# A Study on Improving M2M Network Security through Abnormal Traffic Control
## 5 Conclusions  
In this paper, we proposed a security filter that improves the security and response speed of M2M intelligent network devices through abnormal traffic control in the M2M intelligent network environment. We confirmed the possibility of securing the availability and security of the network used by M2M intelligent network devices by simulating the network packet simulator Ostinato in M2M the intelligent network environment. Security in the M2M intelligent network environment is based on the study of the security enhancement of the device itself. However, due to environmental factors (such as low-capacity hardware) and the installation of security programs (such as antivirus, or OS patches, which can cause problems characteristic of M2M intelligent network devices), it is difficult to strengthen the network security. The security filter proposed in this study can improve the security of the device and the network efficiency by controlling the abnormal traffic generated in the M2M intelligent network environment. We confirmed that it is possible to prevent the damage of third-party DDoS attack damage due to an M2M intelligent network device.  
Experimental results show that the delay of less than 10% depends on the characteristics of the device when the security filter is applied, and that the response speed of the device improves by more than 50% when abnormal traffic occurs. The latency that occurs when applying the security filter is a value that the general user does not feel, but it is necessary to compensate for the increase in the delay time through the tuning of the system and the operating system in which the security filter is installed. M2M intelligent network environments may find it difficult to construct a security filter on the same server as the experimental environment of this work. The application of the security filter in this work with a small Linux device (such as Raspberry), can be applied to various locations and environments. Among the three security factors, 'confidentiality, integrity, and availability', the 'availability' can be increased when we utilize the proposed security filters.  
In addition to M2M intelligent network devices used for the study, it is necessary to verify the packet specificity of more devices and to have more accurate policy tuning methods in the future.  
Conceptualization, S.C.; methodology, S.C. and B.S.; software, S.C.; validation, S.C. and B.S.; formal analysis, S.C. and B.S.; investigation, S.C.; resources, S.C.; data curation, S.C.; writing--original draft preparation, S.C.; writing--review and editing, B.S.; visualization, S.C.; supervision, B.S.; project administration, S.C. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
This research was supported by the Mid-Career Researcher program through the National Research Foundation of Korea (NRF) funded by the MSIT (Ministry of Science and ICT) under Grant 2020R1A2C2014336.  
The authors declare no conflict of interest.  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **Experiment (a) Air Cleaner** & **Experiment (b) 220v Plugin** \\ \hline Security filter not used & 4000–4500 millisecond & 6000 millisecond \\ Applying Security Filters & 1000–1500 millisecond & 3000 millisecond \\ \hline \hline \end{tabular}
\end{table}
Table 4: Device response time when security filter is applied after abnormal packet input.  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **Experiment (a) Air Cleaner** & **Experiment (b) 220v Plugin** \\ \hline Security filter not used & 0.800 millisecond & 2000 millisecond \\ Applying Security Filters & 0.900 millisecond & 2200 millisecond \\ \hline \hline \end{tabular}
\end{table}
Table 3: Device response time when security filter is applied in normal state.