  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.
