As quantum computing continues to emerge, ensuring the quality of quantum programs has become increasingly critical. Quantum program testing has emerged as a prominent research area within the scope of quantum software engineering. While numerous approaches have been proposed to address quantum program quality assurance, our analysis reveals that most existing methods rely on measurement-based validation in practice. However, due to the inherently probabilistic nature of quantum programs, measurement-based validation methods face significant limitations.To investigate these limitations, we conducted an empirical study of recent research on quantum program testing, analyzing measurement-based validation methods in the literature. Our analysis categorizes existing measurement-based validation methods into two groups: distribution-level validation and output-value-level validation. We then compare measurement-based validation with statevector-based validation methods to evaluate their pros and cons. Our findings demonstrate that measurement-based validation is suitable for straightforward assessments, such as verifying the existence of specific output values, while statevector-based validation proves more effective for complicated tasks such as assessing the program behaviors.

With the continual escalation of cyberattack tactics, zero-day exploits and advanced persistent threats (APTs) characterized by high stealth and dynamic evolution have posed significant challenges to traditional honeypot systems. Existing approaches are limited in service fidelity, interactive intelligence, and awareness of attacker intent, making it difficult to effectively lure advanced attackers or reconstruct threat chains from massive volumes of log data. To address these challenges, this paper introduces large language models (LLMs) as the core driving force to construct an architecture that integrates log-driven data governance with dynamic response generation. Leveraging the semantic understanding and generative capabilities of LLMs, the proposed method enables fine-grained identification of attacker intent, reconstruction of event sequences, and adaptive responses driven by retrieval-augmented generation (RAG), thereby realizing an intelligent closed-loop defense. This innovative integration overcomes the constraints of traditional static rules and low interaction emulation, achieving attack intent analysis and adaptive deception response, and providing an efficient pathway for proactive threat hunting. During a 25day deployment in a real production network environment, the system utilized 25 diversion nodes and 8 types of emulated services to capture over 1.39 million raw attack logs. Analysis revealed multiple attack attempts targeting 9 known Common Vulnerabilities and Exposures (CVE) vulnerabilities, along with a substantial number of high-severity attacks for which specific CVE identifiers could not be determined. Experimental results demonstrate that the proposed approach significantly improves both the accuracy of threat awareness and the timeliness of response, providing reliable support for the evolution of intelligent defense mechanisms.

Deep neural networks (DNNs) have been widely adopted in many decision-making industrial applications. Their fairness issues, i.e., whether there exist unintended biases in the DNN, receive much attention and become critical concerns, which can directly cause negative impacts in our daily life and potentially undermine the fairness of our society, especially with their increasing deployment at an unprecedented speed. Recently, some early attempts have been made to provide fairness assurance of DNNs, such as fairness testing, which aims at finding discriminatory samples empirically, and fairness certification, which develops sound but not complete analysis to certify the fairness of DNNs. Nevertheless, how to formally compute discriminatory samples and fairness scores (i.e., the percentage of fair input space), is still largely uninvestigated. In this paper, we propose DeepGemini, a novel fairness formal analysis technique for DNNs, which contains two key components: discriminatory sample discovery and fairness score computation. To uncover discriminatory samples, we encode the fairness of DNNs as safety properties and search for discriminatory samples by means of state-of-the-art verification techniques for DNNs. This reduction enables us to be the first to formally compute discriminatory samples. To compute the fairness score, we develop counterexample guided fairness analysis, which utilizes four heuristics to efficiently approximate a lower bound of fairness score. Extensive experimental evaluations demonstrate the effectiveness and efficiency of DeepGemini on commonly-used benchmarks, and DeepGemini outperforms state-of-the-art DNN fairness certification approaches in terms of both efficiency and scalability.

Deep neural networks are widely used in image classification tasks, but their internal decision-making mechanisms are often difficult to explain. While various algorithms have been developed to visualize these mechanisms, many of them produce coarse, noisy results that are not always convincing. To address this issue, we propose a method for enhancing saliency maps produced by saliency methods. Our method uses a fixed-size sliding window to upsample local regions of the input image and feed them into the selected visualization algorithm to generate class-specific saliency maps and probability scores. We then downsample the resulting saliency maps and multiply them by the probability scores to obtain maps with greater detail. We evaluate our method using different saliency methods and network architectures, and demonstrate its effectiveness through both quantitative metrics and intuitive evaluation. Our results show that our method significantly improves the performance of these saliency methods, providing a more valid and reliable means of visualizing the decision mechanisms of deep neural networks. Code is available at https://github.com/LuoLogic/Enhuncement-saliency.

The visualization of deep learning models has been widely studied as an effective means of exploring the decision-making processes within these models. However, current visualization methods suffer from several limitations, such as low resolution and poor visualization of multiple occurrences of the same class. In this paper, we propose a novel visualization technique called MSG-CAM, which is an improvement on the existing Group-CAM method. Our method uses the feature maps and gradients of the last layer of the convolutional neural network to create masks through multi-scale enlargement of the original input image and fusion of the resulting feature maps and gradients. Through both qualitative and quantitative analysis, we have demonstrated that the saliency maps generated by our method are more reasonable and accurately reflect the internal decision-making processes of the neural network.

The reliability of decision-making policies is urgently important today as they have established the fundamentals of many critical applications, such as autonomous driving and robotics. To ensure reliability, there have been a number of research efforts on testing decision-making policies that solve Markov decision processes (MDPs). However, due to the deep neural network (DNN)-based inherit and infinite state space, developing scalable and effective testing frameworks for decision-making policies still remains open and challenging. In this paper, we present an effective testing framework for decision-making policies. The framework adopts a generative diffusion model-based test case generator that can easily adapt to different search spaces, ensuring the practicality and validity of test cases. Then, we propose a termination state novelty-based guidance to diversify agent behaviors and improve the test effectiveness. Finally, we evaluate the framework on five widely used benchmarks, including autonomous driving, aircraft collision avoidance, and gaming scenarios. The results demonstrate that our approach identifies more diverse and influential failure-triggering test cases compared to current state-of-the-art techniques. Moreover, we employ the detected failure cases to repair the evaluated models, achieving better robustness enhancement compared to the baseline method.

The recent fast development of quantum computers breaks several computation limitations that are difficult for conventional computers. Up to the present, although many approaches and tools have been proposed to test quantum programs, the fundamental features of quantum programs, i.e., magnitude, phase, and entanglement, have been largely overlooked, leading to limited fault detection capability and reduced testing effectiveness. To address this problem, we propose an automated testing framework named QURATEST, equipped with three test case generators (including two newly proposed techniques, UCNOT and IQFT in this paper, as well as one based on Random techniques) to test quantum programs. Overall, the proposed generators enable the generation of diverse test inputs by considering the quantum features of quantum programs. In the experiments, we perform an in-depth evaluation of QURATEST from three aspects: generated test case diversity, output coverage of the program under test, and fault detection capability. The results demonstrate the potential of our newly proposed techniques in that IQFT can generate the most diverse test cases regarding magnitude, phase, and entanglement, with 66% cell coverage. Comparatively, the Random approach only has 10% cell coverage. Regarding the evaluations of the output coverage, IQFT can achieve the highest output coverage in 70.2% (33 out of 47) of all quantum programs. In terms of fault detection, UCNOT outperforms the other two techniques. Specifically, the test cases generated by UCNOT have the best mutation score in 88.4% (23 out of 26) quantum programs.

Deep neural networks (DNNs) achieved a significant performance breakthrough over the past decade and have been widely adopted in various industrial domains. However, a fundamental problem regarding DNN robustness is still not adequately addressed, which can potentially lead to many quality issues after deployment, e.g., safety, security, and reliability. An adversarial attack is one of the most commonly investigated techniques to penetrate a DNN by misleading the DNN’s decision through the generation of minor perturbations in the original inputs. More importantly, the adversarial attack is a crucial way to assess, estimate, and understand the robustness boundary of a DNN. Intuitively, a stronger adversarial attack can help obtain a tighter robustness boundary, allowing us to understand the potential worst-case scenario when a DNN is deployed. To push this further, in this paper, we propose DeepRover, a fuzzing-based blackbox attack for deep neural networks used for image classification. We show that DeepRover is more effective and query-efficient in generating adversarial examples than state-of-the-art blackbox attacks. Moreover, DeepRover can find adversarial examples at a finer-grained level than other approaches.

Over the past few years, deep neural networks (DNNs) have achieved tremendous success and have been continuously applied in many application domains. However, during the practical deployment in industrial tasks, DNNs are found to be erroneous-prone due to various reasons such as overfitting and lacking of robustness to real-world corruptions during practical usage. To address these challenges, many recent attempts have been made to repair DNNs for version updates under practical operational contexts by updating weights (i.e., network parameters) through retraining, fine-tuning, or direct weight fixing at a neural level. Nevertheless, existing solutions often neglect the effects of neural network architecture and weight relationships across neurons and layers. In this work, as the first attempt, we initiate to repair DNNs by jointly optimizing the architecture and weights at a higher (i.e., block level). We first perform empirical studies to investigate the limitation of whole network-level and layer-level repairing, which motivates us to explore a novel repairing direction for DNN repair at the block level. To this end, we need to further consider techniques to address two key technical challenges, i.e., block localization , where we should localize the targeted block that we need to fix; and how to perform joint architecture and weight repairing . Specifically, we first propose adversarial-aware spectrum analysis for vulnerable block localization that considers the neurons’ status and weights’ gradients in blocks during the forward and backward processes, which enables more accurate candidate block localization for repairing even under a few examples. Then, we further propose the architecture-oriented search-based repairing that relaxes the targeted block to a continuous repairing search space at higher deep feature levels. By jointly optimizing the architecture and weights in that space, we can identify a much better block architecture. We implement our proposed repairing techniques as a tool, named ArchRepair , and conduct extensive experiments to validate the proposed method. The results show that our method can not only repair but also enhance accuracy and robustness, outperforming the state-of-the-art DNN repair techniques.

Formal methods use SMT solvers extensively for deciding formula satisfiability, for instance, in software verification, systematic test generation, and program synthesis. However, due to their complex implementations, solvers may contain critical bugs that lead to unsound results. Given the wide applicability of solvers in software reliability, relying on such unsound results may have detrimental consequences. In this paper, we present STORM, a novel blackbox mutational fuzzing technique for detecting critical bugs in SMT solvers. We run our fuzzer on seven mature solvers and find 29 previously unknown critical bugs. STORM is already being used in testing new features of popular solvers before deployment.

Although deep neural networks have been very successful in image-classification tasks, they are prone to adversarial attacks. To generate adversarial inputs, there has emerged a wide variety of techniques, such as black- and whitebox attacks for neural networks. In this paper, we present DeepSearch, a novel fuzzing-based, query-efficient, blackbox attack for image classifiers. Despite its simplicity, DeepSearch is shown to be more effective in finding adversarial inputs than state-of-the-art blackbox approaches. DeepSearch is additionally able to generate the most subtle adversarial inputs in comparison to these approaches.

Recently, there is growing concern that machine-learned software, which currently assists or even automates decision making, reproduces, and in the worst case reinforces, bias present in the training data. The development of tools and techniques for certifying fairness of this software or describing its biases is, therefore, critical. In this paper, we propose a perfectly parallel static analysis for certifying fairness of feed-forward neural networks used for classification of tabular data. When certification succeeds, our approach provides definite guarantees, otherwise, it describes and quantifies the biased input space regions. We design the analysis to be sound, in practice also exact, and configurable in terms of scalability and precision, thereby enabling pay-as-you-go certification. We implement our approach in an open-source tool called Libra and demonstrate its effectiveness on neural networks trained on popular datasets.

Software Model Checking (SMC) is a well-known automatic program verification technique and frequently adopted for checking safety-critical software. Thus, the reliability of SMC tools themselves (i.e., software model checkers) is critical. However, little work exists on validating software model checkers, an important problem that this paper tackles by introducing a practical, automated fuzzing technique. For its simplicity and generality, we focus on control-flow reachability (e.g., whether or how many times a branch is reached) and address two specific challenges for effective fuzzing: oracle and scalability. Given a deterministic program, we (1) leverage its concrete executions to synthesize valid branch reachability properties (thus solving the oracle problem) and (2) fuse such individual properties into a single safety property (thus improving the scalability of fuzzing and reducing manual inspection). We have realized our approach as the MCFuzz tool and applied it to extensively test three state-of-the-art C software model checkers, CPAchecker, CBMC, and SeaHorn. MCFuzz has found 62 unique bugs in all three model checkers -- 58 have been confirmed, and 20 have been fixed. We have further analyzed and categorized these bugs (which are diverse), and summarized several lessons for building reliable and robust model checkers. Our testing effort has been well-appreciated by the model checker developers, and also led to improved tool usability and documentation.

Assurance of information-flow security by formal methods is mandated in security certification of separation kernels. As an industrial standard for improving safety, ARINC 653 has been complied with by mainstream separation kernels. Due to the new trend of integrating safe and secure functionalities into one separation kernel, security analysis of ARINC 653 as well as a formal specification with security proofs are thus significant for the development and certification of ARINC 653 compliant Separation Kernels (ARINC SKs). This paper presents a specification development and security analysis method for ARINC SKs based on refinement. We propose a generic security model and a stepwise refinement framework. Two levels of functional specification are developed by the refinement. A major part of separation kernel requirements in ARINC 653 are modeled, such as kernel initialization, two-level scheduling, partition and process management, and inter-partition communication. The formal specification and its security proofs are carried out in the Isabelle/HOL theorem prover. We have reviewed the source code of one industrial and two open-source ARINC SK implementations, i.e., VxWorks 653, XtratuM, and POK, in accordance with the formal specification. During the verification and code review, six security flaws, which can cause information leakage, are found in the ARINC 653 standard and the implementations.

Deep learning (DL) defines a new data-driven programming paradigm where the internal system logic is largely shaped by the training data. The standard way of evaluating DL models is to examine their performance on a test dataset. The quality of the test dataset is of great importance to gain confidence of the trained models. Using an inadequate test dataset, DL models that have achieved high test accuracy may still lack generality and robustness. In traditional software testing, mutation testing is a well-established technique for quality evaluation of test suites, which analyzes to what extent a test suite detects the injected faults. However, due to the fundamental difference between traditional software and deep learning-based software, traditional mutation testing techniques cannot be directly applied to DL systems. In this paper, we propose a mutation testing framework specialized for DL systems to measure the quality of test data. To do this, by sharing the same spirit of mutation testing in traditional software, we first define a set of source-level mutation operators to inject faults to the source of DL (i.e., training data and training programs). Then we design a set of model-level mutation operators that directly inject faults into DL models without a training process. Eventually, the quality of test data could be evaluated from the analysis on to what extent the injected faults could be detected. The usefulness of the proposed mutation testing techniques is demonstrated on two public datasets, namely MNIST and CIFAR-10, with three DL models.

Deep learning (DL) defines a new data-driven programming paradigm that constructs the internal system logic of a crafted neuron network through a set of training data. We have seen wide adoption of DL in many safety-critical scenarios. However, a plethora of studies have shown that the state-of-the-art DL systems suffer from various vulnerabilities which can lead to severe consequences when applied to real-world applications. Currently, the testing adequacy of a DL system is usually measured by the accuracy of test data. Considering the limitation of accessible high quality test data, good accuracy performance on test data can hardly provide confidence to the testing adequacy and generality of DL systems. Unlike traditional software systems that have clear and controllable logic and functionality, the lack of interpretability in a DL system makes system analysis and defect detection difficult, which could potentially hinder its real-world deployment. In this paper, we propose DeepGauge, a set of multi-granularity testing criteria for DL systems, which aims at rendering a multi-faceted portrayal of the testbed. The in-depth evaluation of our proposed testing criteria is demonstrated on two well-known datasets, five DL systems, and with four state-of-the-art adversarial attack techniques against DL. The potential usefulness of DeepGauge sheds light on the construction of more generic and robust DL systems.

Partitioning operating systems (POSs) have been widely applied in safety-critical domains from aerospace to automotive. In order to improve the safety and the certification process of POSs, the ARINC 653 standard has been developed and complied with by the mainstream POSs. Rigorous formalization of ARINC 653 can reveal hidden errors in this standard and provide a necessary foundation for formal verification of POSs and ARINC 653 applications. For the purpose of reusability and efficiency, a novel methodology by integrating ontology and refinement is proposed to formally specify and analyze POSs in this paper. An ontology of POSs is developed as an intermediate model between informal descriptions of ARINC 653 and the formal specification in Event-B. A semiautomatic translation from the ontology and ARINC 653 into Event-B is implemented, which leads to a complete Event-B specification for ARINC 653 compliant POSs. During the formal analysis, six hidden errors in ARINC 653 have been discovered and fixed in the Event-B specification. We also validate the existence of these errors in two open-source POSs, i.e., XtratuM and POK. By introducing the ontology, the degree of automatic verification of the Event-B specification reaches a higher level.

A secure routing infrastructure is vital for secure and reliable Internet services. Source authentication and path validation are two fundamental primitives for building a more secure and reliable Internet. Although several protocols have been proposed to implement these primitives, they have not been formally analyzed for their security guarantees. In this paper, we apply proof techniques for verifying cryptographic protocols (e.g., key exchange protocols) to analyzing network protocols. We encode LS2, a program logic for reasoning about programs that execute in an adversarial environment, in Coq. We also encode protocol-specific data structures, predicates, and axioms. To analyze a source-routing protocol that uses chained MACs to provide origin and path validation, we construct Coq proofs to show that the protocol satisfies its desired properties. To the best of our knowledge, we are the first to formalize origin and path authenticity properties, and mechanize proofs that chained MACs can provide the desired authenticity properties.