Günther Pernul

Benedikt Putz, Fabian Böhm, Günther Pernul

Today, permissioned blockchains are being adopted by large organizations for business critical operations. Consequently, they are subject to attacks by malicious actors. Researchers have discovered and enumerated a number of attacks that could threaten availability, integrity and confidentiality of blockchain data. However, currently it remains difficult to detect these attacks. We argue that security experts need appropriate visualizations to assist them in detecting attacks on blockchain networks. To achieve this, we develop HyperSec, a visual analytics monitoring tool that provides relevant information at a glance to detect ongoing attacks on Hyperledger Fabric. For evaluation, we connect the HyperSec prototype to a Hyperledger Fabric test network. The results show that common attacks on Fabric can be detected by a security expert using HyperSec's visualizations.

Alexandra Cetto, Michael Netter, Günther Pernul et al.

Currently, many users of Social Network Sites are insufficiently aware of who can see their shared personal items. Nonetheless, most approaches focus on enhancing privacy in Social Networks through improved privacy settings, neglecting the fact that privacy awareness is a prerequisite for privacy control. Social Network users first need to know about privacy issues before being able to make adjustments. In this paper, we introduce Friend Inspector, a serious game that allows its users to playfully increase their privacy awareness on Facebook. Since its launch, Friend Inspector has attracted a significant number of visitors, emphasising the need for better tools to understand privacy settings on Social Networks.