Cryptography and Security
Data-Chain Backdoor: Do You Trust Diffusion Models as Generative Data Supplier?
Junchi Lu, Xinke Li, Yuheng Liu et al. (+1 more)
The increasing use of generative models such as
diffusion models for synthetic data augmentation has greatly reduced the cost of data collection and labeling in downstream perception tasks. However, this new data source paradigm may introduce important security concerns. Publicly available generative models are often reused without verification, raising a fundamental question of their safety and trustworthiness. This work investigates
backdoor propagation in such emerging generative data supply chain, namely, Data-Chain
Backdoor (DCB). Specifically, we find that open-source
diffusion models can become hidden carriers of
backdoors. Their strong distribution-fitting ability causes them to memorize and reproduce
backdoor triggers in generation, which are subsequently inherited by downstream models, resulting in severe security risks. This threat is particularly concerning under clean-label attack scenarios, as it remains effective while having negligible impact on the utility of the synthetic data. We study two attacker choices to obtain a
backdoor-carried generator, training from scratch and fine-tuning. While naive fine-tuning leads to weak inheritance of the
backdoor, we find that novel designs in the loss objectives and trigger processing can substantially improve the generator's ability to preserve trigger patterns, making fine-tuning a low-cost attack path. We evaluate the effectiveness of DCB under the standard augmentation protocol and further assess data-scarce settings. Across multiple trigger types, we observe that the trigger pattern can be consistently retained in the synthetic data with attack efficacy comparable to the conventional
backdoor attack.
Read the full abstract ▾
All authors Junchi Lu, Xinke Li, Yuheng Liu, Qi Alfred Chen
Cryptography and Security
PHANTOM: Progressive High-fidelity Adversarial Network for Threat Object Modeling
Jamal Al-Karaki, Muhammad Al-Zafar Khan and Rand Derar Mohammad Al Athamneh
The scarcity of cyberattack data hinders the development of robust intrusion detection systems. This paper introduces PHANTOM, a novel
adversarial variational framework for generating high-fidelity synthetic attack data. Its innovations include progressive training, a dual-path VAE-GAN architecture, and domain-specific feature matching to preserve the semantics of attacks. Evaluated on 100,000 network traffic samples, models trained on PHANTOM data achieve 98% weighted accuracy on real attacks. Statistical analyses confirm that the synthetic data preserves authentic distributions and diversity. Limitations in generating rare attack types are noted, highlighting challenges with severe class imbalance. This work advances the generation of synthetic data for training robust,
privacy-preserving detection systems.
Read the full abstract ▾
Cryptography and Security
A Survey on Reconfigurable Intelligent Surfaces in Practical Systems: Security and Privacy Perspectives
Ziyu Chen, Yitong Shen, Jingzhe Zhang et al. (+5 more)
Reconfigurable Intelligent Surfaces (RIS) have emerged as a transformative technology capable of reshaping wireless environments through dynamic manipulation of electromagnetic waves. While extensive research has explored their theoretical benefits for communication and sensing, practical deployments in smart environments such as homes, vehicles, and industrial settings remain limited and under-examined, particularly from security and
privacy perspectives. This survey provides a comprehensive examination of RIS applications in real-world systems, with a focus on the security and
privacy threats, vulnerabilities, and defensive strategies relevant to practical use. We analyze scenarios with two types of systems (with and without legitimate RIS) and two types of attackers (with and without malicious RIS), and demonstrate how RIS may introduce new attacks to practical systems, including eavesdropping, jamming, and spoofing attacks. In response, we review defenses against RIS-related attacks in these systems, such as applying additional security
algorithms, disrupting attackers, and early detection of unauthorized RIS. We also discuss scenarios in which the legitimate user applies an additional RIS to defend against attacks. To support future research, we also provide a collection of open-source tools,
datasets, demos, and papers at: https://awesome-ris-security.github.io/. By highlighting RIS's functionality and its security/
privacy challenges and opportunities, this survey aims to guide researchers and engineers toward the development of secure, resilient, and
privacy-preserving RIS-enabled practical wireless systems and environments.
Read the full abstract ▾
All authors Ziyu Chen, Yitong Shen, Jingzhe Zhang, Yao Zheng, Yili Ren, Xuyu Wang, Shiwen Mao, Hanqing Guo
Cryptography and Security
BLINDSPOT: Enabling Bystander-Controlled Privacy Signaling for Camera-Enabled Devices
Jad Al Aaraj and Athina Markopoulou
Camera-equipped mobile devices, such as phones, smart glasses, and AR headsets, pose a
privacy challenge for bystanders, who currently lack effective real-time mechanisms to control the capture of their picture,
video, including their face. We present BlindSpot, an on-device system that enables bystanders to manage their own
privacy by signaling their
privacy preferences in real-time without previously sharing any sensitive information. Our main contribution is the design and comparative evaluation of three distinct signaling modalities: a hand gesture mechanism, a significantly improved visible light communication (VLC) protocol, and a novel ultra-wideband (UWB) communication protocol. For all these modalities, we also design a validation mechanism that uses
geometric consistency checks to verify the origin of a signal relative to the sending bystander, and defend against impersonation attacks. We implement the complete system (BlindSpot) on a commodity smartphone and conduct a comprehensive evaluation of each modality's accuracy and latency across various distances, lighting conditions, and user movements. Our results demonstrate the feasibility of these novel bystander signaling techniques and their trade-offs in terms of system performance and convenience.
Read the full abstract ▾
Cryptography and Security
Factor(U,T): Controlling Untrusted AI by Monitoring their Plans
Edward Lue Chee Lip, Anthony Channg, Diana Kim et al. (+2 more)
As AI capabilities advance, we increasingly rely on powerful models to decompose complex tasks $\unicode{x2013}$ but what if the decomposer itself is malicious? Factored cognition protocols decompose complex tasks into simpler child tasks: one model creates the decomposition, while other models implement the child tasks in isolation. Prior work uses trusted (weaker but reliable) models for decomposition, which limits usefulness for tasks where decomposition itself is challenging. We introduce Factor($U$,$T$), in which an untrusted (stronger but potentially malicious) model decomposes while trusted models implement child tasks. Can monitors detect malicious activity when observing only natural
language task instructions, rather than complete solutions? We baseline and red team Factor($U$,$T$) in control evaluations on BigCodeBench, a
dataset of Python coding tasks. Monitors distinguishing malicious from honest decompositions perform poorly (AUROC 0.52) compared to monitors evaluating complete Python solutions (AUROC 0.96). Furthermore, Factor($D$,$U$), which uses a trusted decomposer and monitors concrete child solutions, achieves excellent discrimination (AUROC 0.96) and strong safety (1.2% ASR), demonstrating that implementation-context monitoring succeeds where decomposition-only monitoring fails.
Read the full abstract ▾
All authors Edward Lue Chee Lip, Anthony Channg, Diana Kim, Aaron Sandoval, Kevin Zhu
Cryptography and Security
Quantum-Augmented AI/ML for O-RAN: Hierarchical Threat Detection with Synergistic Intelligence and Interpretability (Technical Report)
Tan Le, Van Le and Sachin Shetty
Open
Radio Access Networks (O-RAN) enhance modularity and telemetry granularity but also widen the cybersecurity attack surface across disaggregated control, user and management planes. We propose a hierarchical defense framework with three coordinated layers-anomaly detection, intrusion confirmation, and multiattack classification-each aligned with O-RAN's telemetry stack. Our approach integrates hybrid
quantum computing and machine learning, leveraging amplitude- and
entanglement-based feature encodings with deep and ensemble classifiers. We conduct extensive benchmarking across synthetic and real-world telemetry, evaluating encoding depth, architectural variants, and diagnostic fidelity. The framework consistently achieves near-perfect accuracy, high recall, and strong class separability. Multi-faceted evaluation across decision boundaries, probabilistic margins, and latent space geometry confirms its interpretability, robustness, and readiness for slice-aware diagnostics and scalable deployment in near-RT and non-RT RIC domains.
Read the full abstract ▾
Cryptography and Security
Persistent Backdoor Attacks under Continual Fine-Tuning of LLMs
Jing Cui, Yufei Han, Jianbin Jiao et al. (+1 more)
Backdoor attacks embed malicious behaviors into Large
Language Models (LLMs), enabling adversaries to trigger harmful outputs or bypass safety controls. However, the persistence of the implanted
backdoors under user-driven post-deployment continual fine-tuning has been rarely examined. Most prior works evaluate the effectiveness and generalization of implanted
backdoors only at releasing and empirical evidence shows that naively injected
backdoor persistence degrades after updates. In this work, we study whether and how implanted
backdoors persist through a multi-stage post-deployment fine-tuning. We propose P-Trojan, a trigger-based attack
algorithm that explicitly optimizes for
backdoor persistence across repeated updates. By aligning poisoned gradients with those of clean tasks on
token embeddings, the implanted
backdoor mapping is less likely to be suppressed or forgotten during subsequent updates. Theoretical analysis shows the feasibility of such persistent
backdoor attacks after continual fine-tuning. And experiments conducted on the Qwen2.5 and LLaMA3 families of LLMs, as well as diverse task sequences, demonstrate that P-Trojan achieves over 99% persistence while preserving clean-task accuracy. Our findings highlight the need for persistence-aware evaluation and stronger defenses in realistic model adaptation pipelines.
Read the full abstract ▾
All authors Jing Cui, Yufei Han, Jianbin Jiao, Junge Zhang
Cryptography and Security
Verification of Lightning Network Channel Balances with Trusted Execution Environments (TEE)
Vikash Singh, Barrett Little, Philip Hayes et al. (+4 more)
Verifying the private liquidity state of Lightning Network (LN) channels is desirable for auditors, service providers, and network participants who need assurance of financial capacity. Current methods often lack robustness against a malicious or compromised node operator. This paper introduces a methodology for the verification of LN channel balances. The core contribution is a framework that combines Trusted Execution Environments (TEEs) with Zero-Knowledge Transport Layer Security (zkTLS) to provide strong, hardware-backed guarantees. In our proposed method, the node's balance-reporting software runs within a TEE, which generates a remote attestation quote proving the software's integrity. This attestation is then served via an Application Programming Interface (API), and zkTLS is used to prove the authenticity of its delivery. We also analyze an alternative variant where the TEE signs the report directly without zkTLS, discussing the trade-offs between transport-layer verification and direct enclave signing. We further refine this by distinguishing between "Hot Proofs" (verifiable claims via TEEs) and "Cold Proofs" (on-chain settlement), and discuss critical security considerations including hardware vulnerabilities,
privacy leakage to third-party APIs, and the performance overhead of enclaved operations.
Read the full abstract ▾
All authors Vikash Singh, Barrett Little, Philip Hayes, Max Fang, Matthew Khanzadeh, Alyse Killeen, Sam Abbassi
Cryptography and Security · Cross-listed from cs.CV
SPDMark: Selective Parameter Displacement for Robust Video Watermarking
Samar Fares, Nurbek Tastan and Karthik Nandakumar
The advent of high-quality
video generation models has amplified the need for robust watermarking schemes that can be used to reliably detect and track the provenance of generated
videos. Existing
video watermarking methods based on both post-hoc and in-generation approaches fail to simultaneously achieve imperceptibility, robustness, and computational efficiency. This work introduces a novel framework for in-generation
video watermarking called SPDMark (pronounced `SpeedMark') based on selective parameter displacement of a
video diffusion model. Watermarks are embedded into the generated
videos by modifying a subset of parameters in the generative model. To make the problem tractable, the displacement is modeled as an additive composition of layer-wise basis shifts, where the final composition is indexed by the watermarking key. For parameter efficiency, this work specifically leverages low-rank adaptation (LoRA) to implement the basis shifts. During the training phase, the basis shifts and the watermark extractor are jointly learned by minimizing a combination of message recovery, perceptual similarity, and temporal consistency losses. To detect and localize temporal modifications in the watermarked
videos, we use a cryptographic hashing function to derive frame-specific watermark messages from the given base watermarking key. During watermark extraction, maximum bipartite matching is applied to recover the correct frame order, even from temporally tampered
videos. Evaluations on both text-to-
video and image-to-
video generation models demonstrate the ability of SPDMark to generate imperceptible watermarks that can be recovered with high accuracy and also establish its robustness against a variety of common
video modifications.
Read the full abstract ▾
Cryptography and Security · Cross-listed from cs.LG
CLOAK: Contrastive Guidance for Latent Diffusion-Based Data Obfuscation
Xin Yang and Omid Ardakanian
Data obfuscation is a promising technique for mitigating attribute inference attacks by semi-trusted parties with access to time-series data emitted by sensors. Recent advances leverage conditional generative models together with
adversarial training or mutual information-based regularization to balance data
privacy and utility. However, these methods often require modifying the downstream task, struggle to achieve a satisfactory
privacy-utility trade-off, or are computationally intensive, making them impractical for deployment on resource-constrained mobile IoT devices. We propose Cloak, a novel data obfuscation framework based on latent
diffusion models. In contrast to prior work, we employ contrastive learning to extract disentangled representations, which guide the latent
diffusion process to retain useful information while concealing private information. This approach enables users with diverse
privacy needs to navigate the
privacy-utility trade-off with minimal retraining. Extensive experiments on four public time-series
datasets, spanning multiple sensing modalities, and a
dataset of facial images demonstrate that Cloak consistently outperforms state-of-the-art obfuscation techniques, reducing utility loss by up to 7.21% and
privacy loss by up to 5.76%, and is well-suited for deployment in resource-constrained settings.
Read the full abstract ▾
Cryptography and Security
The Procedural Semantics Gap in Structured CTI: A Measurement-Driven STIX Analysis for APT Emulation
Ágney Lopes Roth Ferraz, Sidnei Barbieri, Murray Evangelista de Souza et al. (+1 more)
Cyber threat intelligence (CTI) encoded in STIX and structured according to the MITRE ATT&CK framework has become a global reference for describing adversary behavior. However, ATT&CK was designed as a descriptive knowledge base rather than a procedural model. We therefore ask whether its structured artifacts contain sufficient behavioral detail to support multi-stage adversary emulation. Through systematic measurements of the ATT&CK Enterprise bundle, we show that campaign objects encode just fragmented slices of behavior. Only 35.6% of techniques appear in at least one campaign, and neither clustering nor sequence analysis reveals any reusable behavioral structure under technique overlap or LCS-based analyses. Intrusion sets cover a broader portion of the technique space, yet omit the procedural semantics required to transform behavioral knowledge into executable chains, including ordering, preconditions, and environmental assumptions. These findings reveal a procedural semantic gap in current CTI standards: they describe what adversaries do, but not exactly how that behavior was operationalized. To assess how far this gap can be bridged in practice, we introduce a three-stage methodology that translates behavioral information from structured CTI into executable steps and makes the necessary environmental assumptions explicit. We demonstrate its viability by instantiating the resulting steps as operations in the MITRE Caldera framework. Case studies of ShadowRay and Soft
Cell show that structured CTI can enable the emulation of multi-stage APT campaigns, but only when analyst-supplied parameters and assumptions are explicitly recorded. This, in turn, exposes the precise points at which current standards fail to support automation. Our results clarify the boundary between descriptive and machine-actionable CTI for adversary emulation.
Read the full abstract ▾
All authors Ágney Lopes Roth Ferraz, Sidnei Barbieri, Murray Evangelista de Souza, Lourenço Alves Pereira Júnior
Cryptography and Security
Towards Channel-Robust and Receiver-Independent Radio Frequency Fingerprint Identification
Jie Ma, Junqing Zhang, Guanxiong Shen et al. (+2 more)
Radio frequency fingerprint identification (RFFI) is an emerging method for authenticating Internet of Things (IoT) devices. RFFI exploits the intrinsic and unique hardware imperfections for classifying IoT devices. Deep learning-based RFFI has shown excellent performance. However, there are still remaining research challenges, such as limited public training
datasets as well as impacts of channel and receive effects. In this paper, we proposed a three-stage RFFI approach involving contrastive learning-enhanced pretraining, Siamese network-based classification network training, and inference. Specifically, we employed spectrogram as signal representation to decouple the transmitter impairments from channel effects and receiver impairments. We proposed an unsupervised contrastive learning method to pretrain a channel-robust RFF extractor. In addition, the Siamese network-based scheme is enhanced by data augmentation and contrastive loss, which is capable of jointly mitigating the effects of channel and receiver impairments. We carried out a comprehensive experimental evaluation using three public LoRa
datasets and one self-collected LoRa
dataset. The results demonstrated that our approach can effectively and simultaneously mitigate the effects of channel and receiver impairments. We also showed that pretraining can significantly reduce the required amount of the fine-tuning data. Our proposed approach achieved an accuracy of over 90% in dynamic non-line-of-sight (NLOS) scenarios when there are only 20 packets per device.
Read the full abstract ▾
All authors Jie Ma, Junqing Zhang, Guanxiong Shen, Linning Peng, Alan Marshall
Cryptography and Security
Rethinking Jailbreak Detection of Large Vision Language Models with Representational Contrastive Scoring
Peichun Hua, Hao Li, Shanghao Shi et al. (+2 more)
Large
Vision-
Language Models (LVLMs) are vulnerable to a growing array of
multimodal jailbreak attacks, necessitating defenses that are both generalizable to novel threats and efficient for practical deployment. Many current strategies fall short, either targeting specific attack patterns, which limits generalization, or imposing high computational overhead. While lightweight anomaly-detection methods offer a promising direction, we find that their common one-class design tends to confuse unseen benign inputs with malicious ones, leading to unreliable over-rejection. To address this, we propose Representational Contrastive Scoring (RCS), a framework built on a key insight: the most potent safety signals reside within the LVLM's own internal representations. Our approach inspects the internal geometry of these representations, learning a lightweight projection to maximally separate benign and malicious inputs in safety-critical layers. This enables a simple yet powerful contrastive score that differentiates true malicious intent from mere distribution shift. Our instantiations, MCD (Mahalanobis Contrastive Detection) and KCD (K-nearest Contrastive Detection), achieve state-of-the-art performance on a challenging evaluation protocol designed to test generalization to unseen attack types. This work demonstrates that effective jailbreak detection can be achieved by applying simple, interpretable statistical methods to the internal representations, offering a practical path towards safer LVLM deployment.
Read the full abstract ▾
All authors Peichun Hua, Hao Li, Shanghao Shi, Zhiyuan Yu, Ning Zhang
Cryptography and Security
Scalable IP Mimicry: End-to-End Deceptive IP Blending to Overcome Rectification and Scale Limitations of IP Camouflage
Junling Fan, George Rushevich, Giorgio Rusconi et al. (+3 more)
Semiconductor intellectual property (IP) theft incurs estimated annual losses ranging from $225 billion to $600 billion. Despite initiatives like the CHIPS Act, many
semiconductor designs remain vulnerable to reverse engineering (RE). IP Camouflage is a recent breakthrough that expands beyond the logic gate hiding of traditional camouflage through "mimetic deception," where an entire module masquerades as a different IP. However, it faces key limitations: requires a high-overhead post-generation rectification step, is not easily scalable, and uses an AIG logic representation that is mismatched with standard RE analysis flows. This paper addresses these shortcommings by introducing two novel, end-to-end models. We propose a Graph-Matching
algorithm to solve the representation problem and a DNAS-based NAND Array model to achieve scalability. To facilitate this, we also introduce a mimicry-aware partitioning method, enabling a divide-and-conquer approach for large-scale designs. Our results demonstrate that these models are resilient to SAT and GNN-RE attacks, providing efficient and scalable paths for end-to-end deceptive IP design.
Read the full abstract ▾
All authors Junling Fan, George Rushevich, Giorgio Rusconi, Mengdi Zhu, Reiner Dizon-Paradis, Domenic Forte
Cryptography and Security · Cross-listed from cs.SE
Model checking of hyperproperties for high-level relational models
Nuno Macedo and Hugo Pacheco
Many properties related to security or concurrency must be encoded as so-called hyperproperties, temporal properties that allow
reasoning about multiple traces of a system. However, despite recent advances on model checking hyperproperties, there is still a lack of higher-level specification
languages that can effectively support software engineering practitioners in verifying properties of this class at early stages of system design.
Alloy is a lightweight formal method with a high-level specification
language that is supported by automated analysis procedures, making it particularly well-suited for the verification of design models at early development stages. It does not natively support, however, the verification of hyperproperties. This work proposes HyperPardinus, a new model finding procedure that extends Pardinus – the temporal logic backend of the
Alloy language – to automatically verify hyperproperties over relational models by relying on existing low-level model checkers for hyperproperties. It then conservatively extends
Alloy to support the specification and automatic verification of hyperproperties over design models, as well as the visualization of (counter-)examples at a higher-level of abstraction. Evaluation shows that our approach enables modeling and finding (counter-)examples for complex hyperproperties with alternating quantifiers, making it feasible to address relevant scenarios from the state of the art.
Read the full abstract ▾
Cryptography and Security
MVP-ORAM: a Wait-free Concurrent ORAM for Confidential BFT Storage
Robin Vassantlal, Hasan Heydari, Bernardo Ferreira et al. (+1 more)
It is well known that encryption alone is not enough to protect data
privacy. Access patterns, revealed when operations are performed, can also be leveraged in inference attacks. Oblivious RAM (ORAM) hides access patterns by making client requests oblivious. However, existing protocols are still limited in supporting concurrent clients and Byzantine fault tolerance (BFT). We present MVP-ORAM, the first wait-free ORAM protocol that supports concurrent fail-prone clients. In contrast to previous works, MVP-ORAM avoids using trusted proxies, which require additional security assumptions, and concurrency control mechanisms based on inter-client communication or distributed locks, which limit overall throughput and the capability of tolerating faulty clients. Instead, MVP-ORAM enables clients to perform concurrent requests and merge conflicting updates as they happen, satisfying wait-freedom, i.e., clients make progress independently of the performance or failures of other clients. Since wait and collision freedom are fundamentally contradictory goals that cannot be achieved simultaneously in an asynchronous concurrent ORAM service, we define a weaker notion of obliviousness that depends on the application workload and number of concurrent clients, and prove MVP-ORAM is secure in practical scenarios where clients perform skewed block accesses. By being wait-free, MVP-ORAM can be seamlessly integrated into existing confidential BFT data stores, creating the first BFT ORAM construction. We implement MVP-ORAM on top of a confidential BFT data store and show our prototype can process hundreds of 4KB accesses per second in modern clouds.
Read the full abstract ▾
All authors Robin Vassantlal, Hasan Heydari, Bernardo Ferreira, Alysson Bessani
Cryptography and Security
Adversarial Attacks Against Deep Learning-Based Radio Frequency Fingerprint Identification
Jie Ma, Junqing Zhang, Guanxiong Shen et al. (+2 more)
Radio frequency fingerprint identification (RFFI) is an emerging technique for the lightweight authentication of wireless Internet of things (IoT) devices. RFFI exploits deep learning models to extract hardware impairments to uniquely identify wireless devices. Recent studies show deep learning-based RFFI is vulnerable to
adversarial attacks. However, effective
adversarial attacks against different types of RFFI classifiers have not yet been explored. In this paper, we carried out a comprehensive investigations into different
adversarial attack methods on RFFI systems using various deep learning models. Three specific
algorithms, fast gradient sign method (FGSM), projected gradient descent (PGD), and universal
adversarial perturbation (UAP), were analyzed. The attacks were launched to LoRa-RFFI and the experimental results showed the generated perturbations were effective against convolutional neural networks (CNNs), long short-term
memory (LSTM) networks, and gated recurrent units (GRU). We further used UAP to launch practical attacks. Special factors were considered for the wireless context, including implementing real-time attacks, the effectiveness of the attacks over a period of time, etc. Our experimental evaluation demonstrated that UAP can successfully launch
adversarial attacks against the RFFI, achieving a success rate of 81.7% when the adversary almost has no prior knowledge of the victim RFFI systems.
Read the full abstract ▾
All authors Jie Ma, Junqing Zhang, Guanxiong Shen, Alan Marshall, Chip-Hong Chang
Cryptography and Security
Super Suffixes: Bypassing Text Generation Alignment and Guard Models Simultaneously
Andrew Adiletta, Kathryn Adiletta, Kemal Derya et al. (+1 more)
The rapid deployment of Large
Language Models (LLMs) has created an urgent need for enhanced security and
privacy measures in Machine Learning (ML). LLMs are increasingly being used to process untrusted text inputs and even generate executable code, often while having access to sensitive system controls. To address these security concerns, several companies have introduced guard models, which are smaller, specialized models designed to protect text generation models from
adversarial or malicious inputs. In this work, we advance the study of
adversarial inputs by introducing Super Suffixes, suffixes capable of overriding multiple
alignment objectives across various models with different tokenization schemes. We demonstrate their effectiveness, along with our joint optimization technique, by successfully bypassing the protection mechanisms of Llama
Prompt Guard 2 on five different text generation models for malicious text and code generation. To the best of our knowledge, this is the first work to reveal that Llama
Prompt Guard 2 can be compromised through joint optimization. Additionally, by analyzing the changing similarity of a model's internal state to specific concept directions during
token sequence processing, we propose an effective and lightweight method to detect Super Suffix attacks. We show that the cosine similarity between the residual stream and certain concept directions serves as a distinctive fingerprint of model intent. Our proposed countermeasure, DeltaGuard, significantly improves the detection of malicious
prompts generated through Super Suffixes. It increases the non-benign classification rate to nearly 100%, making DeltaGuard a valuable addition to the guard model stack and enhancing robustness against
adversarial prompt attacks.
Read the full abstract ▾
All authors Andrew Adiletta, Kathryn Adiletta, Kemal Derya, Berk Sunar
Cryptography and Security · Cross-listed from cs.DC
Hypergraph based Multi-Party Payment Channel
Ayush Nainwal, Atharva Kamble and Nitin Awathare
Public blockchains inherently offer low throughput and high latency, motivating off-chain scalability solutions such as Payment Channel Networks (PCNs). However, existing PCNs suffer from liquidity fragmentation-funds locked in one channel cannot be reused elsewhere-and channel depletion, both of which limit routing efficiency and reduce transaction success rates. Multi-party channel (MPC) constructions mitigate these issues, but they typically rely on leaders or coordinators, creating single points of failure and providing only limited flexibility for inter-channel payments. We introduce Hypergraph-based Multi-Party Payment Channels (COALESCE), a new off-chain construction that replaces bilateral channels with collectively funded hyperedges. These hyperedges enable fully concurrent, leaderless intra- and inter-hyperedge payments through verifiable, proposer-ordered DAG updates, offering significantly greater flexibility and concurrency than prior designs. Hence our, design eliminates routing dependencies, avoids directional liquidity lock-up, and does not require central monitoring services such as watchtowers. Our implementation on a 150-node intra-hyperedge achieves a transaction success rate of approximately 94% under heavy load (larger payment sizes), while full hyperedge evaluation over a 15,000-node network sustains success rates in the range of 85% to 95%, without HTLC expiry or routing failures, highlighting the robustness of COALESCE.
Read the full abstract ▾
Cryptography and Security
SoK: Demystifying the multiverse of MPC protocols
Roberta De Viti, Vaastav Anand, Pierfrancesco Ingo et al. (+1 more)
This paper systematizes knowledge on the performance of Multi-Party Computation (MPC) protocols. Despite strong
privacy and correctness guarantees, MPC adoption in real-world applications remains limited by high costs (especially in the malicious setting) and lack of guidance on choosing suitable protocols for concrete workloads. We identify the theoretical and practical parameters that shape MPC efficiency and conduct an extensive experimental study across diverse
benchmarks. Our analysis discusses the trade-offs between protocols, and highlights which techniques align best with different application scenarios and needs. By providing actionable guidance for developers and outlining open challenges for researchers, this work seeks to narrow the gap between MPC theory and practice.
Read the full abstract ▾
All authors Roberta De Viti, Vaastav Anand, Pierfrancesco Ingo, Deepak Garg
Cryptography and Security
Leveraging FPGAs for Homomorphic Matrix-Vector Multiplication in Oblivious Message Retrieval
Grant Bosworth, Keewoo Lee and Sunwoong Kim
While end-to-end encryption protects the content of messages, it does not secure metadata, which exposes sender and receiver information through traffic analysis. A plausible approach to protecting this metadata is to have senders post encrypted messages on a public bulletin board and receivers scan it for relevant messages. Oblivious message
retrieval (OMR) leverages homomorphic encryption (HE) to improve user experience in this solution by delegating the scan to a resource-rich server while preserving
privacy. A key process in OMR is the homomorphic detection of pertinent messages for the receiver from the bulletin board. It relies on a specialized
matrix-vector multiplication
algorithm, which involves extensive multiplications between ciphertext vectors and plaintext
matrices, as well as homomorphic rotations. The computationally intensive nature of this process limits the practicality of OMR. To address this challenge, this paper proposes a hardware architecture to accelerate the
matrix-vector multiplication
algorithm. The building homomorphic operators in this
algorithm are implemented using high-level synthesis, with design parameters for different parallelism levels. These operators are then deployed on a field-programmable gate array platform using an efficient design space exploration strategy to accelerate homomorphic
matrix-vector multiplication. Compared to a software implementation, the proposed hardware accelerator achieves a 13.86x speedup.
Read the full abstract ▾
Cryptography and Security
Granite: Granular Runtime Enforcement for GitHub Actions Permissions
Mojtaba Moazen, Amir.M Ahmadian and Musard Balliu
Modern software projects use automated CI/CD pipelines to streamline their development, build, and deployment processes. GitHub Actions is a popular CI/CD platform that enables project maintainers to create custom workflows – collections of jobs composed of sequential steps – using reusable components known as actions. Wary of the security risks introduced by fully-privileged actions, GitHub provides a job-level permission model for controlling workflow access to repository resources. Unfortunately, this model is too coarse-grained to reduce the attack surface pertaining to permission misuse attacks: All actions within a job share the same permissions granted to the job. This violates the principle of least privilege and can lead to broader software supply chain attacks, whenever a compromised action exploits the granted permissions to compromise the repository resources. In this paper, we present Granite, a runtime proxy-based system that enforces fine-grained permissions for GitHub Actions at the step-level granularity within a job. Granite transparently monitors requests made by JavaScript and composite actions during workflow execution and checks them against predefined step-level policies at runtime. We evaluate Granite in terms of compatibility, security, and performance overhead using a
dataset of 500 workflows comprising 12,916 jobs from the most-starred GitHub repositories that use GitHub Actions. Our analysis reveals that 52.7% of the jobs can be protected by Granite against permission misuse attacks. We evaluate Granite on 20 top-starred repositories (63 actions, 58 workflows), validate attack prevention using 10 permission misuse attacks across 42 overprivileged jobs, and measure an average overhead of 55% (3.67 seconds) per job, concluding that Granite effectively reduces CI/CD attack surfaces.
Read the full abstract ▾
Cryptography and Security
Capacitive Touchscreens at Risk: Recovering Handwritten Trajectory on Smartphone via Electromagnetic Emanations
Yukun Cheng, Shiyu Zhu, Changhai Ou et al. (+3 more)
This paper reveals and exploits a critical security vulnerability: the electromagnetic (EM) side channel of capacitive touchscreens leaks sufficient information to recover fine-grained, continuous handwriting trajectories. We present Touchscreen Electromagnetic Side-channel Leakage Attack (TESLA), a non-contact attack framework that captures EM signals generated during on-screen writing and regresses them into two-dimensional (2D) handwriting trajectories in real time. Extensive evaluations across a variety of commercial off-the-shelf (COTS) smartphones show that TESLA achieves 77% character recognition accuracy and a Jaccard index of 0.74, demonstrating its capability to recover highly recognizable motion trajectories that closely resemble the original handwriting under realistic attack conditions.
Read the full abstract ▾
All authors Yukun Cheng, Shiyu Zhu, Changhai Ou, Xingshuo Han, Yuan Li, Shihui Zheng
Cryptography and Security · Cross-listed from cs.SE
Towards Privacy-Preserving Code Generation: Differentially Private Code Language Models
Melih Catal, Pooja Rani and Harald C. Gall
Large
language models specialized for code (CodeLLMs) have demonstrated remarkable capabilities in generating code snippets, documentation, and test cases. However, despite their promising capabilities, CodeLLMs can inadvertently memorize and reproduce snippets from their training data, which poses risks of
privacy breaches and intellectual property violations. These risks restrict the deployment of CodeLLMs in sensitive domains and limit their training
datasets to publicly available sources. To mitigate the memorization risk without compromising their task performance, we apply Differential
Privacy (DP) to CodeLLMs. To the best of our knowledge, this is the first comprehensive study that systematically evaluates the effectiveness of DP in CodeLLMs. DP adds calibrated noise to the training process to protect individual data points while still allowing the model to learn useful patterns. To this end, we first identify and understand the driving reasons of the memorization behaviour of the CodeLLMs during their fine-tuning. Then, to address this issue, we empirically evaluate the effect of DP on mitigating memorization while preserving code generation capabilities. Our findings show that DP substantially reduces memorization in CodeLLMs across all the tested snippet types. The snippet types most prone to memorization are also the most effectively mitigated by DP. Furthermore, we observe that DP slightly increases perplexity but preserves, and can even enhance, the code generation capabilities of CodeLLMs, which makes it feasible to apply DP in practice without significantly compromising model utility. Finally, we analyze the impact of DP on training efficiency and energy consumption, finding that DP does not significantly affect training time or energy usage, making it a practical choice for
privacy-preserving CodeLLMs training.
Read the full abstract ▾
Cryptography and Security
Proving DNSSEC Correctness: A Formal Approach to Secure Domain Name Resolution
Qifan Zhang, Zilin Shen, Imtiaz Karim et al. (+2 more)
The Domain Name System Security Extensions (DNSSEC) are critical for preventing DNS spoofing, yet its specifications contain ambiguities and vulnerabilities that elude traditional "break-and-fix" approaches. A holistic, foundational security analysis of the protocol has thus remained an open problem. This paper introduces DNSSECVerif, the first framework for comprehensive, automated formal security analysis of the DNSSEC protocol suite. Built on the SAPIC+ symbolic verifier, our high-fidelity model captures protocol-level interactions, including cryptographic operations and stateful caching with fine-grained concurrency control. Using DNSSECVerif, we formally prove four of DNSSEC's core security guarantees and uncover critical ambiguities in the standards–notably, the insecure coexistence of NSEC and NSEC3. Our model also automatically rediscovers three classes of known attacks, demonstrating fundamental weaknesses in the protocol design. To bridge the model-to-reality gap, we validate our findings through targeted testing of mainstream DNS software and a large-scale measurement study of over 2.2 million open resolvers, confirming the real-world impact of these flaws. Our work provides crucial, evidence-based recommendations for hardening DNSSEC specifications and implementations.
Read the full abstract ▾
All authors Qifan Zhang, Zilin Shen, Imtiaz Karim, Elisa Bertino, Zhou Li
Cryptography and Security
Visualisation for the CIS benchmark scanning results
Zhenshuo Zhao, Maria Spichkova, Duttkumari Champavat et al. (+4 more)
In this paper, we introduce GraphSecure, a web application that provides advanced analysis and visualisation of security scanning results. GraphSecure enables users to initiate scans for their AWS account, validate them against specific Center for Internet Security (CIS)
Benchmarks and return results, showcase those returned results in the form of statistical charts and warn the users about their account status.
Read the full abstract ▾
All authors Zhenshuo Zhao, Maria Spichkova, Duttkumari Champavat, Juilee N. Kulkarni, Sahil Singla, Muhammad A. Zulkefli, Pradhuman Khandelwal
Cryptography and Security · Cross-listed from quant-ph
A Survey of OAM-Encoded High-Dimensional Quantum Key Distribution: Foundations, Experiments, and Recent Trends
Huan Zhang, Zhenyu Cao, Yu Sun et al. (+1 more)
High-dimensional
quantum key distribution (HD-QKD) enhances information efficiency and noise tolerance by encoding data in large
Hilbert spaces. The orbital angular momentum (OAM) of light provides a scalable basis for such encoding and supports high-dimensional photonic communication. Practical OAM-based implementations remain constrained by challenges in state generation, transmission, and detection. This survey offers a consolidated overview of OAM-encoded HD-QKD, outlining fundamental principles, representative experiments, and system-level limitations. Recent progress in hybrid encodings, mode sorting, adaptive optics, and TF, CV, MDI, and DI frameworks is summarized with emphasis on practical feasibility.
Read the full abstract ▾
All authors Huan Zhang, Zhenyu Cao, Yu Sun, Hu Jin
Cryptography and Security
Vision-Based Learning for Cyberattack Detection in Blockchain Smart Contracts and Transactions
Do Hai Son, Le Vu Hieu, Tran Viet Khoa et al. (+5 more)
Blockchain technology has experienced rapid growth and has been widely adopted across various sectors, including healthcare, finance, and energy. However, blockchain platforms remain vulnerable to a broad range of cyberattacks, particularly those aimed at exploiting transactions and smart contracts (SCs) to steal digital assets or compromise system integrity. To address this issue, we propose a novel and effective framework for detecting cyberattacks within blockchain systems. Our framework begins with a preprocessing tool that uses Natural
Language Processing (NLP) techniques to transform key features of blockchain transactions into image representations. These images are then analyzed through
vision-based analysis using
Vision Transformers (ViT), a recent advancement in computer
vision known for its superior ability to capture complex patterns and semantic relationships. By integrating NLP-based preprocessing with
vision-based learning, our framework can detect a wide variety of attack types. Experimental evaluations on
benchmark datasets demonstrate that our approach significantly outperforms existing state-of-the-art methods in terms of both accuracy (achieving 99.5%) and robustness in cyberattack detection for blockchain transactions and SCs.
Read the full abstract ▾
All authors Do Hai Son, Le Vu Hieu, Tran Viet Khoa, Yibeltal F. Alem, Hoang Trong Minh, Tran Thi Thuy Quynh, Nguyen Viet Ha, Nguyen Linh Trung
Cryptography and Security
Cerium: A Multi-GPU Framework for Terabyte-Scale Encrypted Inference
Siddharth Jayashankar, Joshua Kim, Michael B. Sullivan et al. (+2 more)
Encrypted AI using fully homomorphic encryption (FHE) enables inference directly over encrypted queries, providing strong
privacy guarantees. However, its computational and
memory overheads have limited practical deployment. Custom FHE accelerators improve performance, but rely on advanced manufacturing technologies that limit their accessibility. GPUs offer a more widely available alternative, yet achieving ASIC-class performance on GPUs is challenging. Large models such as LLMs compound these challenges by requiring optimized kernels, terabyte-scale
memory management, and efficient execution across multiple devices. We present Cerium, a multi-GPU framework for large-scale FHE inference. Cerium combines a domain-specific
language, an optimizing compiler, and a runtime system to automatically generate optimized GPU kernels, compress plaintext data, manage terabyte-scale
memory footprints, and optimize multi-GPU communication. Implemented on NVIDIA GPUs, Cerium outperforms expert-written GPU libraries by up to 2.25x and achieves performance competitive with state-of-the-art FHE ASICs, matching the CraterLake ASIC. It is the first GPU system to execute CKKS bootstrapping in under 10 milliseconds, achieving 7.5 milliseconds, and is the first to demonstrate encrypted inference for BERT-Base and Llama3-8B prefill in 8 seconds and 43 seconds, respectively. The Cerium framework is open-source and available at https://github.com/CMU-CAOS/Cerium
Read the full abstract ▾
All authors Siddharth Jayashankar, Joshua Kim, Michael B. Sullivan, Wenting Zheng, Dimitrios Skarlatos