# Energy Consumption Framework and Analysis of Post-Quantum Key-Generation on Embedded Devices
## 6 Conclusions
### Future Work  
The recommendations above are qualified by further potential experimental work utilising this test platform and software to broaden its scope. This would enable a more comprehensive end-to-end study to be performed with more parameters and to understand the full impact of the transition to PQC compared to classical cryptographic techniques. The scope may be expanded in a number of suggested ways:  
* **Additional Hardware Platforms:** To use and compare more than one type of hardware, for example adding Raspberry Pi 4 and another standard Intel x86/AMD64 ISA platform for comparisons. The meter used (unmodified) can capture up to 20 V with currents up to 5 A. Devices with attached batteries (e.g., laptops) are not suitable for this exercise due to the need to capture live energy utilisation directly. * **Alternative Software Libraries:** To identify further suitable cryptographic libraries for comparative testing, other than OpenSSL. For example, exploring Bouncy Castle [49] and/or other potential PQC libraries as they become available. A challenge here will be ensuring comparable algorithm support and maturity across different libraries. Possible alternative sources can be found directly at asecuritssite [50], which is a cryptographic website with resources for researchers, hobbyists, and professionals in the area, including for post-quantum cryptography. * **Explore End-to-End Sessions:** To expand the study to a fuller E2E lifecycle measurement across a range of scenarios: 1. On-Network Key Exchange: Measure the bidirectional energy consumption of different PQC and traditional key exchange protocols including network communication. 2. Data Transfer: Quantify the energy cost of encrypting and transmitting datasets of varying sizes using the negotiated symmetric keys derived from both PQC and traditional key exchange mechanisms (also considering the cost of the required hardening to AES-256 for all applications that [PERSON]'s algorithm effectively mandates). 3. Digital Signatures: Evaluate the energy efficiency of generating and verifying digital signatures using standardised PQC algorithms (e.g., ML-DSA, SLH-DSA), comparing to traditional signature schemes. Isolating the energy cost of specific operations in an end-to-end scenario will be a key challenge in this potential future work. * **New Standards:** To incorporate the evolution of the standards, for example to include HQC testing once this has been finalised by the NIST [33] into a FIPS standard and is incorporated into OpenSSL and other cryptographic libraries. Additional work to evaluate this algorithm could be carried out upon its availability, even whilst in Beta testing. The experimental broadening proposed in this Future Work and how it impacts on the areas selected as the initial scope of this study is illustrated in Figure 6.  
A significant portion of the work for this paper involved investing time in developing a robust methodology for capturing energy utilisation data. The setup is outlined in more detail in Section 4.3. The framework was designed to allow this study to be extended in the future to other applications that utilise similar experimental setups. Having established energy efficiency differences in key generation, future research should examine if the patterns of the results persist across all operations and end-to-end encrypted communication protocols. Conceptualization, J.C.P. and W.J.B. ; software, J.C.P. ; validation, J.C.P., W.J.B. and C.T. ; formal analysis, J.C.P., W.J.B. and C.T. ; investigation, J.C.P., W.J.B. and C.T. ; resources, J.C.P. ; data curation, J.C.P. and W.J.B. ; writing--original draft preparation, J.C.P., W.J.B. and C.T. ; writing--review and editing, J.C.P., W.J.B. and C.T. ; supervision, W.J.B. All authors have read and agreed to the published version of the manuscript. This research received no external funding. The original data presented in the study are openly available in the project GitHub repository [40], along with the code used during the experimentation.