  Industry 4.0 uses a subset of the IoT, named Industrial IoT (IIoT), to
achieve connectivity, interoperability, and decentralization. The deployment of
industrial networks rarely considers security by design, but this becomes
imperative in smart manufacturing as connectivity increases. The combination of
OT and IT infrastructures in Industry 4.0 adds new security threats beyond
those of traditional industrial networks. Defence-in-Depth (DiD) strategies
tackle the complexity of this problem by providing multiple defense layers,
each of these focusing on a particular set of threats. Additionally, the strict
requirements of IIoT networks demand lightweight encryption algorithms.
Nevertheless, these ciphers must provide E2E (End-to-End) security, as data
passes through intermediate entities or middleboxes before reaching their
destination. If compromised, middleboxes could expose vulnerable information to
potential attackers if it is not encrypted throughout this path. This paper
presents an analysis of the most relevant security strategies in Industry 4.0,
focusing primarily on DiD. With these in mind, it proposes a combination of
DiD, an encryption algorithm called Attribute-Based-Encryption (ABE), and
object security (i.e., OSCORE) to get an E2E security approach. This analysis
is a critical first step to developing more complex and lightweight security
frameworks suitable for Industry 4.0.
