# A Review of Industry 4.0 Manufacturing Process Security Risks
## 4 Solutions
### Securing the Manufacturing Information Architecture  
#### 4.1.1 Network Security and Information Flow  
The digital manufacturing information architecture presents a large number of attack vectors, each unique in its own sense. Since the interception of manufacturing information occurs via the communications network, there are two possibilities for securing the information flow [8]. The first is to secure the entire network by routing all traffic through a single entity that interconnects all the relevant equipment in the manufacturing architecture, such as the case of a typical IT network architecture, for example with firewalls and intrusion detection software. Although this approach sounds plausible, there are a number of problems with it. The first is the fact that the digital manufacturing architecture consists of a combination of IT and OT devices. As discussed in Section 2.2, OT equipment typically does not have the same computing power as IT equipment. Therefore, any form of network management and security solution typically implemented in an IT environment would not be practical in a network with a combination of IT and OT equipment. Although the computing capability of many embedded platforms utilized in OT equipment has increased significantly since the introduction of the first embedded platform OT equipment, it could still cause a bottleneck that would introduce intermittent delays or disruptions in the manufacturing process. OT equipment, particularly in the IIoT perspective, is generally not designed to have high throughput, since a bandwidth limitation is applicable. Therefore, most OT equipment in use today communicates over simple communication protocols, where relatively little information is transferred between platforms. In many manufacturing processes where process timing is essential, an unexpected delay in the order of milliseconds could have a significant impact on the manufacturing process outcome [9]. It is therefore clear that any security measure that would introduce such a delay is not a viable solution in this context. Because of the constant evolution of malicious tactics used to compromise security networks, regular updates to the security software are required to ensure that a network remains protected against the latest forms of attack. In a typical IT infrastructure, this would involve a download of the latest security updates, and sometimes even a system reboot. Such a system reboot could result in unplanned down-time of machinery, which could hugely influence a manufacturing process. Such security updates would have to be scheduled well in advance to ensure that the impact on the production line is limited. This once again emphasizes the incompatibility of IT security measures used in an OT environment. A viable security solution would thus be one that considers system availability as the highest priority. Another crucial aspect that must be considered when proposing a solution to the security problem in OT networks is that of the current infrastructure used by manufacturers. In contrast to the approach to building an IT network with IT equipment that can easily be replaced or upgraded as requirementschange, manufacturing entities normally procure OT equipment with the focus on longevity and term robustness. Whereas some IT equipment could be replaced or upgraded within a five-year timeframe, OT equipment typically remains in service for much longer time frames, sometimes in the order of decades. The conclusion can then be drawn that much of the OT equipment currently in use by manufacturers could already be decades old. In such cases there is most probably much more advanced and sophisticated equipment available that would be ideal replacements for this old equipment. However, upgrading OT infrastructure with newer equipment is not as easy as installing a new printer and updating some drivers.