  This paper considers the use of novel technologies for mitigating attacks
that aim at compromising intrusion detection systems (IDSs). Solutions based on
collaborative intrusion detection networks (CIDNs) could increase the
resilience against such attacks as they allow IDS nodes to gain knowledge from
each other by sharing information. However, despite the vast research in this
area, trust management issues still pose significant challenges and recent
works investigate whether these could be addressed by relying on blockchain and
related distributed ledger technologies. Towards that direction, the paper
proposes the use of a trust-based blockchain in CIDNs, referred to as
trust-chain, to protect the integrity of the information shared among the CIDN
peers, enhance their accountability, and secure their collaboration by
thwarting insider attacks. A consensus protocol is proposed for CIDNs, which is
a combination of a proof-of-stake and proof-of-work protocols, to enable
collaborative IDS nodes to maintain a reliable and tampered-resistant
trust-chain.
