The dependency of our society on networked computers has become frightening: In the economy, all-digital networks have turned from facilitators to drivers; as cyber-physical systems are coming of age, computer networks are now becoming the central nervous systems of our physical world-even of highly critical infrastructures such as the power grid. At the same time, the 24/7 availability and correct functioning of networked computers has become much more threatened: The number of sophisticated and highly tailored attacks on IT systems has significantly increased. Intrusion Detection Systems (IDSs) are a key component of the corresponding defense measures; they have been extensively studied and utilized in the past. Since conventional IDSs are not scalable to big company networks and beyond, nor to massively parallel attacks, Collaborative IDSs (CIDSs) have emerged. They consist of several monitoring components that collect and exchange data. Depending on the specific CIDS architecture, central or distributed analysis components mine the gathered data to identify attacks. Resulting alerts are correlated among multiple monitors in order to create a holistic view of the network monitored. This article first determines relevant requirements for CIDSs; it then differentiates distinct building blocks as a basis for introducing a CIDS design space and for discussing it with respect to requirements. Based on this design space, attacks that evade CIDSs and attacks on the availability of the CIDSs themselves are discussed. The entire framework of requirements, building blocks, and attacks as introduced is then used for a comprehensive analysis of the state of the art in collaborative intrusion detection, including a detailed survey and comparison of specific CIDS approaches.

The Internet of Things (IoT) brings together a multitude of technologies, with a vision of creating an interconnected world. This will benefit both corporations as well as the endusers. However, a plethora of security and privacy challenges need to be addressed for the IoT to be fully realized. In this paper, we identify and discuss the properties that constitute the uniqueness of the IoT in terms of the upcoming security and privacy challenges. Furthermore, we construct requirements induced by the aforementioned properties. We survey the four most dominant IoT architectures and analyze their security and privacy components with respect to the requirements. Our analysis shows a mediocre coverage of security and privacy requirements. Finally, through our survey we identify a number of research gaps that constitute the steps ahead for future research.

In an attempt to cope with the increased number of cyberattacks, research in Intrusion Detection Systems (IDSs) is moving towards more collaborative mechanisms. Collaborative IDSs (CIDSs) are such an approach; they combine the knowledge of a plethora of monitors to generate a holistic picture of the monitored network. Despite the research done in this field, CIDSs still face a number of fundamental challenges, especially regarding maintaining trust among the collaborating parties. Recent advances in distributed ledger technologies, e.g. various implementations of blockchain protocols, are a good fit to the problem of enhancing trust in collaborative environments. This paper touches the intersection of CIDSs and blockchains. Particularly, it introduces the idea of utilizing blockchain technologies as a mechanism for improving CIDSs. We argue that certain properties of blockchains can be of significant benefit for CIDSs; namely for the improvement of trust between monitors, and for providing accountability and consensus. For this, we study the related work and highlight the research gaps and challenges towards such a task. Finally, we propose a generic architecture for the incorporation of blockchains into the field of CIDSs and an analysis of the design decisions that need to be made to implement such an architecture.

The number of smart things is growing exponentially. By 2020, tens of billions of things will be deployed worldwide, collecting a wealth of diverse data. Traditional computing models collect in-field data and then transmit it to a central data center where analytics are applied to it, but this is no longer a sustainable model. New approaches and new technologies are required to transform enormous amounts of collected data into meaningful information. Technology also will enable the interconnection around things in the IoT ecosystem but further research is required in the development, convergence and interoperability of the different IoT elements. In this paper, we provide a picture of the main technological components needed to enable the interconnection among things in order to realize IoT concepts and applications.978-1-4799-5344-8/15/$31.00 ©2015 IEEE

Cyber-attacks are steadily increasing in both their size and sophistication. To cope with this, Intrusion Detection Systems (IDSs) are considered mandatory for the protection of critical infrastructure. Furthermore, research is currently focusing on collaborative architectures for IDSs, creating a Collaborative IDS (CIDS). In such a system a number of IDS monitors work together towards creating a holistic picture of the monitored network. Nevertheless, a class of attacks exists, called probe-response, which can assist adversaries to detect the network position of CIDS monitors. This can significantly affect the advantages of a CIDS. In this paper, we introduce PREPARE, a framework for deploying probe-response attacks and also for studying methods for their mitigation. Moreover, we present significant improvements on both the effectiveness of probe-response attacks as well as on mitigation techniques for detecting them. We evaluate our approach via an extensive simulation and a real-world attack deployment that targets two CIDSs. Our results show that our framework can be practically utilized, that our proposals significantly improve probe-response attacks and, lastly, that the introduced detection and mitigation techniques are effective.