A relatively new trend in Critical Infrastructures (e.g., power plants, nuclear plants, energy grids, etc.) is the massive migration from the classic model of isolated systems, to a system-of-systems model, where these infrastructures are intensifying their interconnections through Information and Communications Technology (ICT) means. The ICT core of these industrial installations is known as Supervisory Control And Data Acquisition Systems (SCADA). Traditional ICT security countermeasures (e.g., classic firewalls, anti-viruses and IDSs) fail in providing a complete protection to these systems since their needs are different from those of traditional ICT. This paper presents an innovative approach to Intrusion Detection in SCADA systems based on the concept of Critical State Analysis and State Proximity. The theoretical framework is supported by tests conducted with an Intrusion Detection System prototype implementing the proposed detection approach.

In this article, we introduce a comprehensive framework supporting a privacy-aware access control mechanism, that is, a mechanism tailored to enforce access control to data containing personally identifiable information and, as such, privacy sensitive. The key component of the framework is a family of models (P-RBAC) that extend the well-known RBAC model in order to provide full support for expressing highly complex privacy-related policies, taking into account features like purposes and obligations. We formally define the notion of privacy-aware permissions and the notion of conflicting permission assignments in P-RBAC, together with efficient conflict-checking algorithms. The framework also includes a flexible authoring tool, based on the use of the SPARCLE system, supporting the high-level specification of P-RBAC permissions. SPARCLE supports the use of natural language for authoring policies and is able to automatically generate P-RBAC permissions from these natural language specifications. In the article, we also report performance evaluation results and contrast our approach with other relevant access control and privacy policy frameworks such as P3P, EPAL, and XACML.

The security of Industrial Critical Infrastructures is become a prominent problem with the advent of modern ICT technologies used to improve the performances and the features of the SCADA systems. In this paper we present an innovative approach to the design of Intrusion Detection Systems. The aim is to be able to detect complex attacks to SCADA systems, by monitoring its state evolution. By complex attack, we mean attacks composed of a set of commands that, while licit when considered in isolation on a single-packet basis, can disrupt the correct behavior of the system when executed in particular operating states. The proposed IDS detects these complex attacks thanks to an internal representation of the controlled SCADA system. We also present the corresponding rule language powerful enough to express the system's critical states. Furthermore, we present a prototype of the proposed IDS, able to monitor systems using the ModBus and DNP3 communication protocols.

Privacy has been acknowledged to be a critical requirement for many business (and non-business) environments. Therefore, the definition of an expressive and easy-to-use privacy related access control model, based on which privacy policies can be specified, is crucial. In this work we introduce a family of models (P-RBAC) that extend the well known RBAC model in order to provide full support for expressing highly complex privacy-related policies, taking into account features like purposes and obligations. We also compare our work with access control and privacy policy frameworks such as P3P, EPAL, and XACML