Guest Editorial

This issue features the first part of the special issue on Security and Privacy in Complex Systems. In response to the call for papers we received 123 submissions, an overwhelming response attesting to the significance of the topic and its interest in the research community. These papers were evaluated on the basis of their significance, novelty, and technical quality. The reviewing process was carried out by an editorial board composed of experts in the field, to whom we are grateful for their dedicated and committed work in the process. Of the papers submitted, 28 were accepted for publication in the journal, giving an acceptance rate lower than 23%. Due to page constraints, these 28 papers have been divided in two issues; each issue includes 14 papers that address different aspects related to security and privacy in complex systems.