# Enhancing Resilience in Digital Twins: ASCON-Based Security Solutions for Industry 4.0
## 3 Proposed Solution
### Ditto Java Base Payload Mapping
For the memory usage measurement, employing techniques like overwriting the memory with a known value and analyzing the changed bit after running the program could prove more accurate than the techniques used in this work. Similarly, for the power consumption, an accurate measurement could have been achieved by running the algorithms on an isolated development board instead of measuring the power consumption at the module level. Despite these limitations, this research explores the practicability of lightweight encryption algorithms for enhancing security in communication between Digital Twins and the Industrial Internet of Things. Having in mind these limitations, in the next section, we present future directions for further improvement. ### Future Directions

Based on the insights gained from this work, the following future directions are proposed for further exploration:

**Optimizing ASCON for ESP32 Microprocessor Chip:** Different microprocessors have their own instruction architecture. Hence, future research work can be conducted on the optimization of lightweight encryption (ASCON) algorithms tailored for specific hardware devices, such as ESP32. This might involve identifying instructions that require fewer CPU cycles and replacing those instructions in the reference implementation that require more for the same operation. **Secure Remote Access for Resource-constrained Devices:** In addition to securing the communication channel of resource-constrained devices, it is essential to develop secure remote access control solutions tailored specifically for those devices in Industry 4.0 settings. As a future work, authenticated encryption with associated data (AEAD) lightweight algorithms can be further explored to provide secure remote access to sensors and actuators deployed in industrial zones. **Exploring Trade-offs Between Security and Performance:** Further exploration is needed to analyze the trade-offs between security and performance when implementing ASCON in resource-constrained IoT devices. This analysis will involve examining how different configurations impact security levels and operational efficiency. **User Study on Usability and User Experience:** Conducting a user study or survey to gather feedback on the usability and user experience of implementing ASCON in real-world Industry 4.0 applications should be considered. Incorporating user perspectives will provide insights into the practical implications and usability challenges of ASCON implementations. ## 8 Conclusions

In conclusion, our research addresses a critical void in the realm of security mechanisms designed for Digital Twin applications within Industry 4.0. The existing literature lacks in-depth discussions and recommendations for security solutions that can effectively balance the demands for both speed and security within the constraints of Industry 4.0's Digital Twin ecosystem, especially considering the limitations of IoT devices. To bridge this gap, our study introduced an innovative communication scheme utilizing the lightweight authenticated encryption with associated data (AEAD) algorithm, ASCON. This solution not only fulfills but surpasses crucial requirements for confidentiality, integrity, and authenticity while operating within the confines of resource limitations. A proof of concept involving the MQTT protocol validates the practicality of our approach, demonstrating its applicability in real-world scenarios. Moreover, our performance analysis, comparing ASCON to conventional AES (AES-GCM), unequivocally demonstrates the efficiency gains achieved in terms of speed, memory utilization, and power consumption, all while maintaining robust 128-bit security levels. This research makes a significant contribution by effectively addressing security challenges in Digital Twin applications for Industry 4.0, harmonizing with the unique constraints of sensor devices.