Engineering Secure Adaptable Web Services Compositions

Service-oriented architecture defines a paradigm for building applications by assembling autonomous components such as web services to create web service compositions. Web services are executed in complex contexts where unforeseen events may compromise the security of the web services composition. If such compositions perform critical functions, prompt action may be required as new security threats may arise at runtime. Manual interventions may not be ideal or feasible. To automatically decide on valid security changes to make at runtime, the composition needs to make use of current security context information. Such security changes are referred to as dynamic adaptation. This research proposes a framework to develop web services compositions that can dynamically adapt to maintain the same level of security when unforeseen security events occur at runtime. The framework is supported by mechanisms that map revised security requirements arising at runtime to a new security configuration plan that is used to adapt the web services composition

Koostööäriprotsesside läbiviimine plokiahelal: süsteem

Tänapäeval peavad organisatsioonid tegema omavahel koostööd, et kasutada ära üksteise täiendavaid võimekusi ning seeläbi pakkuda oma klientidele parimaid tooteid ja teenuseid. Selleks peavad organisatsioonid juhtima äriprotsesse, mis ületavad nende organisatsioonilisi piire. Selliseid protsesse nimetatakse koostööäriprotsessideks. Üks peamisi takistusi koostööäriprotsesside elluviimisel on osapooltevahelise usalduse puudumine. Plokiahel loob detsentraliseeritud pearaamatu, mida ei saa võltsida ning mis toetab nutikate lepingute täitmist. Nii on võimalik teha koostööd ebausaldusväärsete osapoolte vahel ilma kesksele asutusele tuginemata. Paraku on aga äriprotsesside läbiviimine selliseid madala taseme plokiahela elemente kasutades tülikas, veaohtlik ja erioskusi nõudev. Seevastu juba väljakujunenud äriprotsesside juhtimissüsteemid (Business Process Management System – BPMS) pakuvad käepäraseid abstraheeringuid protsessidele orienteeritud rakenduste kiireks arendamiseks. Käesolev doktoritöö käsitleb koostööäriprotsesside automatiseeritud läbiviimist plokiahela tehnoloogiat kasutades, kombineerides traditsioonliste BPMS- ide arendusvõimalused plokiahelast tuleneva suurendatud usaldusega. Samuti käsitleb antud doktoritöö küsimust, kuidas pakkuda tuge olukordades, milles uued osapooled võivad jooksvalt protsessiga liituda, mistõttu on vajalik tagada paindlikkus äriprotsessi marsruutimisloogika muutmise osas. Doktoritöö uurib tarkvaraarhitektuurilisi lähenemisviise ja modelleerimise kontseptsioone, pakkudes välja disainipõhimõtteid ja nõudeid, mida rakendatakse uudsel plokiahela baasil loodud äriprotsessi juhtimissüsteemil CATERPILLAR. CATERPILLAR-i süsteem toetab kahte lähenemist plokiahelal põhinevate protsesside rakendamiseks, läbiviimiseks ja seireks: kompileeritud ja tõlgendatatud. Samuti toetab see kahte kontrollitud paindlikkuse mehhanismi, mille abil saavad protsessis osalejad ühiselt otsustada, kuidas protsessi selle täitmise ajal uuendada ning anda ja eemaldada osaliste juurdepääsuõigusi.Nowadays, organizations are pressed to collaborate in order to take advantage of their complementary capabilities and to provide best-of-breed products and services to their customers. To do so, organizations need to manage business processes that span beyond their organizational boundaries. Such processes are called collaborative business processes. One of the main roadblocks to implementing collaborative business processes is the lack of trust between the participants. Blockchain provides a decentralized ledger that cannot be tamper with, that supports the execution of programs called smart contracts. These features allow executing collaborative processes between untrusted parties and without relying on a central authority. However, implementing collaborative business processes in blockchain can be cumbersome, error-prone and requires specialized skills. In contrast, established Business Process Management Systems (BPMSs) provide convenient abstractions for rapid development of process-oriented applications. This thesis addresses the problem of automating the execution of collaborative business processes on top of blockchain technology in a way that takes advantage of the trust-enhancing capabilities of this technology while offering the development convenience of traditional BPMSs. The thesis also addresses the question of how to support scenarios in which new parties may be onboarded at runtime, and in which parties need to have the flexibility to change the default routing logic of the business process. We explore architectural approaches and modelling concepts, formulating design principles and requirements that are implemented in a novel blockchain-based BPMS named CATERPILLAR. The CATERPILLAR system supports two methods to implement, execute and monitor blockchain-based processes: compiled and interpreted. It also supports two mechanisms for controlled flexibility; i.e., participants can collectively decide on updating the process during its execution as well as granting and revoking access to parties.https://www.ester.ee/record=b536494

A generic provenance framework to document public policy making processes

Public policies impact the day to day activities of individuals. Effective public policy outcomes result in general acceptance among the community. The transparency in policy making process and participation during policy creation holds significant positions for developing trust among the community. Established domains such as e-health employs provenance for creating transparency and trust among the researchers. Public policy making can also use provenance to develop trust and transparency in their processes. At present, however, public policy makers employ various means to manage public policy making. Having no unified platform for the policy making process presents challenges in respect of searching and locating the evidence that was used during policy creation and for ensuring trust and transparency among actors. The absence of such a support also presents challenges for participation in public policy making. To address the given challenges, this research presents the provenance framework that manages the public policy making provenance data and enable participation of diverse actors.Due to dynamicity attached to public policy making, a provenance framework needs to be adaptable. Therefore, a model-driven approach has been used to frame the public policy making provenance framework. In addition to a model-driven approach, a mechanism is required that can enable the capture of public policy processes. However, the knowledge-intensive dynamics of public policy making presents challenges for using process-based solutions. Therefore, this research work describes a process-agnostic approach inspired from a network-based packet switching approach for tracking policy making processes. Managing public policy provenance data is not the only facet that develops trust. What is required is the facilitation of citizens and non-government bodies in the policy creation process. Therefore, a provenance framework has been designed by considering the principles of smart governance which results in a smart cities solution. In order to evaluate the framework, a proof-of-concept has been designed and implemented. An evaluation has been carried out to determine the suitability of a model-driven and a process-agnostic approach for policy making provenance framework in smart cities. For the evaluation purposes, three public policy making case studies Shops Opening Hours’ Resolution, Air Quality Monitoring, and Neighbourhood Planning were employed. The three case studies were used to derive various experiments to test the provenance framework. The experiments captured the dynamic and knowledge-intensive aspects of the provenance framework. The results collected from the execution of the experiments demonstrated the aptness of a process-agnostic approach and model-driven approach for the policy making provenance framework. Lastly, an end user evaluation was carried out to assess the effectiveness of the provenance framework. The positive responses of end users showed the usefulness of the provenance framework