# Software Design and Experimental Evaluation of a Reduced AES for IoT Applications
## 5 Conclusions  
This paper presents a streamlined AES variant called LAES that employs a key whitening technique and operates on GF(2\({}^{4}\)). We evaluated and compared the operation of LEAS with three lightweight cryptographic algorithms: Celfia, Present, and AES. The evaluation was conducted using randomness analysis and time efficiency using six measures: the frequency (Monobit) test, the block test, the runs test, effective (total) encryption time, average encryption time for a single block, and average encryption time for a single round. The four algorithms were assessed with similar scenarios. The evaluation showed that LAES achieves comparable randomness to Celfia, Present, and AES for most scenarios in terms of randomness testing. The randomness average of LAES increases with relatively larger files; however, in terms of effective (total) encryption time, average encryption time for a single block, and average encryption time for a single round, the results for LEAS were clearly lower than those of Present and Celfia. This supports our objective to achieve high randomness levels with lower encryption time. The evaluation revealed outstanding improvements (i.e., reductions) in processing time and power consumption for LAES compared to Present, Clefia, and AES. Furthermore, LAES and its counterparts were evaluated and compared based on different measures using an 8-bit microcontroller Arduino Uno \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Measures**} & \multicolumn{3}{c}{**Cryptographic Algorithms (Block Size/Key Size/Number of Rounds)**} \\ \cline{2-5}  & **Present (64/128/31)** & **Clefia (128/128/18)** & **AES (128/128/10)** & **LAES (64/128/10)** \\ \hline Average block encryption time (us) & 3212 & 2846 & 4834 & 1920 \\ \hline Average number of CPU cycles for the block encryption & 51,392 & 45,536 & 77,344 & 30,720 \\ \hline Average round encryption time (us) & 103,613 & 158.11 & 483.40 & 120.23 \\ \hline Average number of CPU cycles per encryption round & 1658 & 2530 & 7734 & 1550 \\ \hline Average power consumption for block encryption (mWh) & 1.10189 \(\times\) 10\({}^{-4}\) & 9.80299 \(\times\) 10\({}^{-5}\) & 1.71876 \(\times\) 10\({}^{-4}\) & 6.37333 \(\times\) 10\({}^{-5}\) \\ \hline Average battery charge consumption for block encryption (mAh) & 2.20379 \(\times\) 10\({}^{-5}\) & 1.96058 \(\times\) 10\({}^{-5}\) & 3.43751 \(\times\) 10\({}^{-5}\) & 1.27467 \(\times\) 10\({}^{-5}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Evaluation outcomes based on the 8-bit microcontroller Arduino Uno board. board. LAES required fewer CPU cycles, less power, and less charge consumption for the block encryption. In future work, we plan to perform different cryptoanalysis techniques such as linear and differential attacks for LAES, and to evaluate its hardware implementation in order to measure its energy consumption and footprint compared to other well-known lightweight cryptographic algorithms. We also plan to implement the proposed LAES on hardware to evaluate the number of gates it requires and compare it with its counterparts. Another possible research direction will focus on evaluating LAES with different types of big data, including multimedia data such as audio and video. The proposed LAES will also be implemented and evaluated on real IoT applications that manipulate sensitive data, such as eHealth, smart homes and cities, tracking and surveillance, and location-based services applications. Conceptualization, M.Q. ; methodology, M.Q. and R.S.A.-Q. ; software, M.Q. and R.S.A.-Q. ; validation, M.A. and M.Q. ; formal analysis, M.Q. and M.A; investigation, R.S.A.-Q. and M.A. ; resources, M.Q. ; data curation, M.Q. and R.S.A.-Q. ; writing--original draft preparation, M.Q. and R.S.A.-Q. ; writing--review and editing, M.A. ; visualization, R.S.A.-Q. and M.A. ; supervision, M.Q. ; project administration, M.Q. and R.S.A.-Q. ; All authors have read and agreed to the published version of the manuscript. This research received no external funding.