Jacek Kopecký’s research while affiliated with University of Portsmouth and other places

In this paper we outline the challenges of Web API management in Internet of Things (IoT) projects. Web API management is a key aspect of service-oriented systems that includes the following elements: metadata publishing, access control and key management, monitoring and monetization of interactions, as well as usage control and throttling. We look at how Web API management principles, including some of the above elements, translate into a world of connected devices (IoT). In particular, we present and evaluate a prototype that addresses the issue of managing authentication with millions of insecure low-power devices communicating with non-HTTP protocols. With this first step, we are only beginning to investigate IoT API management, therefore we also discuss necessary future work.

Service-oriented computing has brought special attention to service description, especially in connection with semantic technologies. The expected proliferation of publicly accessible services can benefit greatly from tool support and automation, both of which are the focus of Semantic Web Service (SWS) frameworks that especially address service discovery, composition and execution. As the first SWS standard, in 2007 the World Wide Web Consortium produced a lightweight bottom-up specification called SAWSDL for adding semantic annotations to WSDL service descriptions. Building on SAWSDL, this article presents WSMO-Lite, a lightweight ontology of Web service semantics that distinguishes four semantic aspects of services: function, behavior, information model, and nonfunctional properties, which together form a basis for semantic automation. With the WSMO-Lite ontology, SAWSDL descriptions enable semantic automation beyond simple input/output matchmaking that is supported by SAWSDL itself. Further, to broaden the reach of WSMO-Lite and SAWSDL tools to the increasingly common RESTful services, the article adds hRESTS and MicroWSMO, two HTML microformats that mirror WSDL and SAWSDL in the documentation of RESTful services, enabling combining RESTful services with WSDL-based ones in a single semantic framework. To demonstrate the feasibility and versatility of this approach, the article presents common algorithms for Web service discovery and composition adapted to WSMO-Lite.

Abstract—We examine the use of Federated Identity and Access Management (FIAM) approaches for the Internet of Things (IoT). We look at specific challenges that devices, sensors and actuators have, and look for approaches to address them. OAuth is a widely deployed protocol – built on top of HTTP – for applying FIAM to Web systems. We explore the use of OAuth for IoT systems that instead use the lightweight MQTT 3.1 protocol. In order to evaluate this area, we built a prototype that uses OAuth 2.0 to enable access control to information distributed via MQTT. We evaluate the results of this prototyping activity, and assess the strengths and weaknesses of this approach, and the benefits of using the FIAM approaches with IoT and Machine to Machine (M2M) scenarios. Finally we outline areas for further research.

Despite the potential of service-orientation and the efforts devoted so far, we are still to witness a significant uptake of service technologies outside of enterprise environments. A core reason for this limited uptake is the lack of appropriate publishing platforms able to deal with the existing heterogeneity in the service technologies landscape and able to provide expressive yet simple and ecient discovery mechanisms. In this paper we describe iServe, a novel and open platform for publishing services which aims to better support their discovery and use. It exposes service descriptions as linked data expressed in terms of a simple vocabulary for describing services of different kinds with annotations in diverse formalisms. In addition to describing iServe, this paper also highlights the set of principles behind iServe, which we believe are essential for other generic repositories of semantic information notably ontology repositories.

Distributed information systems predominantly have client-server architectures, as does the Web itself. In this article, we review the evolution of the interface of client-server distributed systems, from Messaging and RPC systems that predate the Web, to RESTful Web APIs. We highlight the often overlooked importance of the client-server interface in Web applications, and we reference historic and current systems to discuss the roles of “Web Service” technologies and Service-Oriented Architectures. Considering the future, we point out four directions in which we can see Web APIs moving, including the incorporation of hypermedia and semantics.

The Linked Data effort has been focusing on how to publish open data sets on the Web, and it has had great results. However, mechanisms for updating linked data sources have been neglected in research. We propose a structure for Linked Data resources in named graphs, connected through hyperlinks and self-described with light metadata, that is a natural match for using standard HTTP methods to implement application-specific (high-level) public update APIs.

The past few years have been marked by the rapid increase in popularity and use of Web APIs as indicated by the growing number of available APIs and the multitude of applications built on top of them. The development and evolution of applications based on Web APIs is, however, hampered by the lack of automation achievable with current technologies. In this paper, we focus in particular on invocation, which as of now requires manual implementation of custom-tailored clients for each individual API. We present an approach for employing lightweight semantics for supporting the automated invocation of Web APIs. We investigate current Web API description forms and conduct an analysis of the requirements for a description model capable of supporting unified API invocation. In the light of these results, we propose a shared API description model that overcomes the current heterogeneity of the documentation and provides common grounds for enhancing APIs with semantic annotations that facilitate a general automated invocation solution. We evaluate the applicability of our approach by determining the coverage provided by our description model and via a prototypical implementation of an invocation engine.