## 4 Practical Mobility Management in Modern Scenarios
### Dealing with Mobility via VPN Applications  
WireGuard [32; 33; 34; 35] is a free software (registered trademarks of [PERSON]) recently established in the IT market for creating VPNs, allowing efficient management to regulate access to certain network resources and isolating user's data flow from the outside world. It is also defined as the \"the Next Generation Kernel Network Tunnel\" software [36], and it belongs to the Noise Protocol Framework [37]. It is a free tool under the GPLv2 license, written in the \"C\" and \"Go\" languages and works with Windows, macOS, BSD, iOS and Android. It offers optimizations for mobile devices and IoT systems. Given its excellent features, it has been integrated directly into the Linux kernel, making it virtually available on all connected devices around the world, which is also possible because it is relatively light and has very low hardware requirements. WireGuard is based on so-called Cryptokey Routing, where the IP addresses of the tunnel are assigned in a one-to-one mode to the peer's public key for decryption of incoming packets, which are delivered only if they come from the address corresponding to the key. WireGuard does not negotiate the cryptographic bases of the handshake individually, but only a subset of them. If one of the cryptographic bases is no longer secure, a new version of the protocol is published to protect the data flow. One of the strengths of WireGuard is its codebase, consisting of about 4000 lines of code compared to those of OpenVPN or IPsec which are, respectively, 10,000 and 600,000, and is therefore intrinsically more secure because it is easily maintainable  
\begin{table}
\begin{tabular}{c c} \hline \hline
**VLANs** & **VPNs** \\ \hline They can shield the data so that it does not behave as if it is on the same & Create a virtual tunnel for secure data transmission over the Internet. \\ \hline They allow the grouping of devices scattered across multiple physical & Provide encryption and anonymization. \\ locations into a single transmission domain. & They increase the overall efficiency of a network \\ \hline They can be intended as a subcategory of VPNs. & distributed over multiple geographic locations \\ \hline Optimal for splitting a network into logical parts for better & Operates in an unsecured online environment \\ management, but they do not provide any security features. & by definition. \\ \hline Reduce the need for routers and the expense of managing them. & Enable users to reliably send and receive sensitive data \\ by providing an encrypted connection over the Internet. \\ \hline They remove latency in the network and improve its efficiency, facilitate & They allow connection partners to securely facilitate the \\ its management and scalability, and save HW network resources. & transmission of sensitive data. \\ \hline They use the layer-two frame tag for encapsulation and can scale up to & Mitigate access attempts by malicious hackers by \\  
and with a minimal attack surface. The codebase guarantees greater security and higher performance. By providing higher transmission speed and lower latency than historic protocols, if no data is passing through the tunnel, WireGuard is \"at rest\", thus reducing the amount of used energy. It provides very useful features for use in the mobile and IOT world, thanks to roaming support from the Wi-Fi network to the mobile phone network and vice versa. In fact, in [33], the protocol underlying WireGuard is deeply analyzed and tested by the CryptoVerif proof assistant. The authors conducted a large, deep analysis of WireGuard signaling messages (such as the transport data messages), proofing and confirming the goodness of the VPN in terms of secrecy, authentication, session uniqueness, replay attacks, etc. The authors of [34], instead, demonstrated how data security can be guaranteed by WireGuard in a real VPN, involving a laboratory and several African universities. The authors coupled WireGuard and Apache Guacamole, testing the strength of the considered VPN in terms of secrecy robustness.