Achieving a balance between interoperability and security in blockchain systems has led to the development of various integration mechanisms. These include the use of specialized smart contracts to facilitate cross-chain interactions, enabling reliable connections and secure transfers of information and assets. While technical interoperability is effectively addressed at lower layers, achieving semantic interoperability at the application layer remains a significant challenge. This paper proposes a mechanism to address this challenge by leveraging a model-driven approach. Metamodels, models, and transformations are created, and smart contracts are defined abstractly and then semi-automatically generated for specific blockchain platforms. The proposed approach was validated by generating contracts between Ethereum and Hyperledger, enabling semantically compatible transactions. The mechanism was further evaluated using the Technology Acceptance Model with expert participants. This evaluation demonstrated its effectiveness in specifying and transforming contracts and fostering semantic interoperability across blockchains.

As quantum computers advance, the complexity of the software they can execute increases as well. To ensure this software is efficient, maintainable, reusable, and cost-effective—key qualities of any industry-grade software—mature software engineering practices must be applied throughout its design, development, and operation. However, the significant differences between classical and quantum software make it challenging to directly apply classical software engineering methods to quantum systems. This challenge has led to the emergence of Quantum Software Engineering (QSE) as a distinct field within the broader software engineering landscape. In this work, a group of active researchers analyze in depth the current state of QSE research. From this analysis, the key areas of QSE are identified and explored in order to determine the most relevant open challenges that should be addressed in the next years. These challenges help identify necessary breakthroughs and future research directions for advancing QSE.

Progress in the realm of quantum technologies is paving the way for a multitude of potential applications across different sectors. However, the reduced number of available quantum computers, their technical limitations, and the high demand for their use are posing some problems for developers and researchers. Mainly, users trying to execute quantum circuits on these devices are usually facing long waiting times in the task queues. In this context, this work proposes a Service-Oriented architecture to reduce waiting times and optimize quantum computer usage by scheduling the circuits from different users into combined circuits that are executed at the same time. To validate this proposal, different widely known quantum algorithms have been selected and executed in combined circuits. The obtained results are then compared with the results of executing the same algorithms in an isolated way. This allowed us to measure the impact of the use of the scheduler against quantum noise. Among the obtained results, it has been possible to verify that the noise suffered by executing a combination of circuits through the proposed scheduler does not critically affect the outcomes.

Quantum computing plays a crucial role in solving complex problems for which classical supercomputers require an impractical amount of time. This emerging paradigm has the potential to revolutionize various fields such as cryptography, chemistry, and finance, making it a highly relevant area of research and development. Major companies such as Google, Amazon, IBM, and Microsoft, along with prestigious research institutions such as Oxford and MIT, are investing significant efforts into advancing this technology. However, the lack of a standardized approach among different providers poses challenges for developers to effectively access and utilize quantum computing resources. In this study, we propose a quantum orchestrator that is designed to facilitate the orchestration and execution of quantum circuits across multiple quantum service providers. The proposed solution aims to simplify the process for developers and facilitate the execution of quantum tasks using resources offered by different providers. The proposal is validated with the implementation of the proposed orchestrator for Amazon Braket and IBM Quantum. It can support both quantum and classical developers in defining, configuring, and executing circuits independently of the selected provider.

Abstract Early advances in quantum computing have provided new opportunities to tackle intricate problems in diverse areas such as cryptography, optimization, and simulation. However, current methodologies employed in quantum computing often require, among other things, a broad understanding of quantum hardware and low‐level programming languages, posing challenges to software developers in effectively creating and implementing quantum services. This study advocates the adoption of software engineering principles in quantum computing, thereby establishing a higher level of hardware abstraction that allows developers to focus on application development. With this proposal, developers can design and deploy quantum services with less effort, which is similar to the facilitation provided by service‐oriented computing for the development of conventional software services. This study introduces a continuous deployment strategy adapted to the development of quantum services that covers the creation and deployment of such services. For this purpose, an extension of the OpenAPI specification is proposed, which allows the generation of services that implement quantum algorithms. The proposal was validated through the creation of an application programming interface with diverse quantum algorithm implementations and evaluated through a survey of various developers and students who were introduced to the tool with positive results.

Abstract After decades of advances, mainly theoretical, in recent years quantum computing has begun to show its first practical applications. This new and revolutionary technology aims to enhance essential areas such as cybersecurity, financial services, or medicine. The growth of this technology has encouraged different research centers and big companies such as IBM, Amazon, and Google to dedicate considerable efforts to developing new technologies that bring quantum computing to the market. However, these technologies are not yet mature and create a significant vendor lock-in problem. Therefore, new tools are needed that facilitate access to this technology and that allow developers to increase the abstraction level at which they work. Given that the integration of quantum software should not be very different from that of classical services, we can take advantage of the knowledge acquired and use current techniques of service-oriented computing. In this work, we have carried out a technical comparison between different quantum computing service providers using a case study, by performing empirical tests based on the Travelling Salesman Problem. This study highlights the differences between the main providers. To address these differences and reduce the vendor lock-in effect, we propose an extension of the Quantum API Gateway to support the different providers and the casuistry that each one presents. This would allow programmers to deploy quantum code without vendor-specific knowledge of the major providers, which would facilitate access and simplify the development of quantum applications.

The rapid advancements in quantum computing have opened new possibilities for solving complex problems in various fields, including cryptography, optimization, and simulation. However, the current approaches to quantum computing often require a deep understanding of quantum hardware and low-level programming languages, making it difficult for software developers to create and deploy quantum services. This paper argues for the adaptation of Service-Oriented Computing principles to quantum computing, enabling a level of abstraction from hardware that allows developers to focus on application development. This will allow developers to create and deploy quantum services, similarly to how Service-Oriented Computing has made it easier to develop traditional software services. This paper presents a Continuous Deployment approach for quantum service development, which involves the generation and deployment of quantum services. To do that, we propose an extension of the OpenAPI specification to generate services implementing a quantum algorithm. To validate the feasibility of the proposed process, we use a variety of quantum algorithm implementations to test their generation and deployment of quantum services.

Abstract The development that quantum computing technologies are achieving is beginning to attract the interest of companies that could potentially be users of quantum software. Thus, it is perfectly feasible that during the next few years hybrid systems will start to appear integrating both the classical software systems of companies and new quantum ones providing solutions to problems that still remain unmanageable today. A natural way to support such integration is Service-Oriented Computing. While conceptually the invocation of a quantum software service is similar to that of a classical one, technically there are many differences and technological limitations, which refer to platform independence, decoupling, scalability, etc. To highlight these differences and the difficulties to develop quality quantum services, this paper takes a well-known problem to which a quantum solution can be provided, integer factorization, making use of the Amazon Braket quantum service platform. The exercise of trying to provide the factorization as a quantum service is carried out following the best practices, design patterns and standards existing in the implementation of classical services. This case study is used to highlight the rough edges and limitations that arise in the integration of classical-quantum hybrid systems using service-oriented computing. The conclusion of the study allows us to point out directions in which to focus research efforts in order to achieve effective quantum service-oriented computing.

The rate of world population aging is increasing. This situation directly affects all countries socially and economically, increasing their compromise and effort to improve the living conditions of this sector of society. In environments with large influxes of elderly people, such as nursing homes, the use of technology has shown promise in improving their quality of life. The use of smart devices allows people to automate everyday tasks and learn from them to predict future actions. Additionally, smartphones capture a wealth of information that allows to adapt to nearby actuators according to people’s preferences and even detects anomalies in their behaviour. Current works are proposing new frameworks to detect these behaviours and act accordingly. However, these works are not focused on managing multidevice environments where sensor and smartphone data are considered to automate environments with elderly people or to learn from them. Also, most of these works require a permanent Internet connection, so the full benefit of smart devices is not completely achieved. In this work, we present an architecture that takes the data from sensors and smartphones in order to adapt the behaviour of the actuators of the environment. In addition, it uses this data to learn from the environment to predict actions or to extrapolate the actions that should be executed according to similar behaviours. The architecture is implemented through a use case based on a nursing home located in a rural area. Thanks to this work, the quality of life of the elderly is improved in a simple, affordable, and transparent way for them.