# Smart Grid Architecture for Rural Distribution Networks: Application to a Spanish Pilot Network
## 4 New Electrical Configurations and Operation Modes
### Analysis in Vulnerabilities on Communications and Related Management Plan  
The PN operation depends highly on a wide sensory and monitoring system, and a collection of automated switch-disconnectors and electrical power switches. All of these are remotely managed through the telecommunications system. Initially, the telecommunication systems of electric power systems were limited, small and carefully isolated from the other telecommunication systems in order to guarantee their own security. However, the continued growth of the network, the increment of data volume, and the obsolescence of their infrastructure force the use of new wireless or wired channels that pass the data through the public telecommunication network. In addition, the lack of cybersecurity, the lack of safety, and the unencrypted protocols are provoking that the cyberattacks are becoming increasingly common, representing a vulnerability. In addition, in terms of cybersecurity, like the telecommunications systems, the SCADA system is also critical and crucial. This is because it provides three vital functions, which are data acquisition, supervisory control and alarm display, centralising the communications and network management. The SCADA polls periodically the RTUs to gather the real-time measurement data from all the substations and sends out control signals to the specific remote devices. Therefore, a proper cybersecurity protection system should be provided, in order to avoid a route for hackers from that creates a disruption, takes control, or causes damage. The SRG potential vulnerabilities are inherited from the traditional telecommunications and management systems. These are outdated private telecommunication networks; the embedded and default passwords that were not changed; and the use of unsafely protocols like hypertext transfer, Telnet and trivial file transfer protocols. Different ways have been selected to reinforce the cybersecurity in the SRG project. The first way is creating a secure channel over an unsecured network (e.g., the public telecommunication network). For instance, the wireless networks are experiencing a great reception in control environments due to the important advantages they provide, and they can pose a significant risk due to the continuous technological change to which they are subjected. To create a secure channel over these unsecure networks, the Secure Shell (SSH) protocol is deployed. The SSH is a cryptographic network protocol for operating services securely over an unsecured telecommunication network. The SSH protocol supports secure remote logins, commands, file transfers, access control, etc. [58]. Furthermore, the Asymmetric Encryption Standard algorithm is the selected technique for encrypting the data exchanged. The second way is establishing VPNs. A VPN creates a safe and encrypted connection over less secure networks, which is employed to securely connect geographically separated facilities forming one unified telecommunication network. The access to such VPNs is restricted. To do so, two techniques are adopted: the first one is using an adequate and unique password, and the second one is controlling the physical port access. In terms of passwords and keys, they periodically expire and they are subjected to dedicated policies (e.g., default passwords are forbidden, a minimum level of complexity is required). In addition, the internet access for these VPNs is absolutely restricted. The physical port access protection measures have been implemented mainly installing the technology inside cabinets protected under key and restricting the use of Universal Series Bus technology. Furthermore, the network architecture is minimised, so the number of connections with the system is the minimum required.The third way of reinforcing the cybersecurity is identifying and removing all unnecessary services in order to get an extra level of security to be simpler, reliable and secure. Disused ports and services are disabled in order to prevent unauthorized use.