This paper introduces an evolving cybersecurity knowledge graph that integrates and links critical information on real-world vulnerabilities, weaknesses and attack patterns from various publicly available sources. Cybersecurity constitutes a particularly interesting domain for the development of a domain-specific public knowledge graph, particularly due to its highly dynamic landscape characterized by time-critical, dispersed, and heterogeneous information. To build and continually maintain a knowledge graph, we provide and describe an integrated set of resources, including vocabularies derived from well-established standards in the cybersecurity domain, an ETL workflow that updates the knowledge graph as new information becomes available, and a set of services that provide integrated access through multiple interfaces. The resulting semantic resource offers comprehensive and integrated up-to-date instance information to security researchers and professionals alike. Furthermore, it can be easily linked to locally available information, as we demonstrate by means of two use cases in the context of vulnerability assessment and intrusion detection.

For decades, researchers and practitioners develop various approaches such as Web Service technologies (e.g., UDDI, WSDL, SOAP) to address application integration problems. In particular, Web Service composition methods can solve complex service integrations. However, in highly dynamic environments, these manual service compositions still requires a lot of effort. To address this challenge, researchers have recently introduced semantic web service composition methods. The growing interest in this topic of semantic web service composition has led to an increasing number of approaches, which has not been systematically surveyed so far. Researchers have reported several surveys in the related areas such as web service composition or semantic web service search. However, to the best of our knowledge, none of them provides a survey about these semantic web service compositions in particular. Hence, this review aims to address this issue by identifying existing efforts on semantic web service compositions. The survey focuses on two aspects (i) semantic web service description, as it is an essential aspect for semantic service composition, (ii) semantic web service composition, to identify methods and their implementations on the real world problem.

The integration of heterogeneous and weakly linked log data poses a major challenge in many log-analytic applications. Knowledge graphs (KGs) can facilitate such integration by providing a versatile representation that can interlink objects of interest and enrich log events with background knowledge. Furthermore, graph-pattern based query languages, such as SPARQL, can support rich log analyses by leveraging semantic relationships between objects in heterogeneous log streams. Constructing, materializing, and maintaining centralized log knowledge graphs, however, poses significant challenges. To tackle this issue, we propose VloGraph—a distributed and virtualized alternative to centralized log knowledge graph construction. The proposed approach does not involve any a priori parsing, aggregation, and processing of log data, but dynamically constructs a virtual log KG from heterogeneous raw log sources across multiple hosts. To explore the feasibility of this approach, we developed a prototype and demonstrate its applicability to three scenarios. Furthermore, we evaluate the approach in various experimental settings with multiple heterogeneous log sources and machines; the encouraging results from this evaluation suggest that the approach can enable efficient graph-based ad-hoc log analyses in federated settings.