Cryptography and Security
CRT-Decomposed $\Sigma$-Protocols for CSIDH
I. Dey and I. Cherkaoui
We construct a zero-knowledge proof of knowledge for the CSIDH group action that exploits the Chinese Remainder
Theorem (CRT) structure of the ideal class group, available whenever the group structure is known exactly, as for CSIDH-512. We prove perfect completeness, perfect special honest-verifier zero-knowledge, and 2-special soundness, in which the secret is recovered from two accepting transcripts by one subtraction and one modular inversion per CRT component; no rewinding loop,
lattice reduction, or heuristic sampling appears in the extractor. Because each round admits exactly two responses, Unruh's transform yields a non-interactive proof with straight-line extraction in the
quantum random oracle model (QROM), removing the multiplicative forking-lemma loss. We instantiate the scheme on the CSIDH-512 class group, verify the algebraic layer by machine over the exact 258-bit modulus ($10^4$ random instances, all passing), and report protocol-level simulations in the exponent model: Monte Carlo soundness rates matching the proven $2^{-t}$ bound within 95% confidence at every tested $t$, serialized signature sizes within 1.6% of the formulas, instrumented action counts, and a scaled meet-in-the-middle attack whose measured cost follows the predicted $\sqrt{q}$ law. We further prove two delimiting results: CRT decomposition cannot enlarge the per-round challenge space, and publishing the CRT hop curves lowers classical key-recovery cost from about $2^{128.6}$ to about $2^{67.3}$ group action evaluations. The construction is therefore correct and structurally complete today, but quantitatively secure only on future parameters whose class number has large
prime factors. We compare against CSI-FiSh, CSI-Otter, and Tanuki; a tightly secure blind signature from this proof of knowledge is left to future work.
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Cryptography and Security
Not Discrete Enough: On the Inherent Insecurity of dTPMs for Measured Boot
Christian Werling, Tahmid Zahin and Jean-Pierre Seifert
Measured Boot, a mechanism enabled through Trusted Platform Modules (TPMs), is commonly used for passwordless protection of data-at-rest, aiming to protect data when the device is lost or stolen. Microsoft's standpoint is neutral on which way a TPM should be implemented: Firmware-based TPMs (fTPMs) are viewed as more economical but less secure. Despite the inherent susceptibility to bus sniffing attacks, discrete TPMs (dTPMs) are still seen as the gold standard, as many deliver better on-paper tamper resistance. It is often argued that attacks against the bus can be mitigated by bus encryption and, ideally, mutual authentication between the CPU and TPM. This position paper aims to emphasize another inherent, difficult-to-mitigate attack against dTPMs that was originally shown against a TPM 1.1 over 20 years ago: We demonstrate that even brief physical access to a TPM 2.0 and the ability to boot from an attacker-controlled system enable an attacker to reset and replay arbitrary measurements, thereby allowing an attacker to unseal, for example, a disk encryption key solely protected by the TPM. While there have been attacks against fTPMs, too, we argue that their practical attack surface is fundamentally smaller. Bus protection techniques can be used to protect dTPMs, but only guard against passive attacks. After all, we argue that, from a security standpoint, firmware TPMs, or any TPM internal to the SoC, are superior to discrete (external) ones. Lastly, in order for dTPM-based setups to provide meaningful protection of sealed secrets, configurations must require a user-provided PIN or password along with the Measured Boot configuration.
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Cryptography and Security
AccretionLink: On-Device Auditing of Exposure-Control Attacks on Attribute Inference
Faruk Alpay and Taylan Alpay
Exposure control lets an adversary rank authentic public posts to strengthen private-attribute inference without altering content. AccretionLink defines confidentiality and integrity games for this attack, models bounded selection odds through partial identification, and constructs dependence-aware time-uniform e-processes. On 52 held-out synthetic profiles, odds-four selection reduced aggregate negative log likelihood at every horizon. At eight posts the advantage was 0.01595 nats (95% CI [0.00890, 0.02336]), three of four target effects survived Holm adjustment, and label-blind model-guided selection caused 6/109 high-confidence false reversals. On 142 PAN15 test profiles, exploratory selection produced a 0.01227-nat advantage but no reversal. A separate TF-IDF selector retained a 0.01470-nat advantage against the unchanged G5 target, while matched identity shuffling did not reproduce it. Pixel 10 encoded all 1,622 held-out posts once with a fallback-free Tensor G5 graph. A P-256 checkpoint authenticated the selected-replay, actual-model, native-report, and operation digests; local KeyInfo identified the signing key as StrongBox-backed.
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Cryptography and Security · Cross-listed from cs.CV
IP Protection in the Era of Visual Generative AI: A Survey
Zhuan Shi, Shunchang Liu, Alireza Dehghanpour Farashah et al. (+8 more)
The rapid
evolution of visual generative AI has introduced a wide range of intellectual property risks, spanning the unauthorized learning, reproduction, extraction, misuse, and redistribution of protected data and model assets. To address these risks, a growing body of technical defenses has been proposed. However, existing surveys typically organize this literature by lifecycle stage or technical mechanism, which can obscure the protective intent of different methods. This survey presents a two-dimensional taxonomy for IP protection in visual generative models. The primary axis is a Control Logic View, which classifies methods into Information Exposure Control, Generative Behavior Constraint, and Attribution & Accountability according to the risk variable they regulate. The secondary axis distinguishes Data IP from Model IP as cross-cutting asset dimensions. Under this framework, we systematically review protection methods, align evaluation protocols with protection objectives, and discuss open challenges including proactive model-level safeguards, standardized evaluation, robustness against adaptive attacks, and explainable evidence. This survey aims to offer a principled, systematic, and easy-to-follow overview for both new and experienced researchers in visual generative AI IP protection.
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All authors Zhuan Shi, Shunchang Liu, Alireza Dehghanpour Farashah, Qian Yang, Han Yu, Cao Yang, Chaochao Chen, Yuping Yan, Yaochu Jin, Golnoosh Farnadi, Lingjuan Lyu
Cryptography and Security
TLF: Rapid Characterization of RF Transceiver Parameters in Embedded Systems via Bus-Level Interception
Larry Hernandez and Sergey Bratus
We present TLF (Transceiver Lifter Framework), a tool for recovering RF transceiver configuration and runtime behavior from bus-level traces captured between a microcontroller and its transceiver IC. A stateful protocol decoder, built against the transceiver's register and data interface, reconstructs operating RF parameters and behavior from intercepted register writes and FIFO transfers. For bus-attached transceivers whose hardware-cryptography keys are loaded through the intercepted host interface, key material is also recoverable. Where the firmware drives frequency hopping – either through a hardware-assisted engine or a custom schedule – the decoder extracts the channel table, hop sequence, and timing. We evaluate the approach on two targets from different Semtech families: an SX1233-based
UAV C2 modem employing firmware-level FHSS with per-packet sync word rotation, and an SX1276-based Meshtastic node exercising the LoRa register overlay. From a single bus capture, processed in seconds, TLF recovers the complete register-exposed RF configuration (modulation, band plan, phase behavior) without prior knowledge of the target firmware – sufficient to configure a matched receiver or develop targeted countermeasures. Above the chip layer, a pluggable protocol decoder interprets recovered FIFO payloads as application PDUs, demonstrated end-to-end on Meshtastic. Firmware-level cryptographic state remains, as expected, opaque. The approach requires physical access or emulation of the target hardware, and its recovery depth is bounded by the transceiver's register interface: parameters implemented entirely in firmware (custom FEC, whitening, encryption) are observable only as opaque FIFO payloads.
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Cryptography and Security
Vaulted Passkeys: A Device-Bound Proposal for Authenticated Credential Export and Import
Pol Henarejos
Hardware authenticators deliberately resist private-key extraction, yet replacement, disaster recovery, and controlled migration create a legitimate need for portability. Existing guidance for device-bound credentials commonly reduces recovery risk by registering an additional authenticator before failure. That creates an independent credential registration and requires replacement hardware to exist in advance; it is redundancy, not a backup of the original credential. This paper addresses the resulting recovery gap by exporting protected credential state while the source is available and restoring it to hardware acquired later, without cloning a complete authenticator or exposing plaintext private keys to routine desktop software. We propose Vaulted Passkeys, a device-bound architecture in which a random 256-bit Kvault protects authenticated PKV1 credential envelopes through HKDF-separated keys and four explicit AEAD profiles. The design separates enrollment from export/import and the required vault from optional identity. We contribute a role-separated system model, wire format, threat analysis, implementation mapping, and falsifiable evaluation plan. The prototype demonstrates feasibility but is neither a formal security proof nor a proposed final standard.
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Cryptography and Security
Mobile Apps vs. Web Browsers: A User Perception Study with Android Apps and Google Chrome
Harel Berger
This study examines user perceptions of mobile applications (apps) versus web browsers for accessing online services, with an emphasis on security,
privacy, and usability aspects. Through a combination of an experiment and a survey with Android smartphone users, the research seeks to identify the key concerns and preferences that influence their choice between mobile apps and web browsers. The findings will offer valuable insights for developers to improve the security,
privacy, and usability of both platforms by addressing user concerns and misconceptions.
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Cryptography and Security
The ack3 H1 2026 DeFi Incident Dataset: Audit Scope Across 135 Security Incidents
Josef Gattermayer, Jan Kalivoda and Arman Bašović
Smart-contract audits cover defined artifacts at a specific time, but the label audited is often treated as project-wide assurance. We analyze audit history and incident-path scope across 135 DeFi security incidents using the H1 2026 DeFi Incident
Dataset published by cybersecurity company ack3 (https://ack3.ai), covering 1 January to 29 June 2026. The corpus reports USD 939.86 million in attributed loss. Audit history was identified for 68 incidents. Of these, 46 attack paths were outside all identified public pre-incident audit scopes, 20 were inside at least one scope, and 2 were unresolved. Within this 68-incident subset, outside-scope paths represented 67.6% by count and 94.4% of reported loss. The loss-weighted result was concentrated in two large incidents; excluding both reduced the share to 72.1%, while preserving the direction of the result. We also describe audit age, temporal loss distribution, and affected project types. The results show that project-level audit history and incident-path scope are distinct variables.
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Cryptography and Security
A Reproducibility Protocol for Cross-Implementation Evaluation of Post-Quantum ACVP Test Vectors
Christopher M. Frost
Independent implementations of a cryptographic standard should reproduce the same known-answer results, yet agreement is meaningful only when the corpus, revisions, public interfaces, exclusions, and evidence are precisely stated. This study defines a product-neutral reproducibility protocol for three public implementations of NIST ML-KEM against a pinned public Automated Cryptographic Validation Protocol corpus. Protocol v2 freezes provider-specific capabilities, applies one validation-error taxonomy symmetrically, preserves every selected case, and separates bytes, validation verdicts, unsupported operations, and adapter errors. The source-built experiment evaluated @noble/post-
quantum 0.7.0, liboqs 0.16.0, and Go 1.26.4. Across three repetitions, the required Cartesian product comprised 2,160 base records: all 1,650 declared executable evaluations matched the NIST oracle, and all 510 unsupported records matched Go's predeclared capability boundary. Pairwise agreement was complete on every executable overlap: 720 of 720 noble-liboqs records and 210 of 210 records for each Go pairing. A separate keyGen-ek-projection diagnostic matched all 150 Go encapsulation-key projections without counting them as full key generation. Three frozen controls independently exercised byte comparison, verdict comparison, and malformed-response error separation; each produced its exact predeclared outcome. No base failure, adapter error, or status instability occurred. The evidence establishes bounded author-run repeatability and exposes a practical standards gap: public ML-KEM packages provide materially different deterministic and validation-test surfaces. Independent external reproduction remains unobserved. The results do not establish certification, exhaustive correctness, side-channel resistance, secure integration, or production assurance.
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Cryptography and Security
Weird Machines in Transport Layer Security
Michael Collins, Jada Cumberland, Brianne Dunn et al. (+4 more)
Weird machines are latent computational capabilities that emerge from the composition of architectural components. Prior work has studied this phenomenon extensively in software systems, including x86 instructions, ELF metadata, and page tables, and more recently in cyber-physical systems such as industrial control networks. This paper extends weird machine theory to a new domain: the Transport Layer Security (TLS) handshake and its two dominant implementations, OpenSSL and BoringSSL. We show that legitimate TLS primitives, including session cache entries, renegotiation logic, extension parsing, and certificate verification steps, compose into Turing-complete systems whose computation is coupled to authentication and trust decisions rather than physical actuation. We formalize this coupling, which we call trust actuation, and argue that any TLS implementation providing session storage, arithmetic on sequence counters, conditional branching on handshake state, and iteration through resumption or retry loops satisfies the conditions for arbitrary computation. We validate this theory with two working demonstrations built on real OpenSSL code paths. The first, a sentinel system, composes standard TLS primitives into a defensive mechanism that detects anomalous handshake behavior. The second, an authentication bypass, composes the same class of primitives into an attack that defeats a cipher-strength policy check through mid-connection renegotiation, without any
memory corruption or external malware. Both demonstrations run against real server and client binaries in Docker.
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All authors Michael Collins, Jada Cumberland, Brianne Dunn, Ross Gore, Samuel Jackson, Sachin Shetty, Jonathan Takeshita
Cryptography and Security
"I Thought You Were The Uncensored Place": Norms, Rules, and Moderation in AI-Generated Sexual Content Communities
Lucy Qin, Jaron Mink and Elissa M. Redmiles
As AI-generated sexual content (AIG-SC) is increasingly produced, online communities have emerged to support creators' needs. To understand whether and how community governance attempts work to prevent abuse while supporting free expression, we interviewed 24 members and moderators of large AIG-SC online communities (10,000+ members) with stated rules against creating and sharing abusive content (e.g., AI-generated CSAM). Through in-depth interviews, we offer insight into: (1) how and why these communities form; (2) implicit community norms; (3) explicitly stated rules—and their operationalization via content moderation; and (4) tensions between community values and moderation that leave space for abusive behavior. Our findings reveal a complex picture: while many creators and communities have personal boundaries against abuse, advice and resources for creating any form of AI-generated sexual content are accessible to users regardless of their intentions. Further complicating community moderation are norms that center anti-censorship and non-judgment, which leave moderators to justify their actions using the limits of the law and terms of service. We end by reflecting on the ways in which technical, community, and legal governance may most effectively mitigate the production of abusive content.
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Cryptography and Security · Cross-listed from cs.LG
Concept Drift Detection and Adaptive Retraining of Malware Classification Models
Christofer Washington Berruz Chungata, Martin Jurecek, Katerina Potika et al. (+2 more)
Concept drift refers to changes over time in the statistical properties of data, as compared to the data that was used to train a learning model. Machine learning models for malware detection or classification are particularly susceptible to performance degradation caused by concept drift, as attackers constantly modify existing malware. In this chapter, we analyze two machine learning-based approaches to automated concept drift detection-a novel approach based on One-Class Support Vector Machines (OCSVM) and a previously-studied technique based on Minibatch K-Means (MK-Means). For comparison we also consider Maximum Mean Discrepancy (MMD), a statistical technique for detecting changes in multidimensional data. We conduct an extensive series of experiments comparing the effectiveness of four learning models, namely, Multilayer Perceptron, Random Forest, Support Vector Machines, and eXtreme Gradient Boosting. For each of these models, we consider three distinct scenarios: A static scenario where no model retraining occurs, a periodic scenario where models are constantly retrained irrespective of concept drift, and a drift-aware scenario where models are only retrained when concept drift is detected. Under the drift-aware scenario, we analyze the tradeoff between accuracy and training efficiency using Pareto Front analysis. We find that all three concept drift detection techniques achieve classification accuracy comparable to periodic retraining, while offering substantially greater efficiency in terms of the number of models that must be retrained. In addition, drift-aware retraining based on our OCSVM technique generally outperforms the MK-Means and MMD approaches. Overall, these results provide strong evidence that we can accurately detect concept drift in malware classification models.
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All authors Christofer Washington Berruz Chungata, Martin Jurecek, Katerina Potika, William B. Andreopoulos, Mark Stamp
Cryptography and Security · Cross-listed from cs.SE
LLM-Assisted Dynamic Threat Analysis for Attacker-Reachable Software Weaknesses in Autonomous Vehicles
Md Wasiul Haque, Sagar Dasgupta, Mizanur Rahman et al. (+1 more)
Autonomous vehicles depend on large safety-critical software stacks, where weaknesses reachable from
adversarial inputs may affect steering, braking, or other control decisions. Static analysis can identify candidate sites, but dynamically confirming exploitability requires executable test artifacts that are difficult to construct manually. We investigate whether large
language models (LLMs) can automate this process for Autoware, an open-source autonomous-driving stack. We perform compiler-precise static analysis across 185 packages, identifying 1,375 decision rules, 2,274 validation checks, and 482 input-to-safety-output flows, from which we derive a weakness taxonomy and sample 740 reachable sites. Two local open-weight LLMs, a no-static-context ablation, and a naive-template baseline generate 3,700 artifact sets, which are compiled against the real build under sanitizers, repaired through compiler-in-the-loop feedback, and fuzzed when executable. The main result is a build-integration failure taxonomy showing that 80% of first-shot compilation failures arise from dependency wiring rather than program logic. The
reasoning model compiled 64% of harnesses on the first attempt, compared with 6% for the code-specialized model. Repair achieved full object-compileability for the
reasoning model only through extensive stubbing; fewer than half of its harnesses reached the fuzzer, and all 37 observed crashes originated in stubbed code rather than Autoware. No candidate weakness was dynamically confirmed within budget. These results show that build integration, not candidate generation or fuzzing, is the primary barrier to reliable LLM-assisted dynamic analysis of full autonomous-vehicle software stacks.
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All authors Md Wasiul Haque, Sagar Dasgupta, Mizanur Rahman, Md Rayhanur Rahman