Zero-knowledge proofs (zkp) have been used to address several blockchain limitations (e.g. privacy, scalability). Recent work has proposed its usage to improve blockchain interoperability solutions, aiming to help software architects and developers reduce barriers to blockchain adoption. However, more studies are needed to understand the full potential of zkp in this context. In this paper, we empirically analyse how zkp may improve a gateway-based solution for blockchain interoperability. The results showed that it was possible to improve the selected solution in terms of privacy and data confidentiality limitations, by incorporating anonymous cross-chain authentication and private data exchange. A prototype was developed and evaluated using three strategies: 1) its application in a use case scenario, 2) performance tests, and 3) cost analysis. The evaluation showed that the approach is technically feasible, but not suitable for every use case. Furthermore, the private data exchange approach confirmed the results of other studies: zkp is not mature enough for some scenarios, and more work is required in this area.

Distributed ledger technologies (DLT) usage is currently limited to a single platform as they do not have design-based interoperability capabilities. In general, it's challenging for a DLT to communicate with another one. Although several DLT solutions have been proposed and applied in specific application areas, building a general-purpose interoperability solution for any DLT remains a challenge. In previous work, we proposed a tailor-made interoperability solution between Hyperledger Fabric and Corda. This paper extends that work to enable interoperability between Hyperledger Fabric and Ethereum. The main contribution of this paper is to provide a new approach to enable interoperability between these two DLT. The approach follows a new request-response interaction model and future payments to enable the payments of services. A prototype was developed and evaluated through a case scenario, performance tests and cost analysis. Performance tests showed bottlenecks under heavy load scenarios due to Ethereum's design. Costs analysis showed that the approach is suitable for purchasing high-priced services. These promising results constitute a step forward in developing a general-purpose solution for DLT interoperability.

During the last years, interoperability has become one of the main challenges within blockchain research as blockchains increasingly require integration between each other. Indeed, blockchains work by design in silos of information as interoperability is not a native feature. The main efforts in the field target permissionless blockchains, such as Bitcoin and Ethereum. However, interoperability in permissioned blockchains remains as an almost untouched area of work as they introduce additional requirements focusing on privacy and identity. Although there are some interoperability solutions for permissioned blockchains, they are either high-level design proposals not providing concrete implementations or focus on interoperability issues between business applications and blockchain platforms. In this paper we propose a gateway-based platform-to-platform interoperability solution for permissioned blockchains, which comprises a detailed solution design and a reference implementation. The proposal was assessed through the development of a social security case scenario, based on the reference implementation and using two blockchain platforms: Hyperledger Fabric and Corda.

Since the beginning of 2020, COVID-19 has had a strong impact on the health of the world population. Tracing the contacts of infected people is one of the main strategies for controlling the pandemic. Given the high rates of contagion, which makes difficult an effective manual tracing, multiple initiatives arose for developing digital proximity tracing technologies. In this paper, we discuss in depth the security and personal data protection requirements that these technologies must satisfy, and we present an exhaustive and detailed list of the various applications that have been deployed globally. In particular, we identify potential threats that could undermine the satisfaction of the analyzed requirements, violating hegemonic personal data protection regulations.

The daily operation of organizations leaves a trail of the execution of business processes (BPs) including activities, events and decisions taken by participants. Compliance requirements add specific control elements to process execution, e.g. domain and/or country regulations to be fulfilled, enforcing order of interaction messages or activities, or security checks on roles and permissions. As the amount of available data in organizations grows everyday, using execution data to detect compliance violations and its causes, can help organizations to take corrective actions for improving their processes and comply to applying rules. Compliance requirements violations can be detected at runtime to prevent further execution, or in a post mortem way using Process Mining to evaluate process execution data against the specified compliance requirements for the process. In this paper we present a BP compliance Requirements Model (BPCRM) defining generic compliance controls that can be used to specify specific compliance requirements over BPs, that are used as input to assess compliance violations with process mining. This model can be seen as a catalogue that includes a set of predefined compliance rules or patterns in one place, helping organizations to specify and evaluate the compliance of their processes.

The development of large-scale software systems is usually supported by integration platforms, which provide connectivity and mediation capabilities to facilitate the integration of heterogeneous and distributed applications. Integration platforms have traditionally been built as monolithic systems which, in some of the current contexts (e.g. market's high pace of demand, large amount of users and data), present issues in terms of scalability, maintainability and fault tolerance, among others. In turn, microservices architecture is an approach for developing applications as a set of small independent services, which may contribute to address such limitations (e.g. maintaining and scaling services independently, according to their specific needs). Indeed, various integration platform proposals leveraging this approach have emerged during the last years. However, those proposals are domain-specific and/or they do not provide insights regarding the architecture and implementation of the platform. This paper proposes a general-purpose microservice-based integration platform, which aims to address limitations of monolithic solutions and of the aforementioned existing proposals. Our work comprises the definition of the platform and its main functionality, a description of its microservice-based architecture, and implementation alternatives as well as prototypes for some of its main components.

Blockchain is a decentralized transaction and data management technology firstly developed for the Bitcoin cryptocurrency. In recent years, the interest in this technology has increased and its use has extended to other scenarios to address, for example, traceability and transparency issues in different application domains (e.g. health, government, art). On the other hand, there is a growing offer of platforms that support this technology with different characteristics (e.g. smart contracts, permissioned). Therefore, the task of identifying which platform is the most suitable for a given scenario is not usually easy. This paper proposes a requirement-driven process for the identification and selection of Blockchain platforms. The process takes as input the business requirements of a particular scenario in order to determine, firstly, the set of characteristics required by the scenario and, secondly, the most suitable Blockchain platforms based on a taxonomy also proposed in this work. The process was assessed through existing projects in the industry that use Blockchain platforms, which allowed validating the adequacy of the proposal.

The integration of software systems running in different healthcare organizations is increasingly required in order exchange data and carrying out healthcare processes in coordinated ways. This integration is usually supported by integration platforms which are based on advanced middleware technologies, like the Enterprise Service Bus (ESB). In addition, data quality in the healthcare area is critical to take timely and accurate decisions for the health and well-being of patients. This paper proposes a data quality aware ESB (DQ-ESB) for e-Health integration platforms which allows assessing and enforcing data quality within inter-organizational data exchanges. DQ-ESB handles an extensible data quality model which includes quality characteristics identified within the Uruguayan e-Health context. DQ-ESB provides data quality solutions based on native ESB mechanisms (e.g. data transformation) and it was implemented leveraging the Switchyard ESB product.

Quality of Service (QoS), applied in particular to Web Services, is an area of increasing interest. One approach to deal with QoS issues is the identification of quality characteristics, usually documented in quality models. Geospatial Web Services are standardized service interfaces which facilitate the processing and exchange of distributed geographic information. These services represent the technological backbone of Spatial Data Infrastructures (SDI), which are data-exchange frameworks geared towards promoting the availability and exploitation of geographic information. This paper proposes a quality model for the evaluation of Geospatial Web Services within IDEuy: the SDI of Uruguay. The development of this model was based on requirements pertaining to the Uruguayan context, leading international SDI initiatives and related work. The application of the model to evaluate services within IDEuy is also presented.

In a context of e-government, there are usually regulatory compliance requirements that the supporting systems should enforce. To this end, an appropriate processing of data coming from different sources is required, which presents an important challenge given the large volume of data that e-government systems handle. This volume of data is also increased with data coming from autonomous sensors (e.g. reporting carbon emission in protected areas) and from citizens providing information (e.g. illegal dumping) in a voluntary way. Complex Event Processing (CEP) technologies allow processing large amount of event data and detecting patterns from them. However, they do not provide support for geographic information which is essential for monitoring and controlling regulations which apply to specific geographical areas. This paper proposes a geospatial extension for CEP that allows monitoring environmental factors considering the geographic location of the processed data.

Public agencies are increasingly required to collaborate with each other in order to provide high-quality e-government services. This collaboration is usually based on the service-oriented approach and supported by interoperability platforms. Such platforms are specialized middleware-based infrastructures enabling the provision, discovery and invocation of interoperable software services. In turn, given that personal data handled by governments are often very sensitive, most governments have developed some sort of legislation focusing on data protection. This paper proposes solutions for monitoring and enforcing data protection laws within an E-government Interoperability Platform. In particular, the proposal addresses the requirements posed by the Uruguayan Data Protection Law and the Uruguayan E-government Platform, although it can also be applied in similar scenarios. The solutions are based on well-known integration mechanisms (e.g. Enterprise Service Bus) as well as recognized security standards (e.g. eXtensible Access Control Markup Language) and were completely prototyped leveraging the SwitchYard ESB product.

Organizations are progressively more required to collaborate with each other in order to achieve their business goals. This had led to the need of integrating the software systems of different, autonomous and geographically distributed organizations. Such integration is increasingly supported by integration platforms which are specialized middleware-based infrastructures that provide an intermediate processing layer, with integration capabilities, between organizations. This paper proposes a reference architecture for integration platforms supporting cross-organizational collaboration. The architecture is presented through four views where the main concepts, use cases and capabilities of these platforms are described.

The Uruguayan e-government agency has made available an Interoperability Platform (InP) with the purpose of facilitating the implementation of e-government services. By leveraging the Web Services technology, public agencies have implemented various atomic services which are usually hosted at the agencies but have to be accessed through proxy services in the InP. Given that the implementation of e-government processes involves invoking multiple services, the mechanisms to implement service orchestrations are increasingly required. Although there are well-known solutions for orchestrating Web Services, their application within the InP presents challenges, in particular, regarding the integration with its Security System. This paper proposes alternatives for implementing orchestrations of secure Web Services within the InP. The proposal consists of a base architecture that can be configured to implement different solution alternatives, enabling its application in other similar scenarios. The proposal was completely prototyped which allowed evaluating some operational aspects of the solution.

Business Process Management (BPM) promotes in organizations a horizontal vision based on the processes they perform to reach their objectives, and on the systems that support them. These systems are "aware" of the business processes they integrate, which guide the system execution (Process Aware Information Systems, PAIS). Automating pieces of these processes by means of services orchestration (mainly web services) allows to integrate to process execution the invocation of legacy systems, systems from other organizations (clients, providers, partners, etc.) and newly developed systems. In this article we present a proposal for the automatic generation of this kind of systems to support business processes with services. The proposal is based on models and transformations between them, from the specification of the business process model in BPMN2, through the services model in SoaML, to the code generated for invoking services from process execution. In particular, the paper provides details on the generation of code in Java EE and Web Services.