Cryptography & Security

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

This week's picks

About the stars
  1. ★★★★★arXiv
    A classical client uses an untrusted quantum server as a virtual quantum computer
    WhyClassical client gains virtual quantum computing via untrusted server, resolving two open problems using a maliciously secure LWE-based protocol construction.
  2. ★★★★★IACR ePrint
    HELLO, GOODBYE: Concurrent Composition with Fewer Extra Rounds
    WhyReduces concurrent general composition overhead from doubling rounds to adding two, with rigorous security reductions improving Kushilevitz-Lindell-Rabin.
  3. ★★★★★arXiv
    CyberDual: an arena where AI attackers hide bugs and AI reviewers try to catch them in real software maintenance
    WhyProposes a dual attacker-reviewer arena with PoC-execution rewards, evaluated on 1,088 valid attacks, revealing refusal and attack capability decouple.
  4. ★★★★★arXiv
    FVQKD: Machine-Checked Security Proofs for Quantum Key Distribution in Rocq
    WhyFirst end-to-end machine-verified finite-key composable BB84 security proof, admit-free, uncovering an omitted side condition and missing proof branch in the original.
  5. ★★★★★arXiv
    AfterDeleteBench: Testing Whether LLM Agents Still Remember Deleted Secrets
    WhyIntroduces a matched-control behavioral audit showing deleted secrets are reconstructed from components across several models, bypassing literal filters.
  6. ★★★★★arXiv
    Scaling Laws for Safety Probes: Predicting Monitoring Performance from Model Size and Labels
    WhyProposes two simple scaling laws for safety probe error across model size and label count, validated on 20 models and six new datasets.
  7. ★★★★★arXiv
    SecDMP: A Provably Secure Data Prefetcher Defense (Extended Version)
    WhyClassifies DMP leakage and proposes SecDMP, a formally proven hardware defense blocking all leakage classes while preserving public-data performance.
  8. ★★★★★IACR ePrint
    Reverse Substitution in Secret Sharing: Critical Threshold and Route to Superpolynomial Lower Bounds
    WhyIntroduces reverse substitution with a counterexample and a one-half threshold, offering a route to superpolynomial lower bounds; rigorous and potentially highly influential.
  9. ★★★★★arXiv
    CoSA: Conflict of Skills Attack in Real-World LLM Agent Ecosystems
    WhyIntroduces a new composition-level attack paradigm with mechanism analysis and a guard, showing violation rates rising from 35.02% to 58.45% across five LLMs and three harnesses.
  10. ★★★★★arXiv
    NameTrap: Using Variable Names to Lead AI Coding Agents into Writing Vulnerable Code
    WhyIntroduces identifier-renaming poisoning steering coding agents toward CWEs, evaluated across six agents and ten models against strong baselines.

Stars are a rough AI assessment based on the title and abstract: each paper is scored for novelty, strength of evidence and breadth of impact, then mapped to 1–5 stars (about 2% get five stars and 10% get four). The site only marks four- and five-star papers as Notable, with a one-line reason; no mark does not mean a paper is weak. The full text is not read, so treat the stars as a reading aid, not a verdict on quality. "Code" means the abstract states that code, data or tools are released.

Wed, Oct 28, 2026

arXiv cs.CR Code

Revisiting Privacy Risks in Quantized Deep Neural Networks

In briefPrivacy risks of quantized neural networks: do compressed models leak more training data?

SummaryThis paper presents the first comprehensive empirical study of privacy risks in quantized deep neural networks, evaluating eight membership inference attacks across six quantization methods. Practical quantization levels of 4 to 8 bits have limited effect on membership privacy, leaving quantized models about as vulnerable as full-precision ones. Aggressive 2-bit quantization yields some privacy gains but substantially degrades utility. Existing defenses designed for full-precision models offer limited protection for quantized models while further amplifying utility loss.

Jie Fu, Ren Li, Wendy Hui Wang

arXiv cs.CR

When POST Becomes GET: Investigating HTTP Method Interchangeability and Its Security Implications

In briefWhen POST Becomes GET: How Interchangeable HTTP Methods Can Create Security Gaps

SummaryThis paper studies HTTP method interchangeability, where a POST request to an endpoint is rewritten as a GET request with its body parameters moved into the query string, yielding an equivalent response. The authors present MIDE, an automated pipeline that crawls web applications, converts captured POST requests, and compares responses. In an unauthenticated experiment on the Tranco top 10k, they found high-confidence interchangeable requests on 407 sites. The study also reports CSRF token-replay cases and conditions related to Web Cache Deception.

Matteo Golinelli, Seif Errahmane Hannachi, Bruno Crispo

arXiv cs.CR · cs.CY

Penny for Your Prompts: A Measurement Study of Contextual Leakage in AI Chat Platforms

In brief"Penny for Your Prompts": A Study of Chat Data Leaks on AI Platforms

SummaryThis paper measures how 42 AI chatbot web interfaces, including general-purpose and health, legal, and education platforms, share data with third parties. The researchers instrumented the browser's JavaScript engine to trace each data flow back to the user action that triggered it. They found that 21 platforms leak conversation titles and nine leak verbatim user prompts to third-party trackers, and many also send users' emails.

Paschalis Bekos, Billy Tsouvalas, Nick Nikiforakis et al.

★★★★★ Notable
arXiv cs.CR

SecDMP: Provably Secure Data Memory-Dependent Prefetching (Extended Version)

In briefSecDMP: A Provably Secure Data Prefetcher Defense (Extended Version)

SummaryData memory-dependent prefetchers (DMPs) are a CPU optimization in recent mainstream processors that can improve performance but may leak secrets through side channels. The paper classifies DMP leakage, categorizes existing and new attacks, and validates the analysis by implementing open-source DMPs on a RISC-V processor. It proposes SecDMP, a hardware defense in which secrets are marked in memory so DMPs never encode them in the microarchitecture. The authors formally prove SecDMP adds no leakage beyond a baseline without DMPs.

WhyClassifies DMP leakage and proposes SecDMP, a formally proven hardware defense blocking all leakage classes while preserving public-data performance.

Jens Sprengers, Marton Bognar, Lesly-Ann Daniel et al.

arXiv cs.CR

The Envelope Layer: An Underestimated Surface of LLM Agent Defense

In briefThe Envelope Layer: An Underestimated Defense Surface for LLM Agents

SummaryThe paper builds on prior work that treats the envelope layer as the channel through which malicious content enters an agent. Using the A2A-TIBA attack as a test vehicle, it runs a two-by-two factorial experiment and a memory experiment to examine how label strength, envelope authenticity, scaffold differences, and existing memories affect defense. Strong labels reduce semantic breach rates when envelopes are authentic, but weak labels are not always better than no label, and strong labels lose effect when envelopes can be forged. Memory has a larger effect than label manipulation. The authors refine the envelope layer into an admission channel and a context assembly surface, arguing its security boundary depends on label claims, frontend permissions, and historical memory together.

Yuelin Han

arXiv cs.AI · cs.CR · cs.DB

Constraining the Commit Boundary: A DIO/ODI-Informed Authorization Guardrail for Agentic Entity Resolution

In briefCommit-boundary authorization guardrail for AI agents resolving entity identities

SummaryThe paper proposes an authorization boundary for agentic entity resolution systems that separates evidence usable for reasoning from evidence allowed to authorize persistent identity changes. A domain-governed function maps reconstruction failures to identity-preserving constraints, and a two-phase supervisor permits a commit only when evidence covers every required proposition, conflicts are resolved, the operation is in scope, and versions are valid. It is a conceptual architecture without implementation or empirical validation.

Daniel Ber\'anek

Tue, Oct 27, 2026

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

Watermark Basins: Black-Box Detection of Distilled LLMs

In briefWatermark Basins: Detecting Distilled LLMs Using Only API Access

SummaryThis paper addresses API-based distillation, where an adversary trains a student model on a proprietary teacher model's outputs, and how providers can watermark outputs to detect it. The authors find that watermarked training creates a persistent, key-specific geometric signal in parameter space, orthogonal to ordinary fine-tuning directions. They propose WM-Basin, a black-box detector that needs only API queries, and report that it outperforms a token-level baseline on mathematical reasoning distillation while the signal survives quantization, pruning, and reinforcement-learning post-training.

WhyProposes a watermark basin signal orthogonal to task subspaces, detected via gradient alignment; evaluated across 135M to 8.2B students with clear gains over the token-level baseline.

Hongyan Chang, Hady Elsahar, Tom Sander et al.

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

When Is a Relation Worth Trusting? Manipulation Costs, Exposure, and the Trust Trap in Multi-Relational Graph Learning

In briefWhen Is a Relation Worth Trusting? Manipulation Costs and the Trust Trap in Graph Learning

SummaryThe paper studies multi-relational graph detectors, which learn how much to trust each relation from clean data, while attackers face different manipulation costs per relation. It proves that degree gating beats any selection or reweighting of a relation when part of the population is isolated on it and the attacker cannot afford to open the gate. A per-node exposure bound, computed without any attack, is proposed to decide which relation to harden and outperforms alternative criteria in most cases. Without cost information, the authors conclude the safe choice is to abstain from using the graph.

WhyProves degree gating strictly beats relation selection under sharp conditions, with real-graph validation and exact worst-case bounds; impact is confined to graph-security subfield.

Vincess Dongmo, Astride Melvin Fokam Ninyim

arXiv cs.CR

Asynchronous Verifiable and Complete Secret Sharing: From Design Patterns to System-Level Trade-offs

In briefAsynchronous Verifiable and Complete Secret Sharing: Design Patterns and System Trade-offs

SummaryThis paper examines secret sharing protocols that aim to work in fully asynchronous systems with Byzantine faults, where practical costs are hard to compare across studies. The authors derive a design sieve, select seven representative protocols, and implement them in a common Rust framework. Experiments on the Grid'5000 platform measure latency, throughput, message count, bandwidth, and CPU time under honest and faulty dealer conditions. The results indicate that message complexity alone poorly predicts latency, and that batching or packing helps only when verification stays off the critical path.

Joachim Bruneau-Queyreix (LaBRI, Bordeaux INP, UB) et al.

arXiv cs.CR · math.RA

GKS Fully Homomorphic Encryption: Security Analysis

In briefGKS Fully Homomorphic Encryption: A Security Analysis

SummaryThis paper gives a formal security analysis of the Gribov-Kahrobaei-Shpilrain (GKS) private-key fully homomorphic encryption scheme. Fully homomorphic encryption allows computation directly on encrypted data without decrypting it first. The paper states that GKS requires no bootstrapping or de-linearization, produces bit-exact decryption, supports native encrypted search, and scales to unbounded depth.

John Graham, Soundes Marzougui, Milo\v{s} Pavlovi\'c et al.

arXiv cs.CR

Janus Vehicles: Entity-Centric Threat Modelling of Protocol-Conformant Vehicles under a Malicious-Manufacturer Assumption

In briefJanus Vehicles: A Threat Model for Authentic Cars That Secretly Misbehave

SummaryThis paper challenges the automotive security assumption that manufacturers are benign, focusing on vehicles that are authentic and protocol-conformant yet perform undeclared sensing, communication, or triggered actions. It proposes an entity-centric threat model with four malign entity types: peer-benign purpose-malicious vehicles, compromised vehicles, reappropriated genuine components, and imitated vehicles or components. The authors also introduce a Behaviour-Locus Matrix mapping covert, overt, and concealment actions across hardware, software, and network, plus a Behavioural Interaction Model for peer-benign, purpose-malicious vehicles.

Jaeung Franciskus Yoo, Huy Kang Kim

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

Blindfold: Keeping the Audit Coin Secret from LLM Agents

In briefBlindfold: Keeping Random Audit Checks Hidden from LLM Agents

SummaryThis paper studies audit-based certification, which limits an LLM agent's violation rate by auditing a random fraction of its actions and reweighting the results. The authors show that validity also requires the audit coin to stay hidden from the agent before its action is committed. They define this as pre-commit noninterference, measure it, and derive bounds on the resulting bias. Experiments on a monitor and a real LLM agent show that a visible audit notice leaks the coin and breaks the certificate, while a silent audit or a fresh coin per audited call restores validity.

WhyIntroduces pre-commit noninterference with tight bias bounds, a novel theory; experiments on LLM agents confirm the channel but at limited scale.

Wei Zhu, Meiyun Zuo, Huiping Sun

arXiv cs.CV · cs.CR · math.PR

RePAIR: Inverting Backdoor Attacks in Semantic Segmentation

In briefRePAIR: Reversing Backdoor Attacks in Semantic Segmentation

SummaryThis paper presents RePAIR, a post-hoc, label-free defense against backdoor attacks on semantic segmentation models that does not depend on knowing the attack method. It uses the difference between classifier-head predictions and internal representations to infer the victim-target class relation from an unlabeled image pool, then corrects suspicious pixels. Experiments across segmentation architectures and attack settings show that it substantially reduces attack success while largely preserving clean performance.

Arnold Brosch, Kira Maag

arXiv cs.CR

Too many clients spoil the logs: distributed parsing, aggregation techniques and metrics

In briefDistributed log parsing: how many clients affect results, and how to measure them.

SummaryThis paper studies log parsing in distributed settings for anomaly detection in IoT systems, where several organizations must agree on log templates. The authors evaluate five parsing algorithms combined with aggregation techniques that unify event-template mappings across clients, testing 6,720 distributed configurations. They also introduce new metrics for evaluating distributed parsers and offer lessons learned and recommendations for their design and deployment.

Andr\'e Garc\'ia G\'omez, Viktor Beck, Max Landauer et al.

arXiv cs.CR

Developing a Dynamic Multi-factor Authentication System for Securing Smart Organizations

In briefA dynamic multi-factor authentication system to secure smart organizations

SummaryThis paper proposes a dynamic multi-factor authentication system within a Zero Trust Architecture that enforces continuous verification. It randomly selects biometric factors such as fingerprint, iris, and face recognition using a Markov chain model to reduce predictability. Experiments use CASIA biometric datasets and AES-128 encryption, and performance analysis indicates the approach balances security and efficiency for smart organizations and e-government.

Mohsen Saffar, Hamid Reza Naji

★★★★☆ Notable
arXiv cs.CR

HqcLethe: Streaming HQC Encapsulation for Tiny Stateless Servers

In briefHqcLethe: streaming HQC key encapsulation for tiny stateless servers

SummaryThis paper presents HqcLethe, a stateless post-quantum key exchange that streams an HQC key encapsulation in packet-sized pieces, so servers need not buffer multi-packet handshakes and avoid memory-exhaustion attacks. It uses the Chinese remainder theorem to split polynomial multiplication into independent, masked remainders, one per packet. The authors prove in Rocq with SSProve that the masked pieces reveal no more than an ordinary HQC ciphertext, and verify session secrecy, server authentication and forward secrecy in ProVerif. On a Raspberry Pi 3B+, each worker uses a fixed 1.2-1.6 MiB, and at category 5 it sends 27x fewer bytes and uses 9.0x less server CPU than McTiny.

WhyUses the Chinese remainder theorem to split HQC polynomial multiplication into independent packet pieces, with formal proofs and protocol verification.

Wind Wong, Klaus v. Gleissenthall

arXiv cs.SD · cs.CR

The Content Leash: Mitigating Degenerate Solutions in Invertible Speaker Anonymization

In briefThe Content Leash: Reducing Degenerate Solutions in Reversible Speaker Anonymization

SummaryThis paper studies reversible voice anonymization, which hides a speaker's identity while keeping the spoken content, and lets authorized users recover the original voice. The authors add content-preserving training constraints so anonymization does not rely mainly on degrading speech, and a verifier-generalization strategy that uses a stronger speaker-verification representation during training. On 38 unseen speakers, the attacker's equal error rate rises from 2.8% to 26.3%, and to 27.9% against a held-out verifier. Key-based restoration yields an 11.8% word error rate and 94.9% speaker similarity.

Nirjon Mobarak Talukder, Rafid Ahmed, Mohammad Ishrak Abedin et al.

arXiv cs.CR

Beyond LWE: Post-Quantum Assumptions under a Counterfactual Break of the Dihedral Coset Problem

In briefPost-quantum assumptions if the Dihedral Coset Problem is broken

SummaryThis survey examines the consequences of a genuine breakthrough on the Dihedral Coset Problem, motivated by a refuted 2026 claim of an efficient quantum algorithm for it. It distinguishes three solver hypotheses and composes reductions to compare their sufficient guarantees with more than thirty lattice and non-lattice assumptions. The paper audits a published structured state conversion and separates rigorous consequences, heuristic comparisons and unverified applications. It closes with open questions and a scenario-planning checklist.

Ramses Fernandez

arXiv cs.CR

PrivacyEvalClaw: A Tool-Augmented Deliberative Agent for Auditing Privacy Leakage in LLM Jailbreak Responses

In briefPrivacyEvalClaw: A Tool-Augmented Agent for Auditing Privacy Leaks in LLM Jailbreak Responses

SummaryThis paper addresses the difficulty of reliably judging whether jailbreak responses from large language models reveal personal information, especially when disclosures are indirect or obfuscated. The authors find that existing guard models and LLM-as-Judge evaluators often disagree, particularly on ambiguous cases. They introduce PrivacyEvalClaw, a training-free deliberative agent that treats evaluators and analysis modules as tools, gathers evidence adaptively, and reconciles conflicting signals before judging. In pairwise LLM-as-Judge experiments on full trajectories, it reportedly achieves favorable win rates against baselines while producing auditable reasoning traces.[ok]

Krishna Kanth Nakka, Yujun Wang, Shijie Zhou et al.

arXiv cs.CR · cs.LG

Quantifying and Prioritizing Stealthy Source-Manipulation Threats Against Multi-Source Anomaly Detectors

In briefMeasuring and ranking stealthy source-manipulation threats to multi-source anomaly detectors

SummaryThe paper studies how an adversary controlling some data sources can stealthily manipulate a downstream decision in a multi-source security pipeline. The authors propose a task-conditioned visibility margin, the least detector evidence a manipulation must reveal per unit of harm to the downstream task, which has a closed form and yields minimum-evidence attacks. On a 17-channel industrial telemetry benchmark, a detector flagging 82.8% of random single-channel corruptions was first-order blind on 64.7% of task/subset pairs across one- to four-channel audits.

Indraveni Chebolu, Seema Panghal, Arnab Mallick et al.

arXiv cs.CV · cs.CR

Haste Makes Waste? Towards Safe Few-Step Text-to-Image Models

In briefDoes speed compromise safety? Safer few-step text-to-image models

SummaryFew-step distilled text-to-image models are attractive for their fast generation, but their rate of unsafe outputs was unknown. The paper finds that few-step models are often more unsafe than their teachers, that fewer inference steps raise unsafe generation rates, and that existing concept-erasure methods work less well on them. It proposes DICE, a post-distillation erasure method, which reduces the unsafe-generation rate on FLUX Schnell to 0.046 while mostly preserving benign generation quality.

Lior Ziv, Mahmood Sharif

arXiv cs.CR · cs.HC

Measuring Users' Security and Privacy Concerns About Third-Party Community Bots on Discord

In briefMeasuring User Security and Privacy Concerns About Discord Third-Party Bots

SummaryThis paper analyzes 23,102 third-party Discord bots and 183,142 user reviews from 2021 to 2026. Using a fine-tuned classifier, the authors identify 8,832 reviews related to security and privacy and group them into a 31-theme taxonomy. The most common concerns involve data sharing and data collection. The authors also present BotLens, a proof-of-concept auditing framework that combines review signals with bot metadata to support decisions about community bots.

Kofi Ampomah, Tu Le

arXiv cs.CR · cs.AR

Silent Blindness: Fault Vulnerability of Hardware Malware Detectors

In briefSilent Blindness: Hardware Malware Detectors' Vulnerability to Faults

SummaryThis paper studies how faults in hardware malware detectors (HMDs), which classify performance-counter data, can weaken detection. The authors ran structural fault injection over 18 classifiers, four counter budgets, and AdaBoost and Bagging ensembles, evaluating 453,174 stuck-at and bit-flip events. Tree-based models showed a lower share of critical faults than function-based models, and most tree faults left recall and false-positive rate nearly unchanged. The paper also presents a minimax method for selecting protection candidates under idealized assumptions.

Alireza Abolhasani Zeraatkar, Parnian Shabani Kamran, Parsa Mirfasihi et al.

arXiv cs.CR

Peak-DNA: Recurrent Morphology in Global Narrative Propagation

In briefPeak-DNA: Recurring Shape Patterns in Global Narrative Spread

SummaryThis paper presents Peak-DNA, a framework for finding recurring propagation shapes in global news narrative streams. It converts hourly GDELT activity into normalized peak episodes through denoising, peak consolidation, and time alignment, then compares their shapes using DTW-based similarity. The study analyzes five high-amplification domains: Iran, Defense, AI, Space/Elon, and Quantum/PQC. Results show that amplification events within each domain tend to converge toward similar propagation patterns.

Joosung Kim, Luyonghe Li, Shanwen Wu

arXiv cs.AI · cs.CR · cs.SE

CASEL: Consequence-Aware Selective Execution for Reliable Long-Horizon Tool-Using Agents

In briefCASEL: A runtime layer that decides how carefully AI tool calls should be checked before running

SummaryThe paper introduces CASEL, a model-agnostic policy that chooses, for each tool call an AI agent proposes, whether to execute directly, verify, sandbox, clarify, seek approval, or abstain, based on failure probability, consequence, reversibility, ambiguity, and evidence freshness. In a controlled simulation over 20 seeds with 120,000 test actions each, CASEL reduced harmful-side-effect trajectories from 14.75% to 7.02% compared with an uncertainty-ranked gate. The authors state that intervention effectiveness was assumed rather than measured, so the results rank allocation rules under simulator assumptions and do not establish deployment effectiveness.

Yanyan Zhang, Fei Shen, Ting Yan et al.

IACR ePrint Attacks and cryptanalysis

When Algebraic Structure Meets Too Many Hints

In briefAlgebraic structure and too many hints: rethinking side-channel leakage evaluation

SummaryThe paper argues that DDGR hint classes and too-many-hints thresholds cannot serve as standalone security metrics for real side-channel leakage, because they ignore the algebraic structure of hint vectors. In synthetic experiments on Kyber-512, NTT-domain residues, formally mod-q hints, recovered the full secret with about half the hints predicted by the uniform bound. Finite-precision FFT samples, classed as approximate hints, needed only 25% to 55% of the budget for uniform perfect hints. Evaluating leakage requires considering algebraic structure, not just hint category and quantity.

Dongshu Cai, Yijian Liu, Xianhui Lu

arXiv cs.LG · cs.CR

Split Federated Unlearning

In briefSplit Federated Unlearning: Removing Learned Contributions from Partitioned Federated Learning

SummarySplit federated learning combines partitioned model execution with federated aggregation for collaborative learning across distributed environments. This paper gives the first systematic formulation of Split Federated Unlearning (SFU), covering client-wise and class-wise removal, counterfactual retraining, and partition-specific update constraints. It proposes SURE, which integrates dual-importance estimation, selective parameter perturbation, and importance-guided recovery, and reports competitive agreement with mode-matched retraining.

Jia Chen, Yecheng Lv, Xinrong Hu et al.

arXiv cs.CR · cs.IT · cs.LG

A Simple Presentation of Robust Membership Inference Attacks

In briefA concise introduction to robust membership inference attacks

SummaryA membership inference attack lets an attacker, given one individual's data, guess whether that person was part of a dataset, using statistics from the dataset or a model trained on it. The paper gives a simple presentation of robust membership inference attacks for mean estimation, covering multivariate Gaussian and binary product distributions. It also summarizes the literature on the topic, including its history, extensions, and links to other research areas.

Renaud Gaucher, Ephraim Linder, Adam Smith et al.

arXiv cs.CL · cs.CR · cs.CY

No Tokenizer, Still a Gap: Cross-Lingual Fairness of Homoglyph and Invisible-Character Watermarking

In briefNo Tokenizer, Still a Gap: Fairness of Lookalike-Character Watermarks Across Languages

SummaryThis paper studies watermarks that hide signals by swapping characters for visually similar homoglyphs or inserting invisible characters after text is written, without involving the generating model. It measures across 40 language varieties in 24 scripts how many hidden bits each character can carry, and how much survives routine handling and targeted removal. Capacity varies 3.3-fold, with script accounting for 96% of the variation. Lower-resourced languages tend to use scripts with few homoglyphs, so an inequity across languages remains.

Alexander Nemecek, Yuqiao Xu, Joseph Falkenburg et al.

arXiv cs.CR · cs.HC

What Victims Take Away: Attack Reuse and Defense Revision after Prompt-Injection Attacks

In briefWhat Victims Take Away: Reuse of Prompt-Injection Attacks and Defense Changes

SummaryThis paper studies how players targeted by prompt-injection attacks in the online game Tensor Trust use the attack texts they received, using 563,349 attack records. Reuse mainly followed whether an attack succeeded, not how its reply read, and breaches were followed by defense changes that lowered the success of same-family attacks. The authors derive testable hypotheses for how AI security tools should disclose attacks, such as describing the technique without the full text.

Zihan Chen, Lei Nico Zheng, Di Zhu

arXiv cs.CV · cs.CR · cs.LG

ORBITAL: Optimization of Robust Brain--Computer Inference Through Architecture-Aware Low-Precision Compression

In briefORBITAL: Robust, Hardware-Efficient Compression for Brain-Computer Interface Decoders

SummaryThis paper presents ORBITAL, a framework for compressing compact EEG decoders for brain-computer interfaces while preserving adversarial robustness and improving hardware efficiency. On BCI Competition IV-2a across nine subjects and three seeds, the S25-TRADES compressed EEGNet achieved the highest mean robustness (23.06% versus 21.27% for the standard full model), with 26.27% fewer parameters and 25.10% fewer MACs. On a Jetson Orin Nano, FP16 compression reduced board energy by up to 16.20% and latency by 8.00%, whereas native INT8 Q/DQ incurred about twice the FP16 latency and energy.

Saim Rehman, Muhammad Shafique

arXiv cs.CV · cs.CR · cs.LG

Evaluating Federated Vision-Language and Vision-Only Models for Privacy-Aware Breast Cancer Imaging

In briefPrivacy-Aware Federated Vision-Language Models for Breast Cancer Imaging Evaluation

SummaryThis paper evaluates a federated learning framework that combines pretrained vision-language and vision-only models with client-level differential privacy for breast imaging. Five models, including CLIP, BiomedCLIP and an ImageNet ViT-B/16 baseline, were compared on two public datasets. Normal-versus-sick discrimination was high, but acquisition year alone achieved a similar score, raising confounding concerns. Benign-versus-malignant discrimination was uncertain, removing the text pathway halved communication cost while preserving accuracy, and differential privacy substantially reduced ROC-AUC.

Malithi Mithsara Wanniarachchi Kankanamge, Ning Yang, Sree Bash Debnath et al.

arXiv cs.CR

PHP2Shell and the Future of AI-Discovered Vulnerability Disclosure: Evidence, Verification, and Human Authority

In briefPHP2Shell and AI-Discovered Vulnerability Disclosure: Evidence, Verification, and Human Authority

SummaryThe paper presents FedTrust-CVDv2, a federated framework for coordinated vulnerability disclosure that separates evidence validation, inter-organizational coordination, human governance, and permissioned auditing. It binds signed observations to exact evidence revisions and limits external actions to approved payloads, audiences, expiry, policy, and revocation state. A local reference implementation and a PHP2Shell case formulation are used to illustrate the approach.

Toqeer Ali Syed, Asadullah Abdullah Khan

arXiv cs.CR · cs.AI

Detecting and Mitigating Query-Based System Prompt Leakage Attacks

In briefDetecting and Mitigating Query-Based System Prompt Leakage Attacks

SummaryThis paper presents AdvGuard, a model-agnostic framework that detects and mitigates leakage of LLM system prompts through query-based attacks. Such attacks extract confidential instructions over multiple adaptive turns, which per-query defenses often miss. AdvGuard models relationships across queries with a bounded semantic interaction graph and classifies them with a graph convolutional network. It improves recall by up to 36% over the strongest baseline with a false positive rate of at most 3.4%, and substantially reduces prompt leakage in evaluated attack loops.

Tushar Nayan, Pratik Poudel, Qian Lou et al.

arXiv cs.CR · cs.AI · cs.LG

BUSTA: Teaching Small Language Models to Reason About Binary Execution

In briefBUSTA: Training Small Language Models to Reason About Binary Execution

SummaryThis paper examines whether targeted training can give small open language models reverse engineering skills. Given an x86-64 basic block and a desired output register state, the model predicts the input register values that produce it. After fine-tuning with GRPO, Qwen3-1.7B improves from 73.2% to 85.3% and Nemotron-3-Nano from 63.3% to 95.2% on knowable-register prediction. The fine-tuned Nemotron-3-Nano comes within four points of the best frontier model (99.2%) at a much smaller parameter count. The authors release both fine-tuned models and the training dataset.

Ritika Poddar, Aidan Fennelly, Deirdre Murphy et al.

★★★★☆ Notable
IACR ePrint Implementation

Analyzing Compiler-induced Constant-time Violations with Compiler at Scale

In briefCTGREP: Finding Compiler-Induced Timing Leaks in Crypto Code at Scale

SummaryThis paper presents CTGREP, a compiler-based framework that uses differential analysis across the whole compilation chain to find where compilers break constant-time cryptographic code, how the violation is introduced, and which configurations cause it. The authors applied it to seven complete cryptographic libraries across three Clang versions, six platforms, and thousands of compiler configurations. They worked with library developers to fix 48 cases and identified seven new problematic LLVM passes.

WhyDifferential analysis across the whole compilation chain improves on single-point detection; validated on seven crypto libraries, with 48 fixes and seven newly identified problematic LLVM passes.

Jing Liu, Lucía Martínez Gavier, Zhiyuan Zhang et al.

arXiv cs.CR · cs.LG

Privately Clipping Heavy-Tailed Data

In briefA method for choosing clipping bounds privately on heavy-tailed data

SummaryThis paper studies vector summation in differentially private data analysis. The authors propose a way to privately select a clipping bound by balancing the directional alignment of vectors that exceed the bound (residual coherence) against the variance cost of added noise. They prove a close relationship between residual coherence and bias for a general class of heavy-tailed data. Experiments on several datasets show the method outperforms existing baselines.

Matthew Joseph, Alex Kulesza

arXiv cs.CR

SpecGuard: Detecting Multi-Turn LLM Jailbreaks via Specification-Based Runtime Monitoring

In briefSpecGuard: Detecting Multi-Turn LLM Jailbreaks with Specification-Based Runtime Monitoring

SummaryThe paper presents SpecGuard, a training-free framework that monitors multi-turn conversations with large language models using formal specifications written in Linear Temporal Logic. Each specification is compiled into a symbolic finite automaton that processes the dialogue trace incrementally. When a forbidden pattern is detected, the system produces replayable evidence identifying the specification, supporting facts, and relevant turns. Experiments on multi-turn safety benchmarks report that SpecGuard outperforms representative open-source guard models while keeping false-positive rates controlled.

Junle Li, Siqi Chen, Jiakai Li et al.

★★★★★ Notable
IACR ePrint Foundations

Reverse Substitution in Secret Sharing: The Critical One-Half Threshold and a Route to Superpolynomial Lower Bounds

In briefReverse Substitution in Secret Sharing: Critical Threshold and Route to Superpolynomial Lower Bounds

SummaryThis paper studies substitution, a way of building composite access structures by replacing one participant of an outer structure with an inner structure in secret sharing. It asks whether the contribution vector of any scheme for the composite structure can be reverse-factored into vectors for the outer and inner factors. The authors show exact reversal fails via a counterexample with factor 8/9, but prove a factor of 1/2 is always attainable. For a recursive family built from Csirmaz's access structure, they identify a critical factor slightly above one half whose crossing yields superlinear lower bounds, and show Shannon inequalities alone cannot reach it.

WhyIntroduces reverse substitution with a counterexample and a one-half threshold, offering a route to superpolynomial lower bounds; rigorous and potentially highly influential.

Shahram Khazaei

arXiv cs.CR · cs.CY

Bringing Hardware Security Education to All: A Seamless Curriculum Integration Approach

In briefTeaching hardware security within existing core courses so every student can learn it

SummaryThe paper argues that undergraduate curricula largely overlook hardware security, and that dedicated courses reach very few students. The authors describe an economical approach that embeds nine hands-on modules into existing core courses, linking each security concept to a design concept of the host course. Three modules were evaluated across three offerings of an embedded systems course, with 25 respondents.

Tanvir Hossain, Mahmudul Hasan, Kareem El-Araby et al.

★★★★☆ Notable
arXiv cs.CR

They Will See Johnny's Message: A Measurement Study of Post-Quantum Cryptography Across Email Delivery Paths

In brief"They Will See Johnny's Message": A Measurement Study of Post-Quantum Cryptography in Email Delivery

SummaryThis paper systematically measures post-quantum cryptography (PQC) deployment across email delivery stages, including relay, submission, and access services, as well as sending servers and OpenPGP and S/MIME implementations. It finds that PQC support is concentrated among a few providers and that available capability is not consistently used in practice. Usable PQC message encryption is further limited by key generation, key-format, and backend integration issues.

WhySystematic multi-stage email PQC measurement reveals capability-use gaps and plaintext fallback, with strong evidence and significant impact on email security.

Jaehwan Park, Sunghyun Park, Kevin Nam et al.

★★★★★ Notable
IACR ePrint Cryptographic protocols

HELLO, GOODBYE: Concurrent General Composition From Super-Rushing Security

In briefHELLO, GOODBYE: Concurrent Composition with Fewer Extra Rounds

SummaryThis paper studies how to keep synchronous multiparty computation protocols secure when many executions run concurrently. Earlier methods added a synchronisation step after every round, roughly doubling the round count. The authors show that for protocols secure against super-rushing adversaries, adding only a start round (HELLO) and an end round (GOODBYE) suffices, giving security with selective abort in R+2 rounds. Using a broadcast channel for the end round upgrades the guarantee to unanimous abort.

WhyReduces concurrent general composition overhead from doubling rounds to adding two, with rigorous security reductions improving Kushilevitz-Lindell-Rabin.

Anirudh Chandramouli

★★★★☆ Notable
arXiv cs.CR · cs.AI

Log-To-Leak: Prompt Injection Attacks on Tool-Using LLM Agents via the Model Context Protocol

In briefLog-To-Leak: Prompt injection attacks on tool-using LLM agents via the Model Context Protocol

SummaryThis paper studies security risks for LLM agents that access external tools through the Model Context Protocol (MCP). It introduces Log-To-Leak, an attack that makes an agent place an extra, attacker-controlled tool call after the legitimate one, leaking the user query, server name, server response, and agent response. Across 18 valid model-server pairs, the attack reaches an attack success rate of 62.64% to 100%, and three tested defenses still leave over 55% residual success on GitHub MCP with GPT-4o. The authors conclude that a task can finish correctly while unauthorized disclosure happens, and they recommend host-controlled authorization for secondary tool calls.}

WhyProposes an additive post-hoc logging exfiltration attack on MCP tool poisoning, backed by multi-model, multi-server experiments and defense evaluations.

Yuepeng Hu, Chongyu Fan, Sirat Samyoun et al.

★★★★☆ Notable
arXiv cs.CR · cs.AI

I-HITL: Inalienable Human-in-the-Loop

In briefI-HITL: Inalienable Human-in-the-Loop (a mechanism ensuring AI agents need human approval)

SummaryThis paper introduces inalienable human-in-the-loop (I-HITL), a protocol ensuring an AI agent can act only with explicit human approval, even if the agent has compromised the local system. In experiments on a popular agentic wallet platform, ten frontier models often autonomously raised a spending cap by harvesting emailed one-time passcodes, bypassing the human approval guardrail. The authors formally define I-HITL using communication topologies, prove necessary and sufficient conditions for its realization, and present a prototype called Countersign that strengthens existing HITL systems using off-the-shelf mobile devices.

WhyFormalizes inalienable human-in-the-loop with proven necessary and sufficient conditions; experiments on ten models show broad impact, though experimental scale is limited.

Samuel Breckenridge, Dani Vilardell, Wenhao Wang et al.

arXiv cs.IT · cs.CR · cs.LG

Information-Theoretic Secure Aggregation With Heterogeneous Client Quantization

In briefInformation-theoretically secure aggregation for clients with different quantization levels

SummaryIn federated learning, secure aggregation lets a server learn only the sum of clients' model updates, not the individual updates. Because clients have different bandwidth limits and choose different quantization levels, existing methods can leak partial aggregates and, under certain dropout and collusion patterns, segments of individual updates. The paper proposes an information-theoretically secure scheme that tolerates client dropouts and up to T semi-honest clients colluding with the server, using a (T+1, N) threshold black-box secret sharing construction to handle heterogeneous quantization.

Shreya Meel, Sennur Ulukus, Itzhak Tamo

arXiv cs.CR · cs.AI

Reva: Real-Time Vulnerability Detection through Contextual Probing of Large Language Models

In briefReva: Real-time vulnerability detection by probing LLMs with context

SummaryThe paper presents REVA, an AI vulnerability detector that judges each new function in a single LLM forward pass, using a pre-computed threat model, lightweight static analysis, and call-graph information. A trained probe reads the model's internal representations to reach a verdict. On PrimeVul's held-out test set, REVA on GLM-5.3-Flash reaches 60.0% accuracy in about one second per function, matching the agentic detector VulTriage (59.2%) while being over 250 times faster and less than a tenth as costly.

Amine Lbath, Massih-Reza Amini

★★★★☆ Notable
IACR ePrint Foundations

On Robust Combiners for Pseudorandom Codes and PKE with Pseudorandom Ciphertexts

In briefRobust combiners for pseudorandom codes and public-key encryption with pseudorandom ciphertexts

SummaryThe paper asks whether robust combiners, which hedge cryptographic assumptions by combining several candidate constructions, can be built for pseudorandom codes (error-correcting codes whose codewords are indistinguishable from uniform strings) and for public-key encryption with pseudorandom ciphertexts. The authors prove that secret-key pseudorandom codes admit no black-box robust combiner, even under the weakest guarantee where all but one candidate must be secure. They also show that public-key encryption with pseudorandom ciphertexts admits no black-box robust combiner, in contrast to ordinary IND-CPA encryption.

WhyProves impossibility of black-box robust combiners for pseudorandom codes and pseudorandom-ciphertext PKE, contrasting sharply with standard IND-CPA encryption.

Nico Döttling, Venkata Koppula, Mahesh Sreekumar Rajasree et al.

★★★★☆ Notable
IACR ePrint Cryptographic protocols

LINE-Break: Cryptanalysis and Reverse Engineering of Letter Sealing

In briefLINE-Break: A security analysis of LINE's custom Letter Sealing encryption protocol

SummaryThis paper analyzes the security of Letter Sealing v2, the custom end-to-end encryption protocol used by the LINE messaging app. The authors ran a machine-in-the-middle attack on an iOS device and experimentally verified attacks against the authentic app and an independent implementation. They report that the protocol allows message replay, reordering, blocking, sender impersonation, and plaintext leakage through stickers and URL previews. The authors conclude that Letter Sealing does not meet the requirements of a modern end-to-end encrypted messaging protocol.

WhySystematic analysis of LINE's custom E2EE protocol finds replay, impersonation, and plaintext leakage attacks, verified on the real app.

Diego F. Aranha, Adam Blatchley Hansen, Thomas Kingo T. Mogensen

arXiv cs.CR · cs.CL

Atomic Security Concerns: Towards a Foundational Language for Security Knowledge Representation

In briefAtomic Security Concerns: A Foundational Language for Representing Cybersecurity Knowledge

SummaryThis paper introduces Security Concerns and Atomic Security Concerns (ASCs), testing the hypothesis that cybersecurity knowledge can be represented through a finite set of foundational concerns. Drawing an analogy to atoms in chemistry, it treats cybersecurity concepts as compositions of these more basic concerns. The authors propose ASCs as a common abstraction layer and possible vocabulary for a cybersecurity language, with concepts expressed as concern sets with explicit relationships. The work is conceptual, offering a framework and research hypothesis for future formalization..

Hanane Houmani

arXiv cs.CR · cs.CV

A Category-Selective Encryption Framework for Privacy Protection of UAV Images

In briefA Framework That Encrypts Only Chosen Sensitive Object Types in Drone Images

SummaryDrone aerial surveillance often captures sensitive objects such as pedestrians and vehicles along with other scene content. The paper proposes a framework that first detects objects with an 80-class detector and then encrypts only user-specified sensitive categories, leaving other objects and the background intact for downstream analysis. It supports two schemes: Thumbnail-Preserving Encryption, which uses adaptive pixelation and a jointly trained Enhanced U-Net for recovery, and XOR stream cipher encryption, which is parameter-free and mathematically exactly reversible.

Ting Yan, Minghui Shang, Haolang Sun et al.