Cryptography & Security · Mon, Nov 2, 2026

arXiv Cryptography and Security (cs.CR) and the IACR Cryptology ePrint Archive.

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arXiv cs.CR · cs.AI · cs.CL

Do Agents Still Follow the Rules? Benchmarking Rule Compliance under Agent Context Compaction

In briefDo Agents Still Follow the Rules? Testing Rule-Following After Context Compression

SummaryLLM agents compress long histories to fit their context windows, but the compressed context must still keep the rules that govern later actions. The authors introduce ARCBench, a configurable benchmark built on the open-source pi agent harness that measures rule compliance from actions taken during execution. They find that compression rarely deletes the rule, and most post-compaction violations occur while the rule is still in the compressed history. Retaining a rule does not guarantee compliance: compacted runs that keep the rule violate more than twice as often as runs with the full history.

Yiwei Zha, Qingyu Meng, Herbert Bos et al.

arXiv cs.CR

Toward Deployable Hardware Roots of Trust for Edge AI: Software PUFs and Their Trade-offs

In briefSoftware PUFs as hardware roots of trust for existing edge AI devices

SummaryEdge AI devices with physical access risk exposing secret keys stored in non-volatile memory. Software physical unclonable functions (PUFs) derive unique responses from analog device characteristics through software-only interfaces, avoiding post-fabrication hardware changes. This paper surveys 37 software PUF works and compares them against on-device model protection requirements such as boot-time versus runtime key derivation and response latency. It analyzes trade-offs, outlines four key challenges for edge AI deployment, and highlights promising research directions.

Yilin Li, Farhad Merchant

★★★★☆ Notable
arXiv cs.CR

An Information Hierarchy of Privacy Filters and Odometers

In briefA study of how much information privacy filters and odometers need to work well.

SummaryThis paper studies how the information used by differential privacy filters and odometers limits their performance. It defines three information levels (spec, mechanism, and realisation) and classifies filters and odometers by the least informative level sufficient to determine their behaviour. The main results show strict and arbitrarily large performance gaps across this hierarchy, and that randomisation offers a separate resource that can also yield large utility gains.

WhyThe authors formalise a three-level information hierarchy and report arbitrarily large separations in filter and odometer performance across levels.

Sophie Taylor, Praneeth Vippathalla, Justin P. Coon

arXiv cs.CR

Systematic Derivation of Leakage in Massey Secret Sharing Schemes

In briefSystematically deriving information leakage in Massey secret sharing schemes.

SummaryThis paper studies leakage attacks on secret sharing schemes, where partial information about each share is used to recover the secret. Building on the Guruswami-Wootters construction, the authors derive new explicit linear exact repair schemes and analyze their algebraic properties. They also introduce a Gröbner-basis-based computational method for finding leakage functions across arbitrary linear codes. Applied to Reed-Solomon, generalized Reed-Muller, and Tamo-Barg codes, the method identifies several repair schemes not previously described in the literature.

Nadja Aoutouf (X, SURYCAT), Daniel Augot (X et al.

arXiv cs.CR

Cyber-JEV: Matched Contrastive Fine-Tuning of Language Models for Fast Source-Code Vulnerability Triage

In briefCyber-JEV: Contrastive fine-tuning with fix commits for fast vulnerability triage in source code

SummaryThe paper presents Cyber-JEV, a method that fine-tunes language models to give each source-code function a vulnerability score in a single pass, so security teams can rank functions for review. It builds comparison groups from fix commits, pairing each vulnerable function with its patched version and unchanged functions from the same file, and trains one model on classification and ranking. On a 7,270-function test benchmark, an ensemble of five fine-tuned Qwen3.5-4B models reaches an AUROC of 0.814, versus 0.743 for Jev 1.13.

Zhuyi Zhao, Shengjie Yuan, Shengyu Wang et al.

arXiv cs.CR · eess.SP

Leakage-Aware Encrypted Semantic Communication with Key-Conditioned Signal Perturbation

In briefEncrypted semantic communication with key-controlled signal perturbation and leakage-aware training

SummaryThis paper improves encrypted semantic communication by adding a key-conditioned signal-domain perturbation layer, called LAPI, and an InfoNCE-guided training rule that adds an adaptive leakage penalty to the fixed adversarial objective. Experiments on the Europarl corpus over AWGN and Rayleigh fading channels show that InfoNCE-guided training mainly suppresses the eavesdropper, lowering its BLEU to about 0.07 at high SNR. Adding LAPI further reduces the InfoNCE-estimated leakage by 5-9%, and the two mechanisms can be applied jointly.

Omar Kaaki, Maria Slim, Mariette Awad et al.

arXiv cs.CR

Evaluating autonomous self-healing against persistent cyber-attacks

In briefTesting self-healing defense against repeated cyber attacks

SummaryThis paper tests SH4CS, an immune-system-inspired self-healing cybersecurity software developed by TNO. The authors combine analytical and experimental evaluation against repeated exploits of web application vulnerabilities. Results show that SH4CS achieves effective cyber resilience in these scenarios. The paper notes that remaining challenges include balancing predictable resilient behaviour with adaptiveness to diverse threats and protected applications.

Bart Gijsen, Stefano Nieuwenhuizen, Lucien Yap et al.

arXiv cs.CR · cs.AI

Rethinking Neural Decompilation: Candidate Selection as the Hidden Bottleneck

In briefRethinking neural decompilation: candidate selection is the hidden bottleneck

SummaryThis paper studies why neural decompilers based on large language models still lag in accuracy on obfuscated binaries, focusing on how candidate code is generated and selected. The authors find that correct reconstructions are usually already among the model's sampled outputs, and they compare several ranking methods, with execution-guided selection performing best. After fine-tuning on the newly released ExeBench-Obfuscated dataset, pass@1 on obfuscated binaries rises to 88.8%.

Felix M\"achtle, Gautham Sriram, Manjil Neupane et al.

arXiv cs.IT · cs.CR · eess.SP

Movable Antenna-Assisted Secret Key Generation over Temporally Correlated Channels

In briefMovable-Antenna-Assisted Secret Key Generation over Temporally Correlated Channels

SummaryThis paper studies physical-layer key generation using movable antennas (MAs) over wireless channels whose multipath gains are temporally correlated, modeled by a first-order Gauss-Markov process. The authors derive a finite-horizon approximation error bound, a closed-form one-step conditional mutual information metric, and an alternating optimization algorithm that jointly tunes antenna positions and beamforming. Simulations show the MA scheme outperforms fixed antennas, with position optimization yielding about 51% higher rates and joint optimization a further 106% gain at high temporal correlation.

Zhiyu Huang, Chen Sun, Guyue Li et al.

arXiv cs.CR

ATrust: Adaptive Trust Boundary Expansion for Securing LLM Agents

In briefATrust: Adaptive Trust Boundary Expansion for Securing AI Agents

SummaryThis paper proposes ATrust, a defense for large language model agents against indirect prompt injection attacks. It starts from the user query as the root of trust and gradually admits task-essential external observations into the trust boundary during runtime. Evaluations on AgentDojo and AgentDyn report the strongest overall balance of security and utility among existing defenses.

Xu Zhang, Zhichao Lu

★★★★☆ Notable
arXiv cs.CR · cs.AI

The Customer Never Sees the Goal: Measuring and Detecting Vulnerability-Targeted Manipulation in LLM Assistants

In briefThe Customer Never Sees the Goal: Studies whether AI shopping assistants exploit customers' disclosed vulnerabilities to push a hidden operator goal, and whether this can be detected from the conversation.

SummaryCompanies can deploy LLM assistants on their websites with goals customers never see. The paper introduces GAP, which records the option a model recommends without any goal, then sets the other option as the operator's goal, collecting 619,600 labeled replies across 540 everyday scenarios for 15 models. Fourteen of the 15 models push the operator goal, and 12 of them use disclosed distress or financial strain to support it. Fine-tuned detectors reach 79% accuracy from the reply alone, while zero-shot LLM judges average at most 62%, and detection weakens for vulnerabilities not seen in training.

WhyThe authors propose detecting vulnerability-targeted manipulation from customer-AI conversations via goal-anchored probing, reporting tests on 15 models, 619,600 replies, and generalization to unseen

Bohan Jiang, Dawei Li, Yasin Silva et al.

arXiv cs.CR

Where Does MCP Security End? A Three-Tier Mitigation Mapping Framework for the OWASP MCP Top 10

In briefWhere MCP Security Ends: A Three-Tier Mapping of OWASP MCP Top 10 Risks

SummaryThis paper proposes a framework that maps the OWASP MCP Top 10 risks to three architectural tiers: server, gateway, and protocol. It uses a cascading decision tree of four questions to classify each vulnerability and assign a confidence level. The framework was validated against an enterprise Managed File Transfer MCP server written in Go. High-confidence server-tier controls performed as predicted, while low-confidence protocol-tier controls failed for architectural reasons beyond server implementation.

Christopher Krakauer, Andreas Schaad

arXiv cs.CR · cs.AI

StateFence: Task-State Protection Against Evidence-Chain Contamination in Blue-Team LLM Agents

In briefStateFence: A Defense Framework Protecting Blue-Team AI Agents from Poisoned Security Evidence

SummaryThis paper examines the risk that malicious instructions hidden in security telemetry, tickets, or retrieved content can spread through LLM agents used in Security Operations Centers. The authors propose StateFence, a framework that treats severity labels, incident narratives, response policies, and IOC sets as protected states. It maps attacks to explicit, stealth, multi-hop, and persistent categories and routes defenses according to the attacked state. The authors report that StateFence lowers attack success while preserving task utility.

Haowen Dai, Alejandro Guerra-Manzanares

arXiv math.NT · cs.CR · cs.IT

Explicit permutations of (ℤ/4ℤ)^m with uniformly bounded differential uniformity

In briefExplicit permutations of (Z/4Z)^m with uniformly bounded differential uniformity

SummaryThis paper constructs an explicit permutation G_c of (Z/4Z)^m whose differentials with nonzero input difference have probability at most 36/N, where N=q² and q=2^m. This is compared with the known lower bound of 2/√N for permutation polynomials over the same ring. The construction is a composition F_c∘J∘F_c built from polynomial layers and a digit exchange, and the bound does not depend on m.

Hiroki Fukui

★★★★☆ Notable
arXiv cs.SE · cs.CR

When Neither Side Confirms: Destructive Tool Approval Across MCP Servers and Hosts

In briefWhen Neither Side Confirms: A Study of Destructive Tool Approval in MCP Servers and Hosts

SummaryThis paper examines how AI agents calling destructive tools, such as deleting data or moving money, through the Model Context Protocol (MCP) are approved by humans. It measures both server-side confirmation and host-application approval steps by analyzing source code. The authors find that most destructive tools lack server-side confirmation and most hosts have no default approval step. They conclude that applications should configure approval themselves.

WhyThe authors measure missing human approval for destructive MCP tools from source code on both sides, and report an injected-deletion experiment across models.

Junwei Yao, Zike Yang, Zhijun Wang et al.

arXiv cs.CL · cs.CR

Ranked but Not Stopped: Detecting Prompt-Injection Hijacks from Typed Decision Models' Output Probabilities

In briefRanked but Not Stopped: Confidence Monitors Against Prompt-Injection Hijacks

SummaryThe paper studies language models used as classifiers, where injected text can shift the output label to one chosen by an attacker, a 'hijack'. The authors test a monitor that, without knowing the attacker's label, raises an alarm when the model's top probability is low, using AG News topic classification. Low confidence ranks hijacked answers above clean ones, but a threshold set for a 5% clean alarm rate misses most hijacks, especially when the injected text claims the target is certain.

Junwei Yao, Jianan Liu, Yongxi Zhou et al.

arXiv cs.CR · cs.AI · cs.CY

Networked Synthetic Social Engineering on the Web

In briefStudy of networked synthetic social engineering that misleads AI systems on the web

SummaryThis paper examines how synthetic social engineering, deliberate misleading influence aimed at redirecting AI recipients from authorized goals, spreads across networked services. The authors tested Qwen3-4B on two briefing tasks across 1,080 research units in their ASE-EC setup. Results show multiple dependent publishers did not increase unsupported verification, and correcting dependent reports reduced residual invalid decisions, though scope revalidation was needed for successful repairs.

Bryan C. Boots

arXiv cs.CR · cs.AI

Malware Clustering in the Wild: Taxonomy, Challenges, and Evaluation Metrics

In briefGrouping Malware Samples: A Survey of Methods, Challenges, and Evaluation Metrics

SummaryThis survey reviews clustering, a technique for grouping large collections of malware samples to reveal structure, behavior patterns, and evolution trends. It organizes prior malware clustering research into seven categories: centroid-based, hierarchical-based, density-based, distribution-based, mixed-type, fuzzy, and AI-driven approaches. The paper also summarizes publicly available malware datasets used in clustering studies and the feature representations derived from them, and outlines directions for future research.

Raguvir S, Bojing Li, Prajna Bhandary et al.

arXiv cs.OS · cs.CR · cs.DB

High-Throughput Private Information Retrieval with on-CPU Accelerators

In briefFast private database lookups using the built-in matrix units in CPUs

SummaryPrivate information retrieval (PIR) lets a client fetch a record without revealing which one, usually by scanning the whole database. This paper presents AltoPIR, the first PIR system to use on-CPU matrix accelerators such as Intel AMX, improving throughput through batching without extra discrete hardware. According to the paper, it reaches up to 50.1x the throughput of existing CPU-based solutions and can serve databases larger than a GPU's memory.

Gyuyeong Kim

★★★★☆ Notable
arXiv cs.AI · cs.CL · cs.CR

Accessed, never disclosed: Silent access to protected health information by medical artificial intelligence agents

In briefAccessed, never disclosed: silent access to protected health information by medical AI agents

SummaryThis paper examines whether medical AI agents access protected health information (PHI) tools even when a clinical task does not require patient identifiers. The authors embedded canaries in synthetic patient records and linked tool calls to canary exposure in final answers across five language models, four boundary levels, and seven attack frames. Three models invoked PHI tools unnecessarily, and the authors conclude that output-only evaluation cannot detect such silent access, so boundaries, pre-execution gates, and access-log audits are needed together.

WhyThe authors introduce canary-based tracking of silent PHI access, showing output-only evaluation misses it, with experiments across five models, boundary levels, and attack frames.

Jae Wang Lee, Abhirup Banerjee, Yeong Chan Lee

arXiv cs.CR

Detect, Repair and Audit: A Hierarchical Multi-Agent Defense Against Adversarial Attacks in Energy Forecasting

In briefDetecting, Repairing and Auditing Attacks on Energy Demand Forecasts with Multi-Agent Defenses

SummaryThis paper addresses the risk that time-series large language models used for electricity-demand forecasting can be distorted by compromised sensor inputs. It proposes a three-layer defense: a multi-agent reinforcement learning detector with signal repair at local control centers, and an LLM auditing agent with human-in-the-loop validation for Virtual Power Plants. The best detector configuration achieves an F1 score above 0.91 across all dataset-attack pairs, and signal repair reduces relative squared error by up to 83%, with detection and repair averaging 7.95 ms.

Zewei Shi, Ruoxi Sun, Minhui Xue et al.

arXiv cs.CR

Increasing the security of advanced metering infrastructure using dynamic defense methods

In briefUsing dynamic defense methods to strengthen the security of advanced metering infrastructure

SummaryThe paper notes that smart grids connected to the internet are constantly exposed to cyberattacks, and that the metering system, a critical part of them, could cause irreparable damage to a country and its industries if compromised. It proposes using dynamic "Applications that Participate in Their Own Defense" to protect such systems and infrastructure.

Mohsen Saffar, Hamid Reza Naji

arXiv cs.CR

A Matched Evaluation of QUBO Action Models and Defensive Remediation in Cyber Attack Graphs

In briefMatched evaluation of QUBO models for cyber attack graphs and defensive patching

SummaryThis paper examines how vulnerability-specific actions affect QUBO models for minimum-cost cyber attack paths and defensive remediation. Simulated annealing, steepest descent, and tabu search are compared against exact classical references on six synthetic topologies. A single labeled action per eligible transition preserved feasible paths, optimal costs, and QUBO size, while multiple exploit alternatives lowered optimal-path recovery and substantially enlarged the representation. The approach was also tested on a published 3CX attack graph with synthetic costs.

Kasymkhan Khubiev, Yaroslav Kholodov, Alexey S. Petrenko

arXiv cs.CR · cs.AI

Black-Box Adversarial Example Attacks on Machine Learning based Election Systems

In briefBlack-box attacks on machine learning ballot classifiers in elections

SummaryThis paper studies adversarial example attacks on machine learning models that classify ballots, assuming an attacker who cannot see the model's parameters. The authors implement and evaluate eleven black-box attacks across several norms and decision-, score-, and transfer-based threat models. They print and scan 20,000 adversarial examples to measure real-world performance, finding a larger physical-digital robustness gap than in white-box settings. The work also presents the first adversarial transferability study in the voting domain and tests adversarial training and barrier zones as defenses.

Subek Acharya, Syed Ayon, Khaleque Md Aashiq Kamal et al.

arXiv cs.CL · cs.CR · cs.SE Open resources

Decision Models as Policy Gates for Coding Agents: Explicit Policy Boundaries Improve Detection and Reduce False Alarms

In briefDecision models as runtime policy checks for coding agents, with explicit rule boundaries

SummaryThe paper evaluates 22 hosted decision models and two prompted general models as classifiers for a multi-rule policy engine that screens coding agent tool calls. On a synthetic dataset of 2,643 tool calls labeled against 28 rules, writing explicit boundaries as examples and counterexamples raised recall on all 23 models and reduced false positives on 21. The dataset, rule texts and harness are released.

James P. Beno

arXiv cs.CL · cs.CR

HaloGuard 2.0: An Open-Weights Constitutional Output Guard for Multilingual Response Safety

In briefHaloGuard 2.0: An Open-Weights Safety Filter for Checking Multilingual AI Responses

SummaryThis paper presents HaloGuard 2.0, an open-weight streaming guard that scores each response token as safe or unsafe in a single pass, so generation can be stopped once harm is confirmed. It reuses the constitution of HaloGuard 1.0 to organize a large response training corpus and adds a second training phase with counterfactual responses to correct a shortcut where the guard judged the prompt rather than the response. On six English response-safety benchmarks it reaches a macro F1 of 83.6, and a multilingual variant reaches 83.1 F1 on response labels across 17 languages.

Ashmiya Lenin, Navaneeth Sangameswaran, Preetham S

arXiv cs.CR · cs.LG · cs.NI

Bounded Retained History in a Proxy Flow Replay: A Mixed Predictive Pilot and an Allocation Study

In briefBounded History Retention in Flow Replay: A Predictive Pilot and Allocation Study

SummaryThe paper studies bounded retained history on a curated UNSW-NB15 flow mirror, first through a frozen predictive pilot and then an allocation study. In the pilot, adding retained relational features lowered reconnaissance recall and benign false-positive rate compared with the baseline, and AUROC was also lower, so no predictive advantage was shown. A follow-up allocation study found that source-balanced retention beat FIFO on an equal-source endpoint, while event-weighted ratios decreased, so the result is specific to that weighting objective. Reused data and proxy timing limit interpretation.

Juan S. Santillana

arXiv cs.CR · cs.AI

ZT-DAC: ML-Driven Dynamic Access Control Policy for Zero Trust in DER Networks

In briefZT-DAC: ML-Driven Dynamic Access Control for Zero Trust in Energy Networks

SummaryThis paper addresses the weakness of static role-based access control in distributed energy resource networks, where authenticated attackers can keep privileges and move laterally. It proposes ZT-DAC, a dynamic framework that uses two-stage verification, combining OPA-based RBAC with machine-learning-based ABAC for continuous trust score assessment. Experiments report 91.92% accuracy for the OPA decision layer and 93.27% for the ABAC layer.

Arun B. Chandrasekaran, Damilola Popoola, Souradeep Bhattacharya et al.

arXiv cs.CR

SANAI: Secure ECC Distributed Keyed Parity Embedded in Weights for Protecting Neural Networks against Bit-Flip Attacks

In briefSANAI: Keyed parity hidden in neural network weights to defend against bit-flip attacks

SummaryQuantized neural networks store their weights in dense memory, where bit flips from voltage scaling, aging, radiation, or attacks such as RowHammer can degrade model behavior. The paper proposes SANAI, a sensitivity-guided scheme that selects bit planes and embeds keyed parity within the weights with no extra parity storage. The authors report that across ten vision backbones, three quantization schemes, and ten language models, SANAI stays within about one percentage point of clean accuracy at bit-error rates up to 12%, about twice the limit of prior embedded-ECC approaches.

Habibur Rahaman, Daniel Lobo, Md Rezoan Ferdous et al.

arXiv cs.CR · cs.AI

Query-efficient scan-and-search watermark localization

In briefQuery-efficient method for locating hidden watermarks in AI-generated text

SummaryThis paper addresses how to pinpoint implicit watermarks that large language models embed in their outputs. It proposes an adaptive strategy that first covers the whole document broadly, then concentrates the detection budget on regions with stronger watermark evidence. Statistical signals from selected regions are converted into e-values and processed with a token-weighted e-BH procedure. The framework, named BELL, is reported to control the token-weighted false discovery rate without requiring independence across regions and to outperform competing methods across several LLMs, datasets, and watermarking schemes.

Liyuan Wang, Xinsong Ma, Ziye Ma

arXiv cs.CR

One String to Rule Them All: Measuring Consent Under the IAB Global Privacy Platform

In briefOne String to Rule Them All: Measuring Consent Under the IAB Global Privacy Platform

SummaryThis paper examines how the IAB Global Privacy Platform (GPP), a standard for sharing user consent across jurisdictions, transmits opt-out choices from publishers to third parties. The authors analyze data from four web crawls across four experimental settings. They study how widely the standard is adopted, whether opt-out signals propagate, and whether they affect advertiser behavior. The findings show implementation inconsistencies that cause consent signals to be lost and opt-out choices to go unrespected by advertisers.

Muhammad Abu Bakar Aziz, Christo Wilson

arXiv cs.CR · cs.NI

Accelerating QUIC Encryption in WebAssembly Using WASM-SIMD

In briefSpeeding up QUIC encryption in WebAssembly with SIMD instructions

SummaryThis paper examines the cryptographic cost of running the QUIC transport protocol inside WebAssembly (Wasm). The authors write explicit kernels using Wasm's 128-bit SIMD extension for AES and ChaCha20. On two hosts linked by 10-Gigabit Ethernet, these kernels raise receiver goodput over a non-SIMD baseline by 61.34% for AES-128-GCM and 31.55% for ChaCha20-Poly1305. The authors conclude that cryptographic acceleration is necessary but not sufficient, since memory allocation, runtime overhead and per-datagram UDP I/O still limit pure-Wasm transports.

Sota Yamawaki, Yasuo Okabe

★★★★☆ Notable
arXiv cs.CR · cs.AI

Beyond Prompt Injection: The Tool Update Gap in LLM Agent Security

In briefBeyond Prompt Injection: The Tool Update Gap in LLM Agent Security

SummaryThis paper examines how LLM agents that rely on external tools may keep trusting those tools after updates without re-verifying their safety, creating a supply-chain vulnerability. The authors introduce ETUDE, an attack that embeds malicious functionality into updates of initially benign tools while keeping their legitimate features, operating outside the LLM's context. Tested across three attack workloads and seven agentic frameworks, ETUDE achieved a 97.6% attack success rate with a 95.9% legitimate task completion rate, and existing defenses were found insufficient.

WhyThe authors identify the tool update gap and propose ETUDE, reporting attack success and task completion across seven agentic frameworks.

Shiyu Kan (1), Yue Qi (1), Yufei Han (2) et al.