  The technological evolution brought by the Internet of things (IoT) comes
with new forms of cyber-attacks exploiting the complexity and heterogeneity of
IoT networks, as well as, the existence of many vulnerabilities in IoT devices.
The detection of compromised devices, as well as the collection and
preservation of evidence regarding alleged malicious behavior in IoT networks
emerge as a areas of high priority. This paper presents a blockchain-based
solution, which is designed for the smart home domain, dealing with the
collection and preservation of digital forensic evidence. The system utilizes a
private forensic evidence database, where the captured evidence is stored,
along with a permissioned blockchain that allows providing security services
like integrity, authentication, and non-repudiation, so that the evidence can
be used in a court of law. The blockchain stores evidences' metadata, which are
critical for providing the aforementioned services, and interacts via smart
contracts with the different entities involved in an investigation process,
including Internet service providers, law enforcement agencies and prosecutors.
A high-level architecture of the blockchain-based solution is presented that
allows tackling the unique challenges posed by the need for digitally handling
forensic evidence collected from IoT networks.
