This paper investigates control synthesis for motion planning under conditions of uncertainty,specifically in robot motion and environmental properties,which are modeled using a probabilistic labeled Markov decision p...This paper investigates control synthesis for motion planning under conditions of uncertainty,specifically in robot motion and environmental properties,which are modeled using a probabilistic labeled Markov decision process(PL-MDP).To address this,a model-free reinforcement learning(RL)approach is designed to produce a finite-memory control policy that meets complex tasks specified by linear temporal logic(LTL)formulas.Recognizing the presence of uncertainties and potentially conflicting objectives,this study centers on addressing infeasible LTL specifications.A relaxed LTL constraint enables the agent to adapt its motion plan,allowing for partial satisfaction by accounting for necessary task violations.Additionally,a new automaton structure is introduced to increase the density of accepting rewards,facilitating deterministic policy outcomes.The proposed RL framework is rigorously analyzed and prioritizes two key objectives:(1)satisfying the acceptance condition of the relaxed product MDP,and(2)minimizing long-term violation costs.Simulation and experimental results are presented to demonstrate the framework’s effectiveness and robustness.展开更多
High quality software requirement specification is crucial for a software development. Although much efforts and research works have been done to address the problem, the errors in user requirement are still prevent u...High quality software requirement specification is crucial for a software development. Although much efforts and research works have been done to address the problem, the errors in user requirement are still prevent us from developing high quality software. To address the problem, this paper proposes integrating graphical specification technique UML with formal specification technique to construct user requirement specification. We also present a prototype tool to perform the automatic translation from UML specification into Object-Z specification.展开更多
Privilege user is needed to manage the commercial transactions, but a super-administrator may have monopolize power and cause serious security problem. Relied on trusted computing technology, a privilege separation me...Privilege user is needed to manage the commercial transactions, but a super-administrator may have monopolize power and cause serious security problem. Relied on trusted computing technology, a privilege separation method is proposed to satisfy the security management requirement for information systems. It authorizes the system privilege to three different managers, and none of it can be interfered by others. Process algebra Communication Sequential Processes is used to model the three powers mechanism, and safety effect is analyzed and compared.展开更多
The development of algebraic and numerical algorithms is a kind of complicated creative work and it is difficult to guarantee the correctness of the algorithms. This paper introduces a systematic and unified formal de...The development of algebraic and numerical algorithms is a kind of complicated creative work and it is difficult to guarantee the correctness of the algorithms. This paper introduces a systematic and unified formal development method of algebraic and numerical algorithms. The method implements the complete refinement process from abstract specifications to a concrete executable program. It uses the core idea of partition and recursion for formal derivation and combines the mathematical induction based on strict mathematical logic with Hoare axiom for correctness verification. This development method converts creative work into non-creative work as much as possible while ensuring the correctness of the algorithm, which can not only verify the correctness of the existing algebraic and numerical algorithms but also guide the development of efficient unknown algorithms for such problems. This paper takes the non-recursive implementation of the Extended Euclidean Algorithm and Horner's method as examples. Therefore, the effectiveness and feasibility of this method are further verified.展开更多
Since communication protocol deals with complex issues related to distribution such as communication, concurrency and synchronization, their development needs to be traced by using sophisticated formal description met...Since communication protocol deals with complex issues related to distribution such as communication, concurrency and synchronization, their development needs to be traced by using sophisticated formal description methods. This paper presents a new hybrid formal method for communication protocol specification. In this method, finite state machine (FSM), communication sequential process (CSP) and abstract data type (ADT) are mixed and the best features of these approaches are offered. In this paper, the main formal description techniques (FDT) for protocol engineering are brieny introduced and a hybrid formal description method based on the FSM, CSP and ADT for communication protocol is described. Finally, this paper presents the formal specification of an example protocol for LAN by using the proposed hybrid formal method. The results of studies show that the hybrid formal description method for communication protocol is an available and effective approach.展开更多
Linear temporal logic(LTL)is an intuitive and expressive language to specify complex control tasks,and how to design an efficient control strategy for LTL specification is still a challenge.In this paper,we implement ...Linear temporal logic(LTL)is an intuitive and expressive language to specify complex control tasks,and how to design an efficient control strategy for LTL specification is still a challenge.In this paper,we implement the dynamic quantization technique to propose a novel hierarchical control strategy for nonlinear control systems under LTL specifications.Based on the regions of interest involved in the LTL formula,an accepting path is derived first to provide a high-level solution for the controller synthesis problem.Second,we develop a dynamic quantization based approach to verify the realization of the accepting path.The realization verification results in the necessity of the controller design and a sequence of quantization regions for the controller design.Third,the techniques of dynamic quantization and abstraction-based control are combined together to establish the local-to-global control strategy.Both abstraction construction and controller design are local and dynamic,thereby resulting in the potential reduction of the computational complexity.Since each quantization region can be considered locally and individually,the proposed hierarchical mechanism is more efficient and can solve much larger problems than many existing methods.Finally,the proposed control strategy is illustrated via two examples from the path planning and tracking problems of mobile robots.展开更多
Based on the authentication tests and the strand space model, the robust email protocol with perfect forward secrecy is formally analyzed, and the security shortcomings of the protocol is pointed out. Meanwhile, the m...Based on the authentication tests and the strand space model, the robust email protocol with perfect forward secrecy is formally analyzed, and the security shortcomings of the protocol is pointed out. Meanwhile, the man-in-the-middle attack to the protocol is given, where the attacker forges the messages in the receiving phase to cheat the two communication parties and makes them share the wrong session keys with him. Therefore, the protocol is not ensured to provide perfect forward secrecy. In order to overcome the above security shortcomings, an advanced email protocol is proposed, where the corresponding signatures in the receiving phase of the protocol are added to overcome the man-in-the-middle attack and ensure to provide perfect forward secrecy. Finally, the proposed advanced email protocol is formally analyzed with the authentication tests and the strand space model, and it is proved to be secure in authentication of the email sender, the recipient and the server. Therefore, the proposed advanced email protocol can really provide perfect forward secrecy.展开更多
In this paper,w e provide a novel scheme to solve the motion planning problem of multi-agent systems under high-level task specifications.First,linear temporal logic is applied to express the global task specification...In this paper,w e provide a novel scheme to solve the motion planning problem of multi-agent systems under high-level task specifications.First,linear temporal logic is applied to express the global task specification.Then an efficient and decentralized algorithm is proposed to decom pose it into local tasks.M oreover,w e use control barrier function to synthesize the local controller for each agent under the linear temporal logic motion plan with safety constraint.Finally,simulation results show the effectiveness and efficiency of our proposed scheme.展开更多
In this paper,a formal system is proposed based on beta reputation for the development of trustworthy wireless sensor networks(FRS-TWSN).Following this approach,key concepts related to reputation are formal described ...In this paper,a formal system is proposed based on beta reputation for the development of trustworthy wireless sensor networks(FRS-TWSN).Following this approach,key concepts related to reputation are formal described step by step for wireless sensor networks where sensor nodes maintain reputation for other sensors and use it to evaluate their trustworthiness.By proving some properties of beta reputation system,the beta distribution is founded to fit well to describe reputation system.Also,a case system is developed within this framework for reputation representation,updates and integration.Simulation results show this scheme not only can keep stable reputation but also can prevent the system from some attacks as bad mouthing and reputation cheating.展开更多
We present a model based on Computational Temporal Logic(CTL)methods forverifying security requirements of electronic commerce,protocols.The model describes formally theauthentication,confidentiality integrity,non-rep...We present a model based on Computational Temporal Logic(CTL)methods forverifying security requirements of electronic commerce,protocols.The model describes formally theauthentication,confidentiality integrity,non-repudiation denial of serviee and access control ofthe e-lectronic commerce protocols.We illustrate as case study a variant of the Lu-Smolka protocolproposed by Lu-Smolka Moreover,we have discovered two attacks that allow a dishonest user topurchase a good debiting the amountto another user.And also,we compared our work with relativeresearch works and found lhat the formal way of this paper is more general to specify securityprotocols for E-Commerce.展开更多
There were various conventional modeling techniques with varied semantics for system reliability assessment, such as fault trees(FT), Markov process(MP), and Petri nets. However, it is strenuous to construct and to ma...There were various conventional modeling techniques with varied semantics for system reliability assessment, such as fault trees(FT), Markov process(MP), and Petri nets. However, it is strenuous to construct and to maintain models utilizing these formalisms throughout the life cycle of system under development. This paper proposes a unified formal modeling language to build a general reliability model. The method eliminates the gap between the actual system and reliability model and shows details of the system clearly. Furthermore,the model could be transformed into FT and MP through specific rules defined by a formal language to assess system-level reliability.展开更多
Cloud computing systems play a vital role in national security. This paper describes a conceptual framework called dualsystem architecture for protecting computing environments. While attempting to be logical and rigo...Cloud computing systems play a vital role in national security. This paper describes a conceptual framework called dualsystem architecture for protecting computing environments. While attempting to be logical and rigorous, formalism method is avoided and this paper chooses algebra Communication Sequential Process.展开更多
With the vigorous development of blockchain technology represented by</span><span style="font-family:""> Bitcoin, blockchain technology has gradually surpassed the era of programmable curren...With the vigorous development of blockchain technology represented by</span><span style="font-family:""> Bitcoin, blockchain technology has gradually surpassed the era of programmable currency and entered the era of smart contracts. Smart contracts are event-</span><span style="font-family:""> </span><span style="font-family:"">driven and stateful. With the in-depth development of blockchain technology, smart contracts use protocols and user interfaces to complete all steps of the contract process, allowing users to implement personalized code logic on the blockchain. Contract technology has the characteristics of decentralization, autonomy, observability, verifiability, and information sharing. It can effectively build programmable finance and programmable society, and is widely <span>used in digital payment, financial asset disposal, multi-signature contracts,</span> cloud computing, Internet of Things, sharing economy and other fields. First, it ex<span>plains the basic concepts, full life cycle, basic classification, basic structure, </span>key <span>technologies, development status and main technology platforms of smart</span> contracts;then discusses the application scenarios and development issues of smart contract technology, aiming to provide smart contract technology</span><span style="font-family:"">.</span><span style="font-family:""> The research and development provides reference.展开更多
Formal methods use mathematical models to develop systems.Ontologies are formal specifications that provide reusable domain knowledge representations.Ontologies have been successfully used in several data-driven appli...Formal methods use mathematical models to develop systems.Ontologies are formal specifications that provide reusable domain knowledge representations.Ontologies have been successfully used in several data-driven applications,including data analysis.However,the creation of formal models from informal requirements demands skill and effort.Ambiguity,inconsistency,imprecision,and incompleteness are major problems in informal requirements.To solve these problems,it is necessary to have methods and approaches for supporting the mapping of requirements to formal specifications.The purpose of this paper is to present an approach that addresses this challenge by using theWeb Ontology Language(OWL)to construct Event-B formal models and support data analysis.Our approach reduces the burden of working with the formal notations of OWL ontologies and Event-B models and aims to analyze domain knowledge and construct Event-B models from OWL ontologies using visual diagrams.The idea is based on the transformation of OntoGraf diagrams of OWL ontologies to UML-B diagrams for the purpose of bridging the gap between OWL ontologies and Event-B models.Visual data exploration assists with both data analysis and the development of Event-B formal models.To manage complexity,Event-B supports stepwise refinement to allow each requirement to be introduced at themost appropriate stage in the development process.UML-B supports refinement,so we also introduce an approach that allows us to divide and layer OntoGraf diagrams.展开更多
The prerequisite for the existing protocols' correctness is that protocols can be normally operated under the normal conditions, rather than dealing with abnormal conditions. In other words, protocols with the fau...The prerequisite for the existing protocols' correctness is that protocols can be normally operated under the normal conditions, rather than dealing with abnormal conditions. In other words, protocols with the fault-tolerance can not be provided when some fault occurs. This paper discusses the self fault-tolerance of protocols. It describes some concepts and methods for achieving self fault-tolerance of protocols. Meanwhile, it provides a case study, investigates a typical protocol that does not satisfy the self fault-tolerance, and gives a new redesign version of this existing protocol using the proposed approach.展开更多
Moving-target-defense(MTD)fundamentally avoids an illegal initial compromise by asymmetrically increasing the uncertainty as the attack surface of the observable defender changes depending on spatial-temporal mutation...Moving-target-defense(MTD)fundamentally avoids an illegal initial compromise by asymmetrically increasing the uncertainty as the attack surface of the observable defender changes depending on spatial-temporal mutations.However,the existing naive MTD studies were conducted focusing only on wired network mutations.And these cases have also been no formal research on wireless aircraft domains with attributes that are extremely unfavorable to embedded system operations,such as hostility,mobility,and dependency.Therefore,to solve these conceptual limitations,this study proposes normalized drone-type MTD that maximizes defender superiority by mutating the unique fingerprints of wireless drones and that optimizes the period-based mutation principle to adaptively secure the sustainability of drone operations.In addition,this study also specifies MF2-DMTD(model-checkingbased formal framework for drone-type MTD),a formal framework that adopts model-checking and zero-sum game,for attack-defense simulation and performance evaluation of drone-type MTD.Subsequently,by applying the proposed models,the optimization of deceptive defense performance of drone-type MTD for each mutation period also additionally achieves through mixed-integer quadratic constrained programming(MIQCP)and multiobjective optimization-based Pareto frontier.As a result,the optimal mutation cycles in drone-type MTD were derived as(65,120,85)for each control-mobility,telecommunication,and payload component configured inside the drone.And the optimal MTD cycles for each swarming cluster,ground control station(GCS),and zone service provider(ZSP)deployed outside the drone were also additionally calculated as(70,60,85),respectively.To the best of these authors’knowledge,this study is the first to calculate the deceptive efficiency and functional continuity of the MTD against drones and to normalize the trade-off according to a sensitivity analysis with the optimum.展开更多
This paper proposes a formal method which is used to model and analyze network devices such as touters. It is based on an algebraic process called “ACSR-VP”, which enhances the original CCS algebraic process by inco...This paper proposes a formal method which is used to model and analyze network devices such as touters. It is based on an algebraic process called “ACSR-VP”, which enhances the original CCS algebraic process by incorporating the notions of time, resource requirements, dynamic prioritization, and synchronization. Therefore, although there are many formal methods to analyze the timed concurrency system, ACSR-VP, due to its prominent features, is best fit for analysis of a resource bounded real-time system. This paper extends ACSR-VP to EACSR-VP, which is more adaptive to the features of network devices and specializes in analyzing this kind of embedded system. EACSR-VP adds the notion of n-way communication which allows more than two processes to participate in synchronization. It also enhances value-passing capabilities which make for more flexible specifications. Finally, specifications, verification and analysis methods with EACSR-VP are introduced by a case study of router with multiple input queues.展开更多
The short-range wireless communication technology has advanced considerably and provides the feasibility of train-train(T2T)communication link in the communication-based train control system.The introduction of the T2...The short-range wireless communication technology has advanced considerably and provides the feasibility of train-train(T2T)communication link in the communication-based train control system.The introduction of the T2T link would reduce the headway and improve operational efficiency.Formal methods are system design techniques that use rigorously specified mathematical models to ensure all behaviors work as expected.And it is exactly the functional safety verification needed.Therefore,to deal with the functional safety verification of the T2T link,an untimed colored petri net model is first constructed.Secondly,the verification process is performed.Conclusions can be drawn from the state space report and the computation tree logic queries.Lastly,the model is parameterized,and then data log files are obtained for further performance measurement.Results show that the proposed criteria are satisfied and there are no defects in the basic design requirements.The transmission delay has considered the reconnection,transmission errors and the interruption.The probability of the delay lower than 150 ms accounts for 98.106%,which meets the specification and the previous field test.展开更多
This paper elaborated on the limitation of authentication test theorem, illustrated the fundamental cause of that limitation through examples, then enhanced authentication test to solve this problem, and also proved t...This paper elaborated on the limitation of authentication test theorem, illustrated the fundamental cause of that limitation through examples, then enhanced authentication test to solve this problem, and also proved the soundness of that improvement with formal method. The enhanced theory can deal with protocols with test component as proper subterm of other regular node＇ s component under certain conditions, and extend the application scope of authentication test. With enhanced authentication test, the automatic protocol verification tools will be more efficient and convenient.展开更多
A set of generalized symmetries with arbitrary functions of t for the Konopelchenko-Dubrovsky (KD)equation in 2+1 space dimensions is given by using a direct method called formal function series method presented by Lo...A set of generalized symmetries with arbitrary functions of t for the Konopelchenko-Dubrovsky (KD)equation in 2+1 space dimensions is given by using a direct method called formal function series method presented by Lou. These symmetries constitute an infinite-dimensional generalized w∞ algebra.展开更多
基金supported by the National Natural Science Foundation of China under Grant 62173314.
文摘This paper investigates control synthesis for motion planning under conditions of uncertainty,specifically in robot motion and environmental properties,which are modeled using a probabilistic labeled Markov decision process(PL-MDP).To address this,a model-free reinforcement learning(RL)approach is designed to produce a finite-memory control policy that meets complex tasks specified by linear temporal logic(LTL)formulas.Recognizing the presence of uncertainties and potentially conflicting objectives,this study centers on addressing infeasible LTL specifications.A relaxed LTL constraint enables the agent to adapt its motion plan,allowing for partial satisfaction by accounting for necessary task violations.Additionally,a new automaton structure is introduced to increase the density of accepting rewards,facilitating deterministic policy outcomes.The proposed RL framework is rigorously analyzed and prioritizes two key objectives:(1)satisfying the acceptance condition of the relaxed product MDP,and(2)minimizing long-term violation costs.Simulation and experimental results are presented to demonstrate the framework’s effectiveness and robustness.
文摘High quality software requirement specification is crucial for a software development. Although much efforts and research works have been done to address the problem, the errors in user requirement are still prevent us from developing high quality software. To address the problem, this paper proposes integrating graphical specification technique UML with formal specification technique to construct user requirement specification. We also present a prototype tool to perform the automatic translation from UML specification into Object-Z specification.
文摘Privilege user is needed to manage the commercial transactions, but a super-administrator may have monopolize power and cause serious security problem. Relied on trusted computing technology, a privilege separation method is proposed to satisfy the security management requirement for information systems. It authorizes the system privilege to three different managers, and none of it can be interfered by others. Process algebra Communication Sequential Processes is used to model the three powers mechanism, and safety effect is analyzed and compared.
基金Supported by the National Natural Science Foundation of China (61862033, 61762049, 61902162)Jiangxi Provincial Natural Science Foundation (20202BABL202026, 20202BABL202025, 20202BAB202015)。
文摘The development of algebraic and numerical algorithms is a kind of complicated creative work and it is difficult to guarantee the correctness of the algorithms. This paper introduces a systematic and unified formal development method of algebraic and numerical algorithms. The method implements the complete refinement process from abstract specifications to a concrete executable program. It uses the core idea of partition and recursion for formal derivation and combines the mathematical induction based on strict mathematical logic with Hoare axiom for correctness verification. This development method converts creative work into non-creative work as much as possible while ensuring the correctness of the algorithm, which can not only verify the correctness of the existing algebraic and numerical algorithms but also guide the development of efficient unknown algorithms for such problems. This paper takes the non-recursive implementation of the Extended Euclidean Algorithm and Horner's method as examples. Therefore, the effectiveness and feasibility of this method are further verified.
文摘Since communication protocol deals with complex issues related to distribution such as communication, concurrency and synchronization, their development needs to be traced by using sophisticated formal description methods. This paper presents a new hybrid formal method for communication protocol specification. In this method, finite state machine (FSM), communication sequential process (CSP) and abstract data type (ADT) are mixed and the best features of these approaches are offered. In this paper, the main formal description techniques (FDT) for protocol engineering are brieny introduced and a hybrid formal description method based on the FSM, CSP and ADT for communication protocol is described. Finally, this paper presents the formal specification of an example protocol for LAN by using the proposed hybrid formal method. The results of studies show that the hybrid formal description method for communication protocol is an available and effective approach.
基金supported by the Fundamental Research Funds for the Central Universities(DUT22RT(3)090)the National Natural Science Foundation of China(61890920,61890921,62122016,08120003)Liaoning Science and Technology Program(2023JH2/101700361).
文摘Linear temporal logic(LTL)is an intuitive and expressive language to specify complex control tasks,and how to design an efficient control strategy for LTL specification is still a challenge.In this paper,we implement the dynamic quantization technique to propose a novel hierarchical control strategy for nonlinear control systems under LTL specifications.Based on the regions of interest involved in the LTL formula,an accepting path is derived first to provide a high-level solution for the controller synthesis problem.Second,we develop a dynamic quantization based approach to verify the realization of the accepting path.The realization verification results in the necessity of the controller design and a sequence of quantization regions for the controller design.Third,the techniques of dynamic quantization and abstraction-based control are combined together to establish the local-to-global control strategy.Both abstraction construction and controller design are local and dynamic,thereby resulting in the potential reduction of the computational complexity.Since each quantization region can be considered locally and individually,the proposed hierarchical mechanism is more efficient and can solve much larger problems than many existing methods.Finally,the proposed control strategy is illustrated via two examples from the path planning and tracking problems of mobile robots.
基金The Natural Science Foundation of Jiangsu Province(No.BK2006108)
文摘Based on the authentication tests and the strand space model, the robust email protocol with perfect forward secrecy is formally analyzed, and the security shortcomings of the protocol is pointed out. Meanwhile, the man-in-the-middle attack to the protocol is given, where the attacker forges the messages in the receiving phase to cheat the two communication parties and makes them share the wrong session keys with him. Therefore, the protocol is not ensured to provide perfect forward secrecy. In order to overcome the above security shortcomings, an advanced email protocol is proposed, where the corresponding signatures in the receiving phase of the protocol are added to overcome the man-in-the-middle attack and ensure to provide perfect forward secrecy. Finally, the proposed advanced email protocol is formally analyzed with the authentication tests and the strand space model, and it is proved to be secure in authentication of the email sender, the recipient and the server. Therefore, the proposed advanced email protocol can really provide perfect forward secrecy.
基金This work was partially supported by the National Natural Science Foundation of China(No.51475334)the National Key Research and Development Program of Science and Technology of China(No.2018YFB1305304)the Shanghai Science and Technology Pilot Project(No.19511132100).
文摘In this paper,w e provide a novel scheme to solve the motion planning problem of multi-agent systems under high-level task specifications.First,linear temporal logic is applied to express the global task specification.Then an efficient and decentralized algorithm is proposed to decom pose it into local tasks.M oreover,w e use control barrier function to synthesize the local controller for each agent under the linear temporal logic motion plan with safety constraint.Finally,simulation results show the effectiveness and efficiency of our proposed scheme.
基金the National Natural Science Foundation of China(60573043)the Natural Science Foundation of Guangdong Province(06025838)
文摘In this paper,a formal system is proposed based on beta reputation for the development of trustworthy wireless sensor networks(FRS-TWSN).Following this approach,key concepts related to reputation are formal described step by step for wireless sensor networks where sensor nodes maintain reputation for other sensors and use it to evaluate their trustworthiness.By proving some properties of beta reputation system,the beta distribution is founded to fit well to describe reputation system.Also,a case system is developed within this framework for reputation representation,updates and integration.Simulation results show this scheme not only can keep stable reputation but also can prevent the system from some attacks as bad mouthing and reputation cheating.
基金Supported by the Natural Science Foundation ofthe Department of Education of Guangdong Province(Z03001)
文摘We present a model based on Computational Temporal Logic(CTL)methods forverifying security requirements of electronic commerce,protocols.The model describes formally theauthentication,confidentiality integrity,non-repudiation denial of serviee and access control ofthe e-lectronic commerce protocols.We illustrate as case study a variant of the Lu-Smolka protocolproposed by Lu-Smolka Moreover,we have discovered two attacks that allow a dishonest user topurchase a good debiting the amountto another user.And also,we compared our work with relativeresearch works and found lhat the formal way of this paper is more general to specify securityprotocols for E-Commerce.
文摘There were various conventional modeling techniques with varied semantics for system reliability assessment, such as fault trees(FT), Markov process(MP), and Petri nets. However, it is strenuous to construct and to maintain models utilizing these formalisms throughout the life cycle of system under development. This paper proposes a unified formal modeling language to build a general reliability model. The method eliminates the gap between the actual system and reliability model and shows details of the system clearly. Furthermore,the model could be transformed into FT and MP through specific rules defined by a formal language to assess system-level reliability.
文摘Cloud computing systems play a vital role in national security. This paper describes a conceptual framework called dualsystem architecture for protecting computing environments. While attempting to be logical and rigorous, formalism method is avoided and this paper chooses algebra Communication Sequential Process.
文摘With the vigorous development of blockchain technology represented by</span><span style="font-family:""> Bitcoin, blockchain technology has gradually surpassed the era of programmable currency and entered the era of smart contracts. Smart contracts are event-</span><span style="font-family:""> </span><span style="font-family:"">driven and stateful. With the in-depth development of blockchain technology, smart contracts use protocols and user interfaces to complete all steps of the contract process, allowing users to implement personalized code logic on the blockchain. Contract technology has the characteristics of decentralization, autonomy, observability, verifiability, and information sharing. It can effectively build programmable finance and programmable society, and is widely <span>used in digital payment, financial asset disposal, multi-signature contracts,</span> cloud computing, Internet of Things, sharing economy and other fields. First, it ex<span>plains the basic concepts, full life cycle, basic classification, basic structure, </span>key <span>technologies, development status and main technology platforms of smart</span> contracts;then discusses the application scenarios and development issues of smart contract technology, aiming to provide smart contract technology</span><span style="font-family:"">.</span><span style="font-family:""> The research and development provides reference.
基金This work was supported by Taif University Researchers Supporting Project Number(TURSP-2020/292),Taif University,Taif,Saudi Arabia.
文摘Formal methods use mathematical models to develop systems.Ontologies are formal specifications that provide reusable domain knowledge representations.Ontologies have been successfully used in several data-driven applications,including data analysis.However,the creation of formal models from informal requirements demands skill and effort.Ambiguity,inconsistency,imprecision,and incompleteness are major problems in informal requirements.To solve these problems,it is necessary to have methods and approaches for supporting the mapping of requirements to formal specifications.The purpose of this paper is to present an approach that addresses this challenge by using theWeb Ontology Language(OWL)to construct Event-B formal models and support data analysis.Our approach reduces the burden of working with the formal notations of OWL ontologies and Event-B models and aims to analyze domain knowledge and construct Event-B models from OWL ontologies using visual diagrams.The idea is based on the transformation of OntoGraf diagrams of OWL ontologies to UML-B diagrams for the purpose of bridging the gap between OWL ontologies and Event-B models.Visual data exploration assists with both data analysis and the development of Event-B formal models.To manage complexity,Event-B supports stepwise refinement to allow each requirement to be introduced at themost appropriate stage in the development process.UML-B supports refinement,so we also introduce an approach that allows us to divide and layer OntoGraf diagrams.
基金This project was supported by the National Natural Science Foundation of China and the Natural Science Foundation of Hubei Prov
文摘The prerequisite for the existing protocols' correctness is that protocols can be normally operated under the normal conditions, rather than dealing with abnormal conditions. In other words, protocols with the fault-tolerance can not be provided when some fault occurs. This paper discusses the self fault-tolerance of protocols. It describes some concepts and methods for achieving self fault-tolerance of protocols. Meanwhile, it provides a case study, investigates a typical protocol that does not satisfy the self fault-tolerance, and gives a new redesign version of this existing protocol using the proposed approach.
基金funding by the Challengeable Future Defense Technology Research and Development Program through the Agency For Defense Development(ADD)funded by the Defense Acquisition Program Administration(DAPA)in 2023(No.915024201).
文摘Moving-target-defense(MTD)fundamentally avoids an illegal initial compromise by asymmetrically increasing the uncertainty as the attack surface of the observable defender changes depending on spatial-temporal mutations.However,the existing naive MTD studies were conducted focusing only on wired network mutations.And these cases have also been no formal research on wireless aircraft domains with attributes that are extremely unfavorable to embedded system operations,such as hostility,mobility,and dependency.Therefore,to solve these conceptual limitations,this study proposes normalized drone-type MTD that maximizes defender superiority by mutating the unique fingerprints of wireless drones and that optimizes the period-based mutation principle to adaptively secure the sustainability of drone operations.In addition,this study also specifies MF2-DMTD(model-checkingbased formal framework for drone-type MTD),a formal framework that adopts model-checking and zero-sum game,for attack-defense simulation and performance evaluation of drone-type MTD.Subsequently,by applying the proposed models,the optimization of deceptive defense performance of drone-type MTD for each mutation period also additionally achieves through mixed-integer quadratic constrained programming(MIQCP)and multiobjective optimization-based Pareto frontier.As a result,the optimal mutation cycles in drone-type MTD were derived as(65,120,85)for each control-mobility,telecommunication,and payload component configured inside the drone.And the optimal MTD cycles for each swarming cluster,ground control station(GCS),and zone service provider(ZSP)deployed outside the drone were also additionally calculated as(70,60,85),respectively.To the best of these authors’knowledge,this study is the first to calculate the deceptive efficiency and functional continuity of the MTD against drones and to normalize the trade-off according to a sensitivity analysis with the optimum.
文摘This paper proposes a formal method which is used to model and analyze network devices such as touters. It is based on an algebraic process called “ACSR-VP”, which enhances the original CCS algebraic process by incorporating the notions of time, resource requirements, dynamic prioritization, and synchronization. Therefore, although there are many formal methods to analyze the timed concurrency system, ACSR-VP, due to its prominent features, is best fit for analysis of a resource bounded real-time system. This paper extends ACSR-VP to EACSR-VP, which is more adaptive to the features of network devices and specializes in analyzing this kind of embedded system. EACSR-VP adds the notion of n-way communication which allows more than two processes to participate in synchronization. It also enhances value-passing capabilities which make for more flexible specifications. Finally, specifications, verification and analysis methods with EACSR-VP are introduced by a case study of router with multiple input queues.
基金National Natural Science Foundation of China(No.61963023)。
文摘The short-range wireless communication technology has advanced considerably and provides the feasibility of train-train(T2T)communication link in the communication-based train control system.The introduction of the T2T link would reduce the headway and improve operational efficiency.Formal methods are system design techniques that use rigorously specified mathematical models to ensure all behaviors work as expected.And it is exactly the functional safety verification needed.Therefore,to deal with the functional safety verification of the T2T link,an untimed colored petri net model is first constructed.Secondly,the verification process is performed.Conclusions can be drawn from the state space report and the computation tree logic queries.Lastly,the model is parameterized,and then data log files are obtained for further performance measurement.Results show that the proposed criteria are satisfied and there are no defects in the basic design requirements.The transmission delay has considered the reconnection,transmission errors and the interruption.The probability of the delay lower than 150 ms accounts for 98.106%,which meets the specification and the previous field test.
基金the National High Technology Research and Development Programme of China(No.863-104-03-01)
文摘This paper elaborated on the limitation of authentication test theorem, illustrated the fundamental cause of that limitation through examples, then enhanced authentication test to solve this problem, and also proved the soundness of that improvement with formal method. The enhanced theory can deal with protocols with test component as proper subterm of other regular node＇ s component under certain conditions, and extend the application scope of authentication test. With enhanced authentication test, the automatic protocol verification tools will be more efficient and convenient.
基金浙江省自然科学基金，浙江省宁波市博士基金，the State Key Laboratory of Oil/Gas Reservoir Geology and Exploitation，Scientific Research Fund of Education Department of Zhejiang Province under
文摘A set of generalized symmetries with arbitrary functions of t for the Konopelchenko-Dubrovsky (KD)equation in 2+1 space dimensions is given by using a direct method called formal function series method presented by Lou. These symmetries constitute an infinite-dimensional generalized w∞ algebra.
