Abstract
Modern industrial systems are enriched by cyber–physical devices and interconnections with business processes that enable flexible production, remote monitoring, control and maintenance. These systems are typically subject to multiple authorities which must cooperate with each other, as in the case of segmented industrial environments and supply chains. In similar contexts, voluntary or unintentional damages may be caused by cyber attacks or by misbehaving authorized parties. We propose an original architecture that regulates accesses to industrial systems’ resources through authorization delegation procedures. It guarantees several benefits that include the possibility of auditing authorizations released by delegated third parties, of detecting misconducts and possible attacks, and of assuring attribution of misconducts. The proposed solution is compatible with constraints characterizing industrial environments and with security and performance requirements of industrial architectures. The performance and latencies of the auditing mechanisms are evaluated through a prototype.
1. Introduction
Modern enterprises are deploying a large amount of IoT devices and interconnections among production plants and business infrastructures, building so-called Industrial Internet-of-Things (IIoT) [1]. These components can provide enterprises with advantages in terms of flexibility, productivity, management through remote monitoring and control [2], fast detection and even prediction of component failures [3, 4], and continuous data exchange among supply chain partners [1,5]. However, they open new attack surfaces that increase the cyber vulnerability of industrial infrastructures. Trustworthy industrial systems must ensure safety of people and infrastructure security, operation continuity and reliability. Any violation of these requirements must be prevented or at least audited with the twofold goal of identifying the causes and attributing the fault to the entities and operations that have caused the problem [6].
6. Conclusions
We propose a system that allows to audit authorization procedures operated in industrial IoT environments, characterized by highly secure air-gapped systems and devices with low resources placed in constrained environments. The proposed design is compliant with standard authorization and network communication protocols and can leverage existing software services and libraries for a reliable deployment. Its security is based on established cryptographic protocols, such as standard digital signature schemes and hash functions, and allows each party involved in the system to prove misbehaviors publicly, incentivizing each industrial party involved in a collaboration to adopt the best security practices to avoid misbehaviors due to internal or external adversaries. The proposed experimental evaluation operated by using a prototype implementation based on the established Google Trillian project, shows the feasibility of the system even in presence of intensive operation workloads.
