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Monday 28 September

Cryptography and Security

Raising the Bar for Chinese Adolescent LLM Safety: A Culturally-Grounded, Fine-Grained Benchmark

Safety risks in conversations with adolescents are not always explicit. A request may appear harmless unless a model considers the user's age, circumstances, and earlier turns. Existing Chinese safety benchmarks mainly target general users and give limited attention to adolescent safety. Single-turn tests also miss risks that emerge over several turns. QH-Bench is a Chinese-language benchmark for adolescent content safety, with scenarios grounded in Chinese social and cultural settings. The single-turn track contains 715 test items organized into 10 risk domains, 50 subdomains, and 143 fine-grained risk scenarios. The multi-turn track contains 100 four-turn trajectories in a balanced 10-by-10 design that combines the same ten domains with ten cross-turn mechanisms. Both tracks use the same five-level safety-helpfulness scale and automatic judge, with track-specific criteria. Evaluation of 13 open-weight models identifies offline-contact scenarios as a shared weakness. Every model receives negative scores on more than half of the items involving offline meetings with online contacts, unfamiliar groups, and adults. This includes InternLM2.5-20B, the single-turn leader; negative scores indicate responses that partially or clearly facilitate risk. GLM-4-32B, the multi-turn leader, receives negative scores on 60% of complete trajectories in which users build relationships before invoking loyalty or confidentiality. These findings identify two priorities for the evaluated models: handling adolescent offline-contact risks and maintaining safety boundaries under relational pressure. Leading aggregate scores do not establish that these specific weaknesses have been resolved.
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All authors Jinxiang Wang, Yifan Liu, Jing Tan, Xiangyu Zhao, Xin Yao, Xuetao Wei

Cryptography and Security · Cross-listed from cs.LG

Distillation Defenses Easily Break After Reinforcement Learning

Distillation attacks copy the reasoning capabilities of closed-source large language models, allowing bad actors to replicate state-of-the-art performance at low cost. Attackers systematically collect a large volume of frontier model reasoning traces and then train (i.e., "distill") their own models on these traces. Existing defenses against distillation attacks are typically evaluated immediately after distillation, implicitly assuming attackers do not train their models any further. In this paper, we argue that a more realistic threat model includes further training with reinforcement learning after distillation. A misspecified threat model can give a false sense of security – some defenses that seem effective after distillation can be broken after subsequent reinforcement learning. Practically, reinforcement learning lowers the bar for a distillation attack to be effective. We show that simple attacks can steal reasoning capabilities from existing closed-source language models using data easily obtainable from current APIs, yielding reasoning improvements equivalent to more sophisticated attacks that extract the full hidden traces. Results indicate that any distillation defense that leaks sufficient information to reconstruct approximate reasoning traces is likely ineffective. We conclude by discussing broader implications and batch-level distillation defenses which could be more effective.
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All authors Shidan Javaheri, Alexander Panfilov, Oliver Britton, Yarin Gal, Yonatan Gideoni

Cryptography and Security · Cross-listed from cs.CE

Tracekit: Tamper-Evident Intent-Reasoning-Action Auditing for Autonomous Coding Agents

Autonomous coding agents read untrusted files, run shell commands and spawn sub-agents with little supervision, yet their record is usually an editable log. We present Tracekit, an open-source, dependency-free system that captures three channels for every agent session: what the human asked (intent), what the model said of its reasoning (self-report), and what it actually executed (actions). These are written to a hash-chained, externally anchorable ledger and cross-checked. Tracekit hooks into Claude Code's lifecycle events, reconstructs multi-agent hierarchies, gates tool calls with a pre-execution policy, accepts events from other agents via an SDK or HTTP API, and renders a live observer that re-verifies the ledger in the browser. We evaluate Tracekit in five experiments. (1) Across 1,600 random mutations, the chain detects every edit, deletion, reordering, forged insertion and torn write; tail truncation and full re-chaining are caught only by anchors, with detection falling to 0.47 at an anchoring interval of 300 records, matching a closed-form model. (2) A hook costs 23.9 ms median, flat up to 100,000 ledger records, and the chain stays correct under 16 concurrent writers. (3) A regular-expression gate blocks only 18 of 44 harmful tool calls (41%) while wrongly blocking 3 of 40 benign ones; trivial rewrites evade it. (4) In 14 real Claude Code runs, the agent never acted on four planted indirect prompt injections and disclosed each. The provider withheld the text of all 27 thinking blocks, so self-report was limited to visible prose. (5) With seeded-fault splicing, a new method that inserts concealed misaligned steps into real traces, over 63 traces and 126 reviewer calls, rule flags caught 40/49 (82%) of faulted traces and an independent LLM reviewer caught 98/98 (100%), with a false-positive rate of 1/14 on unmodified traces. We release the system, harness and all traces.
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Cryptography and Security · Cross-listed from quant-ph

Succinct Arguments for QMA from Collapsing Hash Functions

We prove the existence of succinct arguments for QMA, assuming only the existence of collapsing hash functions. This is the first scheme that relies only on unstructured “Minicrypt” assumptions, which are not known to imply public-key encryption. Our main technical contribution is a quantum-succinct claw-state generation protocol that allows us to bootstrap a small number of quantum correlations into an arbitrarily large number of claw-state correlations, using classical communication only. This improves upon the work of [Zhang, STOC 2021], having better round complexity, a proof in the standard model, and being overall much simpler. This yields a quantum-succinct blind delegation of quantum computation protocol from one-way functions, which we plug into the communication-compression compiler of [Bartusek, Liu, and Malavolta, EUROCRYPT 2026] to obtain succinct arguments for QMA.
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Cryptography and Security

SEABench: Benchmarking Endogenous Misalignment In Self-Evolving Agents

Self-evolving LLM agents have gained prominence for their ability to improve after deployment by modifying their harness, including their controller instructions, memory management protocols, and reusable tools and skills, in response to user and environment feedback. However, locally useful updates may persist into later tasks where they produce unsafe behavior, even without direct adversarial influence. To study this risk, we introduce SEABench, a benchmark for studying endogenous misalignment arising from agent self-evolution, with 48 longitudinal task sequences that span multiple evolution surfaces, task domains, and harm types in a rich personal-assistant environment. To account for the stochasticity inherent in agentic operations, we provide an adaptive trajectory discovery pipeline that probes for failures while preserving original task intent and supports causal attribution through paired non-evolving agents and attribution scores. Our evaluation across multiple recent LLMs, evolution surfaces, and harm types reveals that self-evolution indeed increases task completion rates but often at the cost of safety failures that are absent for paired non-evolving baseline agents. We also show that qualitatively different safety behaviors emerge across evolution surfaces and harm types. Further, we show that this divergence in safety behavior is reflected in agents' chain-of-thought reasoning, which yields an effective monitoring strategy that can mitigate unsafe behavior with a low false positive rate.
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All authors Saswat Das, Parvati Viswanathan, Daniel Donnelly, Chang Huang, Sahar Abdelnabi, Ferdinando Fioretto

Cryptography and Security · Cross-listed from cs.AI

Share-Borne AI Virus: Memory-Hopping Attacks Across LLM Agents

Large language models are increasingly deployed as stateful assistants that retain information across interactions and use tools to read, modify, and create persistent artifacts. As these artifacts are shared between users, they form an indirect communication channel between otherwise independent assistants. We study a failure mode in which this channel enables self-propagating attacks. We introduce artifact-mediated propagation, where adversarial content introduced through an artifact (e.g. a report), is stored in an assistant's persistent memory, reproduced in a subsequently created artifact, and acquired by another assistant that later reads it. We evaluate this process in temporal human-agent universes that model artifact exchange between independently operated assistants over time, measuring whether an attack survives successive hand-offs, how many hops it reaches, and how broadly it spreads. We find that attacks can propagate across multiple independent assistants and persist over extended interaction sequences. In larger simulated environments, even GPT-5.6 Luna exhibits substantial spread, reaching 60-80% of agents with propagation chains extending to eight hops. These results show that persistent artifacts can act as durable carriers of adversarial state, allowing attacks to outlive individual interactions and spread across isolated assistants.
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All authors Sidharth Pulipaka, Ansh Sharma, Stanislau Hlebik, Leonidas Raghav, Vyas Raina, Ivaxi Sheth, Mario Fritz

Cryptography and Security

The Compiler May Read It, the Agent May Not: Keeping Part of a Research Code Away from a Coding Agent

The compiler must read modules a physics-based solver cannot build without; the coding agent must not read that intellectual property. The harness, the software around the model that executes its tool calls, does not ship that rule. We classified fifteen read routes against a container, permission rules and a sandbox. None of the three can tell which program is reading.
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Cryptography and Security

INTCC: A Framework for Interactive Confidential Computing

Confidential computing leverages Trusted Execution Environments (TEEs) to ensure the confidentiality and integrity of data in use. However, TEEs rely on remote attestation to guarantee the integrity of their initial memory state. This model is fundamentally at odds with interactive development workflows. In scenarios like LLM fine-tuning and exploratory data analysis, data processors need human-in-the-loop capabilities, including dynamic code injection, intermediate state inspection, and hyperparameter tuning, all of which inherently violate the static, one-time integrity guarantees of traditional remote attestation. To reconcile this tension, we propose the interactive confidential computing paradigm, a system architecture enabling untrusted data processors to execute dynamic, non-deterministic operations within TEEs without compromising data confidentiality. Driven by the insight that inherently unmeasurable human interaction must be excluded from the Trusted Computing Base (TCB), we logically partition the TEE into an interactive controller and a verifiable runtime. To realize this paradigm, we present INTCC, a framework featuring three key mechanisms: (1) a proxy-based dispatch system to preserve the native development experience; (2) a fine-grained information flow control mechanism based on a security lattice to prevent data leakage; and (3) a privacy-preserving verifiable execution mechanism to guarantee the runtime compliance of dynamic workflows. We implement INTCC on AMD SEV-SNP using Confidential Containers and evaluate it across diverse real-world workloads. Our experiments demonstrate that INTCC effectively balances security and interactivity, incurring a practical overhead of less than 5% for LLM fine-tuning and under 17% for data analysis relative to baseline execution.
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Cryptography and Security

Detecting False Data Injection and Unstable Operation in Smart Grid via System-Aware Graph Boundary Learning

Cyber-physical power systems increasingly rely on data-driven tools to detect instability and support reliable grid operation. However, reliable stability prediction is difficult when unstable operating configurations are rare, sensitive, or unavailable during model development, since collecting such data safely and at scale is often impractical. At the same time, False Data Injection (FDI) attacks can manipulate reported system parameters to trigger false instability alarms or conceal unsafe operation, and such threats in Decentral Smart Grid Control (DSGC) systems remain largely unexplored. These challenges are rarely addressed jointly, leaving a gap between stability prediction and attack detection that this work aims to close. In this paper, we introduce StarGNN, a graph learning framework that learns the stable operating region exclusively from clean stable configurations and uses a single abnormality score to flag reported configurations that should not be trusted as evidence of safe operation, covering both genuine instability and unseen FDI manipulations. Each configuration is represented as a producer-consumer star graph and processed by a role aware graph neural network, with physics constrained pseudo-negatives generated by perturbing reaction time and price response parameters standing in for the unavailable unstable and attack data. A single threshold, calibrated only on held-out stable data, is used without task or attack specific adjustment. Evaluated on nine unseen FDI scenarios, StarGNN detects between 0.780 and 0.973 of attacks on stable configurations and retains a post attack instability recall between 0.972 and 0.999 on unstable ones, with 0.899 recall against a stronger adaptive attacker, showing that stable-only boundary learning can support both stability prediction and attack detection without access to genuine unstable labels or attack samples during training.
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All authors Emad Efatinasab, Denis Donadel, Mirco Rampazzo, Chuadhry Mujeeb Ahmed

Cryptography and Security

Beyond Scalar Probes: Exploiting Vector-Valued Outputs in ReLU Networks For Signature Extraction

We revisit cryptanalytic extraction of ReLU networks from a geometric and algebraic perspective. Rather than restricting attention to a single output component, we study the full vector-valued behavior across adjacent linear regions. This leads to a rank-one characterization of Jacobian differences that recovers the usual row-signature information while also revealing complementary column-side information. Our experiments show how this additional structure can be used in ex- traction and improves numerical estimation under different numerical- precision regimes (float64, float32 and float16). We extend the analysis beyond the high-precision and output-rounding settings commonly con- sidered in the literature towards the low-precision settings encountered in many practical settings.
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All authors Gorka Abad, Claude Carlet, Ermes Franch, Stjepan Picek, Vincent Rijmen

Cryptography and Security

LLM-Assisted Automatic Security Proofs for Cryptographic Protocols: How Far Are We?

Large language models (LLMs) have shown strong potential for assisting software and security analysis tasks, yet their effectiveness in cryptographic symbolic protocol verification remains insufficiently understood. In this paper, we conduct the first systematic evaluation of the capability of state-of-the-art LLMs in cryptographic symbolic protocol verification. To quantify this capability, we propose CRoST (Coverage Rate of Solve Tree), a proof-based metric derived from the verifier's proof skeleton that measures the similarity between generated lemmas and reference lemmas. We then establish the rationale of CRoST through both theoretical analysis and empirical validation. The evaluation results show that state-of-the-art models achieve 38.82% coverage on average, with 14.4% of generated lemmas exceeding 80% coverage, indicating that LLMs can already generate useful lemmas to a certain extent. However, they still exhibit non-trivial failure modes on complex multi-phase protocols, show diminishing returns under naive scaling, and incur substantial verification overhead. These findings clarify the practical potential and limitations of LLMs for protocol verification and motivate future work on complex real-world protocols.
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All authors Tianjian Liu, Shicheng Feng, Jin'ao Shang, Xiaoting Lyu, Bin Wang, Zonghua Zhang, Lei Xue, Wei Wang

Cryptography and Security

Indistinguishability of Sum of Permutations: A Fourier Analytic Route to Classical and Quantum Security

We study classical and quantum indistinguishability of sums of independent random permutations and related transformations from permutations to functions. Let $G$ be a finite abelian group of order $N$, and let $\pi^k_+(x)=\pi_1(x)+\cdots+\pi_k(x)$ for $k\geq2$ independent uniform random permutations of $G$. We give a unified Fourier analytic treatment in which the construction is represented by its probability density and a distinguisher by its acceptance function, with the classical and quantum query models imposing different restrictions on the Fourier support of the latter. Classically, we obtain the bound $O_k(q/N^{k-1/2})$ for every $q<N$, and refine it below the birthday threshold to $O_k(q^2/N^k)$. In the quantum model, a simulation argument gives $O_k(N^{-(k-3/2)})$ for $q\leq(N-1)/2$, while Fourier interpolation gives concrete finite bounds up to $q\leq4N/15$ and the query-dependent bounds $O\left(\min\left\{N^{-1/2},q^3/N^2 + 1/N\right\}\right)$ and $O_k\left(\min\left\{q^3/N^k,N^{-(k-3/2)}\right\}\right)$, for $k=2$ and $k \geq 3$, respectively, throughout $1\leq q\leq(N-1)/2$. For $q = 1$, the first bound sharpens to $O(N^{-2})$. Over $G=\mathbb F_2^n$, a one-query Fourier attack matches the order of our one-query bound, while an $N/2$-query parity attack with advantage $1/2$ shows that our bounds reach the constant-advantage query threshold. We further study two variants of sum of permutations over binary vector spaces. First, we allow arbitrary surjective linear postprocessing, which includes truncation, and obtain classical and quantum bounds that retain the output-size dependence. Second, we analyse Dinur's variable-output single-permutation construction, $\mathsf{LXoP}$, for every fixed output width, and derive its classical and quantum security bounds; for one- and two-block outputs, we give concrete quantum security bounds.
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All authors Ritam Bhaumik, Chun Guo, Xiaoning Guo, Ashwin Jha

Cryptography and Security

AI-Based Vulnerability Assessment Capability and Cyber Attack Graph Analysis

Cyber threats targeting mission-critical infrastructure are becoming more sophisticated while the barrier to launching attacks continues to fall. Traditional point solutions like antivirus and firewalls are reactive and fail to address the combinatorial complexity of modern attack surfaces. This paper presents an investigation combining two complementary methodologies: Lockheed Martin's Vortex/Crow framework, which applies multi-agent reinforcement learning (MARL) over industry-standard cyber knowledge graph to identify and prioritize attack vectors and TTPs (tactics, techniques, and procedures); and Aalto's probabilistic attack graph model that combines network topology and its vulnerabilities to compute system-level risk metrics. The 2015 Ukraine Power Grid cyberattack serves as a well-documented validation scenario. Applied independently to the same operational technology (OT) network topology, both methodologies converge on the same attack vectors and exploit sequences as those documented in the incident record, thus providing mutual cross-validation. Attack graph analyses using node-level elimination experiments identify industrial control systems (ICS) as the most critical enablers of attack propagation, representing high-priority targets for defensive hardening. Comparison of CVSS (v2.0) and IronMiner vulnerability scoring yields in general consistent results, with IronMiner providing more actionable differentiation at network periphery nodes. The layered methodology of baseline assessment and node-level elimination proves to be scalable to large enterprise networks, thus offering defenders a structured, AI-enabled path to prioritize mitigation under realistic time and resource constraints.
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All authors Joni Herttuainen, Kirsi Hellsten, Vesa Kuikka, Ambrose Kam, Arlanda Johnson, David Welsh, Kimmo K. Kaski

Cryptography and Security

"Nothing to See Here”: Unintended Disclosure through Revision Traces of LLM Deliverables

Large language model (LLM) assistants increasingly help users draft content for third-party recipients. During private drafting, the user or the model may introduce an item and later remove or replace it. The model may remove the item from the intended content but reveal it again when stating the edit. We call such statements revision traces. For example, after a user removes the password before sharing a configuration file, the model may delete it but leave a comment saying, "Removed the password 'No****4!' as requested." A third-party recipient who sees only the delivered file can therefore recover the withdrawn password from the comment. In an in-the-wild analysis of three public conversation corpora, we identify 26,753 revision requests, of which 2,363 (8.8%) leave revision traces. We study them in greater depth under controlled conditions by introducing RevLeakBench, a benchmark of 100 tasks across five scenarios with a conversation track and an agent track. We measure trace occurrence, withdrawn-item recovery, trace position, and required-content retention. Across six models, about half of the deliverables in both tracks state the edit after a revocation, and a reader that sees only the deliverable can recover the withdrawn item from about 13% of them. Telling the model that its entire reply will be forwarded to the recipient still leaves revision traces in 36.4% of the deliverables. We compare prompt defenses and a delivery boundary, and propose an output-side filter that sharply reduces recovery with little loss of required content. We believe our work can benefit efforts to understand and mitigate unintended disclosure in LLM interactions.
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Cryptography and Security · Cross-listed from cs.OS

Planarian: Managing Agent State with Statepoints

LLM agents solve complex tasks by iteratively changing files, invoking local tools, and interacting with remote services, which modifies state across their local environment and remote services. Today, agents and users must manage these changes explicitly, whether reverting exploratory actions or recovering from erroneous ones. Doing so safely requires coordinated actions, yet current agent harnesses lack unified abstractions and mechanisms for managing local and remote state consistently and efficiently. We describe Planarian, an agent runtime with state management that enables agents and users to recover from erroneous actions and explore alternative executions over consistent local and remote environment state. Planarian introduces the abstraction of agent statepoints, which are consistent, restorable point-in-time versions of the environment state. Planarian exposes three state-management primitives to agents and users: (i) snapshot creates a new statepoint spanning local and remote state without requiring external services to support checkpoints: it relies on efficient incremental process and file system snapshotting to capture local sandboxed state, and transparently records compensating actions to undo remote state changes; (ii) rollback restores the environment to a previous statepoint by reverting to a prior local checkpoint and replaying compensating actions for remote state changes; and (iii) fork creates multiple isolated branches from a statepoint, enabling the agent to explore alternatives in parallel. We show that Planarian enables agents to undo mistakes and explore alternatives in parallel, improving task quality by up to 15x, and allows users to recover from erroneous actions with only 3% overhead.
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All authors Jinnan Guo, Hao Mark Chen, Kapil Vaswani, Andrew Paverd, Peter Pietzuch

Cryptography and Security · Cross-listed from cs.NI

Hybrid QKD-PQC Network Emulation through Automated and Scalable Cloud-Native Orchestration

The ongoing transition toward quantum-safe networking has motivated the development of hybrid network architectures integrating Quantum Key Distribution (QKD) and Post-Quantum Cryptography (PQC). However, the experimental evaluation of hybrid QKD-PQC network architectures remains constrained by the high cost and limited accessibility of quantum hardware, as well as by the limited support for hybrid QKD-PQC networks in existing emulation platforms. Quditto is an open-source emulation platform originally designed for QKD networks that enables cost-effective and reproducible experimentation without requiring dedicated physical quantum infrastructure. Building on this foundation, this work presents Quditto as a hybrid QKD-PQC network emulation platform featuring automated and scalable cloud-native orchestration. The proposed platform introduces four principal contributions: a cloud-native orchestrator enabling fully automated infrastructure deployment across cloud and multi-cluster environments; an optimized provisioning workflow enabling large-scale quantum-safe network emulation; native integration of post-quantum nodes enabling unified emulation of hybrid QKD-PQC networks; and a secure key management module providing persistent and access-controlled storage of cryptographic material. Experimental validation demonstrates sublinear orchestration-time scaling with network size and successful end-to-end hybrid QKD-PQC key establishment on a representative spine-leaf deployment, thereby enabling the systematic evaluation of quantum-safe networking mechanisms in large-scale heterogeneous network environments.
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All authors Iván Melijosa, Javier Pérez, Borja Nogales, Iván Vidal, Francisco Valera

Cryptography and Security · Cross-listed from quant-ph

Zero Knowledge Proofs in Quantum Networks

Zero-knowledge proofs (ZKPs) enable the verification of a statement without revealing any information beyond its validity and constitute a fundamental primitive in cryptography and information theory. However, existing constructions rely on computational assumptions and are predominantly confined to bipartite settings, leaving their information-theoretic realization in bipartite or network scenarios largely unexplored. Here we develop a framework for zero-knowledge verification based on the indistinguishability of quantum states under operational constraints. Exploiting the fundamental limitations imposed by local operations, we show that a verifier is inherently restricted from extracting information about the underlying state while retaining the ability to verify correctness. We construct explicit protocols for multiparty quantum networks that achieve information-theoretic security, ensuring that no subset of collaborating parties can gain knowledge beyond the validity of the statement, independent of their joint computational power.
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All authors Tuhin Paul, Srijani Das, Manasi Patra, Ramij Rahaman

Cryptography and Security

Sustained Participation as a Security Resource: The Bounded Participation Channel

Can sustained, per-identity participation be engineered into a security resource? Most anti-Sybil defenses price identity creation rather than identity survival. Once admitted, an adversary may sustain many identities without paying a recurring cost. We introduce the Bounded Participation Channel (BPC), a formal primitive for repeatedly verifying participation window by window. BPC issues fresh, identity-bound challenges under a strict deadline and enforces four structural properties: identity binding, freshness, real-time response, and bounded per-channel throughput. Together, these yield a provable cost theorem: sustaining $s$ identities over $T$ windows requires $C(s,T) \geq sT/\tau_h$ participation channel-windows. The guarantee is solver-agnostic: a channel may be operated by a human, an AI system, or a hybrid. We give a hash-based construction with publicly verifiable participation proofs, characterize four admissible challenge families, and evaluate two against GPT-4o, Gemini 2.5 Flash, and Claude Sonnet 4.5 across 600 trials. Despite near-perfect accuracy (97–100%) on the perceptual tasks, the evaluated automated channels remain throughput-bounded under the tested deployment conditions. The results illustrate a key distinction: solvability does not imply unlimited throughput. By requiring participation to be re-earned by every identity in every time window, BPC turns sustained participation into a measurable security resource with a linear structural cost floor, independent of whether the participation is supplied by humans, AI systems, or hybrids.
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All authors Homayoun Maleki, Nekane Sainz, Jon Legarda, Igor Santos-Grueiro

Cryptography and Security

Continuous Assurance of Agentic Security Auditors for Software Delivery Decision Gates

Large language model (LLM)-based repository auditors are increasingly deployed as security controls within continuous integration (CI) pipelines, where their findings admit, block, or delay software changes. As Agentic Software Development Life Cycle (SDLC) Security Controls, their non-deterministic behaviour changes the evidence, while organisational risk appetite and jurisdictional or data-sovereignty policy change its interpretation. Point-in-time audits therefore cannot maintain current assurance for merge decisions. We propose the Policy-Evidence-Execution Separation Pattern, implemented by the Trustworthy AI Posture (TAIP) Assurance Engine and operated as Continuous Control Posture Assurance (CCPA). By separating policy from stable execution and binding admitted evidence to a versioned Posture Tree, the same assurance logic operates across models, environments, and policy profiles. We evaluate the approach using unmodified RepoAudit on a fixed Python Null Pointer Dereference benchmark. The retained evidence repository contains 80 RepoAudit executions across two OpenAI model configurations, gpt-4o-mini and gpt-4.1. TAIP recomputes assurance posture after policy, evidence, and model-context changes and is evaluated across increasing numbers of independent Decision Gateway contexts. The maximum observed policy-to-posture latency was 1.1 ms across three policy-class cycles in one execution. At 1,000 independent assurance contexts, full policy-triggered recomputation with one worker recorded a maximum aggregate refresh of 1.62 s, below the predeclared 5 s Decision Gateway budget. These single-host measurements concern assurance over retained evidence and exclude RepoAudit execution and provider inference.
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All authors Guy Lupo, Nguyen Hung Nguyen, Viet Vo, M.A.P. Chamikara, Guangdong Bai, Nazatul Haque Sultan, Alsharif Abuadbba

Cryptography and Security

Implementing Data Diodes Using Commodity Hardware and Open Source Software

One-way network devices, known as data diodes, are used to defend against sophisticated cyberattacks. Partly due to their high cost, data diodes are mostly deployed in nuclear power plants and within the government for handling classified information. Although commercially available data diodes are expensive, a data diode's hardware can assembled from commodity fiber-optic network equipment. However, specialized software is needed to send data through a data diode reliably: the receiving program cannot request retransmission of dropped packets, so packet loss must be minimized and mitigated. First, we developed a minimal program to measure packet loss. We found that most packet loss was caused by the receiving program processing incoming packets too slowly, and that packet loss often occurs in clusters. Also, we discovered ways to minimize packet loss on Linux and macOS without using superuser privileges. Next, we tested three existing open source programs for one-way data transfers: netcat, UDPcast, and lidi. Although these programs were unreliable in their default configurations, we identified reliable configurations for UDPcast and lidi. Finally, we incorporated our findings into pydiode, our cross-platform program for reliable one-way data transfers.
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Cryptography and Security

Poster: Towards ProofWeave: A Privacy-Minimised, Integrity-Anchored Evidence Plane for Continuous Agentic Assurance

Agentic AI systems increasingly act via tools, memory, delegation, and external services. Existing observability and provenance mechanisms can reconstruct events post hoc, but they rarely show, at the time of the record, whether each policy-relevant action was checked by the intended control before execution. This leaves a trust-observability gap for continuous monitoring, detection, and response: later assurance may rest on evidence that is incomplete, privacy-leaking, mutable, or detached from the policy context that governed the event. What's missing in the literature is contemporaneous, policy-bound evidence that the intended control was evaluated under the policy in force at the time. We introduce ProofWeave, a record-time chain-of-evidence concept for agentic AI assurance. At each policy-relevant action boundary, ProofWeave generates a privacy-minimised and integrity-anchored evidence transaction that binds (i) agent intent or action, (ii) control response, and (iii) a policy-at-time snapshot. Each transaction is committed to an append-only ledger and materialised into a derived proof graph. A bounded Weaver Agent translates policy intent into proof obligations, while deterministic validators check evidence completeness, privacy minimisation, policy binding, and integrity. In the minimal scenario, an agent attempts to transmit a secret to an unapproved external sink. The audit compares a logs-only correlation baseline with ProofWeave across verdict latency, join ambiguity, privacy exposure, tamper detection, and resistance to graph-only proof injection. ProofWeave reduces candidate bindings per verdict from up to `10,201` to one, validation operations from up to `10,201` to approximately `26`, and assurance evidence storage from `0.79`M̃iB to `0.15`M̃iB per project.
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All authors Guy Lupo, Nguyen Hung Nguyen, Viet Vo, Chamikara M.A.P., Guangdong Bai

Cryptography and Security · Cross-listed from cs.LG

TANGO: Watermarking Masked Diffusion Language Models in Token Pairs

Masked-diffusion language models fill in masked positions in parallel and in no fixed order. Most practical text watermarks assume left-to-right generation. They key each token to the tokens before it, and in a diffusion model those tokens may still be masked. A fixed green list needs no such context, but it favors the same tokens at every position, so these tokens appear more often in watermarked text. An attacker who compares token frequencies in watermarked and unwatermarked text can recover the list and forge text that the provider's own detector accepts. We present TANGO, a watermark for masked-diffusion language models that keys each new token to a nearby token that is already unmasked. A secret key splits the vocabulary into color classes, and TANGO biases the new token toward a color determined by the key and the nearby token's color. The watermark is therefore embedded in pairs of tokens. Because the favored color changes from position to position, token frequencies stay much closer to those of unwatermarked text than under a fixed green list. Detection needs only the text and the key, and it does not assume any unmasking order. On two masked-diffusion models, TANGO detects nearly all unedited watermarked texts and most edited ones, and frequency attacks that forge the fixed green list fail against it.
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All authors Kasra Arabi, Nir Weinberger, Micah Goldblum, Niv Cohen

Cryptography and Security

OT-PCA: New Key-Recovery Plaintext-Checking Oracle Based Side-Channel Attacks on HQC with Offline Templates

In this paper, we introduce OT-PCA, a novel approach for conducting Plaintext-Checking (PC) oracle based side-channel attacks, specifically designed for Hamming Quasi-Cyclic (HQC). By calling the publicly accessible HQC decoder, we build offline templates that enable efficient extraction of soft information for hundreds of secret positions with just a single PC oracle call. Our method addresses critical challenges in optimizing key-related information extraction, including maximizing decryption output entropy and ensuring error pattern independence, through the use of genetic-style algorithms. Extensive simulations demonstrate that our new attack method significantly reduces the required number of oracle calls, achieving a 2.4-fold decrease for hqc-128 and even greater reductions for hqc-192 and hqc-256 compared to current state-of-the-art methods. Notably, the attack shows strong resilience against inaccuracy in the PC oracle-when the oracle accuracy decreases to 95%, the reduction factor in oracle call requirements increases to 7.6 for hqc-128. Lastly, a real-world evaluation conducted using power analysis on a platform with an ARM Cortex-M4 microcontroller validates the practical applicability and effectiveness of our approach.
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Cryptography and Security

Trajectory-Level Security Debt in LLM Coding Agents

LLM coding agents can traverse hundreds of intermediate code states before submitting a solution. Evaluating only the final artifact leaves the evolution of security findings unmeasured. We introduce the Security Debt Line Integral (SDLI), which accumulates static-analysis risk when an agent reaches a new best test pass ratio. We instantiate it with four static application security testing (SAST) tools and study artifacts from 830 passing SWE-bench runs, 712 ProgramBench final workspaces, and 13 public MirrorCode trajectories. The two large populations use the final-state special case of SDLI. Two-tool Common Weakness Enumeration (CWE) class agreement occurs in 3.9% of SWE-bench runs and 26.2% of the 80 ProgramBench runs passing at least 90% of official tests. These are scanner findings, not validated vulnerability rates. Excluding three advisory-heavy classes reduces the latter rate to 6.2%. Same-task runs differ in their measured scores, while one reconstructed ProgramBench run exposes persistent findings from its first implementation write. A repair case study reduces the scanner signal while preserving tested behavior, but also reveals sensitivity to equivalent API rewrites. SDLI offers a way to study progress and security findings together. Its value for steering agents and confirming exploitable vulnerabilities remains to be established.
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All authors Prateek Kumar Rajput, Abdoul Kader Kabore, Yewei Song, Melissa Tessa, Tailia Malloy, Jacques Klein, Tegawendé F. Bissyandé

Cryptography and Security · Cross-listed from cs.DC

Analyzing Solana's Blocks and Transactions

Solana is one of the most popular blockchains, and is arguably the most widely used blockchain for smart contracts, also known as dApps. Understanding the types of smart contracts that are being executed by Solana and their interplay is therefore highly beneficial both for designers of modern blockchains and developers of smart contracts. To that end, in this paper we analyze a million recent Solana blocks. We report statistics about the size of blocks (number of transactions per block), execution time units for individual transactions and fees, and invoked Solana programs. Further, based on the declared readset and writeset of each transaction, as mandated by Solana, we analyze the conflicts and corresponding conflict graphs arising within each block. These latter statistics are important to understand the potential for parallelism in the network, which is one of the main claimed benefits of Solana. The data and code are available in open source.
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Cryptography and Security

LENS: The Sum Is Worse Than the Parts for Set-Level Poisoning in Retrieval-Augmented Generation

Retrieval-augmented generation (RAG) aggregates evidence from multiple external documents, yet this joint integration creates an underexamined vulnerability: attack effects absent in individual documents can emerge through set-level composition. Existing coordinated attacks do not explicitly enforce that every proper subset remains insufficient in frozen single-round RAG. We formalize set-level compositional poisoning, where documents designed to remain individually plausible jointly redirect RAG outputs to a target answer, while proper subsets fail to induce the target on their own. To construct such attacks, we propose LENS, a generator-black-box multi-agent framework that casts construction as constrained evidence composition. LENS factorizes target inference into a query-conditioned interpretation lens and complementary facts, then uses a nested dual-loop workflow to concentrate steering in the full set while suppressing subset leakage. The outer loop plans the interpretation lens and semantic roles; the inner loop synthesizes documents and applies counterexample-guided repair. Across four benchmarks and three generators, returned packets achieve 0.852 full-set ASR and 0.784 post-retrieval ASR@5, while their strongest proper subsets reach only 0.069. Against construction baselines evaluated on the same frozen manifest, LENS improves all-attempt E2E-Strict@5 from 0.244 to 0.363, a 48.8% relative gain. A blinded human audit finds that 68.3% of returned packets combine an incorrect target, a definite answer-criterion shift, and no target entailment under the original semantics. Across four published defenses, LENS attains the highest defended all-attempt ASR@5, exceeding the strongest baseline by 0.141 on average. Together, these results establish evidence composition as a distinct RAG security boundary and position LENS as a stress test for defenses that reason over document sets.
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All authors Kaisheng Fan, Yishu Gao, Xunzhu Tang, Tegawend'e F. Bissyand'e, Weizhe Zhang

Cryptography and Security · Cross-listed from cs.AI

When Valid Tool Calls Change Meaning: Formation-Consistent Dispatch for LLM Agents

Tool-enabled agents form calls from model-visible interfaces, while hosts later select their implementation. Standard dispatch omits the descriptor-handler relation. An unchanged and schema-valid call can therefore acquire a different security effect during rollout, reconnect, or delayed approval. We call this failure schema-epoch drift. We present formation-consistent dispatch (FCD), which connects implementation analysis to execution authority. Reviewed profiles produce provenance-bound over-approximations of declared in-scope effects from official source. Under a closed-target approval policy, a verifier applies each formed call to a summary and captures a successor only when its effects fit the call's security contract. Atomic admission and a final-hop fence preserve this decision to the effect. The exact source retains priority, and the captured successor becomes eligible only after source retirement. Stock releases and deployment changes reproduced the failure. Four profiles covered 32 official releases: 29 required no release-specific change and three escalated. A frozen 16-release expansion matched a separate source oracle. In a preregistered stock comparison, FCD completed all three pending calls whose effect remained private and blocked all three whose omission became public. Exact pinning and release-wide denial stopped all six calls, while release-wide approval completed all six but produced three public effects. A separate lifecycle experiment carried a formation-captured certificate across source retirement. The same safe certificate installed later governed new formations without expanding the pending call's authority.
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Cryptography and Security

Efficient TCitH-Based Alternatives to SLH-DSA: Cross-Layer ASIC Design of Mirath

To address the security risks posed by quantum computers, the U.S. National Institute of Standards and Technology (NIST) has standardized the post-quantum signature schemes ML-DSA, FN-DSA, and SLH-DSA. While ML-DSA and FN-DSA are lattice-based, SLH-DSA relies on hash-based assumptions. To support cryptographic agility against future vulnerabilities, NIST is evaluating non-lattice candidates as alternatives to SLH-DSA. Among these, TCitH-based schemes are particularly promising due to their compact keys and small signatures. However, their high computational complexity and memory footprint pose significant challenges for efficient implementations on resource-constrained embedded platforms. They remain largely unexplored in this context, particularly in ASIC implementations. To address this gap, we use a cross-layer methodology combining algorithmic and hardware layers to present, to the best of our knowledge, the first ASIC implementation of Mirath, a TCitH-based signature scheme, in a RISC-V-based system. The design is implemented in a 22nm FD-SOI technology node. Compared with an SLH-DSA ASIC implemented in the same technology node, the proposed architecture achieves 17.8x lower signing latency while requiring 58% less total cell area, showing the potential of TCitH-based signatures as efficient non-lattice alternatives from an implementation perspective.
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All authors Hiandra Tomasi, Maximilian Schöffel, Johannes Feldmann, Norbert Wehn

Cryptography and Security

GAZEleak: Passcode Inference Against Eye-tracking XR Devices Through External Observation

Mixed-reality headsets such as Apple Vision Pro replace the touch screen with gaze-as-pointer interaction: the wearer looks at a target and confirms with an air pinch. Because the display is inside the headset and the eye tracker is walled off from third-party software, such input is widely assumed to be unobservable to bystanders—a built-in defense against the shoulder-surfing that plagues phones and laptops. We present GAZEleak, a side-channel attack that recovers gaze-driven input from external video of head motion alone, under a strictly local, physical-observer threat model: the adversary only films the wearer from across the room and installs no software on the device. The attack exploits the centrally coupled eye-head motor program: gaze shifts recruit small, target-dependent head reorientations that project into sub-degree pose changes recoverable from commodity video. GAZEleak implements a measurement-based, sparse-optical-flow inference pipeline for users' 6-digit device passcodes. On a preliminary front-view dataset from three author-subjects who were aware of the attack hypothesis, GAZEleak places the true code within the top ten guesses for 56% (10 of 18) of test codes under a cross-person protocol with no labeled victim data, and for every code of the most exposed subject. The performance is subject-dependent: no passcode from the least exposed subject reaches the top ten, although its median guessed passcode rank is 12,786 rather than 500,000 expected from an uninformative ordering. These results provide preliminary evidence that gaze-coupled head motion can expose passcode information under controlled conditions, while motivating broader evaluation across users, behaviors, and capture settings.
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Cryptography and Security · Cross-listed from cs.CV

Still There, No Longer Seen: Exposing Compression-Induced Risk in Large Vision-Language Models

Visual token compression reduces the inference cost of Large Vision-Language Models (LVLMs). However, aggregate robustness measures do not reveal whether a particular adversarial failure is induced by compression or inherited from the underlying model. We define a compression-specific failure (CSF) as an adversarial input that remains correct under full-token inference but fails after compression, casting compression-induced risk as a paired failure attribution problem. Within a controlled diagnostic cohort, counterfactuals show that retained-set allocation causally changes compressed correctness and reveal a negative association between recovery and representation drift in displaced evidence. Motivated by these findings, we propose CIRA, a Compression-Induced Risk Attack for Large Vision-Language Models. Under a vision-encoder white-box setting, CIRA optimizes image perturbations through encoder-side objectives that manipulate token priorities across candidate compression budgets while preserving displaced evidence. CIRA uses no downstream questions or labels and requires no access to the language model, deployed compressor, or exact compression budget. Across 12 dataset-compressor settings evaluated at four budgets, CIRA achieves a mean CSFR of 20.35% while limiting full-token attack success to 6.92%, with similar behavior on additional LVLM families. A cross-view selection-stabilization defense substantially suppresses CIRA, although Adaptive CIRA partially restores its effectiveness. These results show that compression-specific failures persist under restricted access and support paired evaluation of full-token and compressed inference for attributing risk to visual-token compression.
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All authors Qiankun Li, Yuechen Zhang, Bowen Chen, Shilinlu Yan, Zhenhong Zhou, Kun Wang, Li Sun