI-DDLGN, the first in-depth study of TFHE-based DDLGN inference, and characterize how encrypted execution cost depends on model size, learned Boolean-function distribution, and propagated wire status. We also introduce Model-Fixed-Wire PBS Bypass (MFW-PBS Bypass), a semantics-preserving execution strategy that eliminates unnecessary PBS operations without modifying the learned network topology. Evaluations across 72 depth-width configurations on MNIST, FashionMNIST, and UCI Phishing show that DDLGNs constitute an efficient alternative to arithmetic TFHE inference, achieving substantially improved accuracy-latency trade-offs. Notably, on MNIST, EI-DDLGN-Small matches the accuracy of QAT-FCNN-4 while reducing encrypted inference latency by 13.4x. Our implementation is available at https://github.com/Carleton-SCI/EI-DDLGN
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Friday 11 September

Cryptography and Security

Mind the Gap: Detecting Description-Execution Mismatch Attacks in DAO Governance

Decentralized autonomous organizations (DAOs) change protocols through a proposal-based process: initiators submit a proposal, members vote on it based on its natural-language description, and if it passes, the project executes the code behind it. This process is inherently vulnerable to deceptive proposals, where the described intent and the actual code execution mismatch. A malicious proposer can submit a benign-looking description to pass voting while the executed code transfers funds or seizes control of the protocol, which we call a Description-Execution Mismatch (DEMI) attack. We present the first systematic framework for DEMI detection in real DAO governance. First, the diversity of DAO deployments makes a unified, scalable analysis difficult; we address this with a DAO-agnostic simulation framework that builds a per-DAO governance profile from historical on-chain transactions and then drives each new proposal through the full governance lifecycle to obtain its execution behavior. Second, free-form descriptions and structured execution traces are hard to compare; we address this with an evidence-mapping paradigm that requires an LLM to locate explicit per-action textual justifications rather than issue a holistic judgment, substantially improving precision and recall over direct querying. On a large-scale dataset of real-world Ethereum DAO governance, our simulation derives execution results for 92.7% of active DAOs and 89.3% of executed proposals, far exceeding existing platforms. Our detector reaches 81.7% mean precision and 98.3% mean recall under stratified cross-validation, and evidence mapping generalizes across LLM vendors rather than depending on one model. Under a systematic red-team/blue-team evaluation, the Robustness Guard defends most adaptive attacks even against an adversary that knows the detector, and this robustness generalizes to held-out proposals.
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All authors Bowen Cai, Nanzi Yang, Weiheng Bai, Youshui Lu, Yajin Zhou, Kangjie Lu