# Latency-Aware Accelerator of SIMECK Lightweight Block Cipher
## 4 Implementation Results and Comparisons
### Results
_Designs running for specific to IoT devices._ As we have reported in Table 2, on Kintex-7, Virtex-7, and Artix-7 devices, (i) the utilized FPGA Slices are 51, 57, and 54, (ii) the used \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Device**} & \multicolumn{4}{c}{**Area Information**} & \multicolumn{4}{c}{**Timing Information**} & \multirow{2}{*}{**Power (mW)**} \\ \cline{2-2} \cline{4-11}  & **LUTs** & **Slices** & **FFs** & **DSP** & **CCs** & **PP (ns)** & **Freq (MHz)** & **Lat (\(\upmu\)s)** & **Thr ( Mbps)** \\ \hline \multicolumn{2}{c}{**Designs running at maximum operating frequencies**} & \multirow{2}{*}{\
\begin{tabular}{c} **Power (mW)** \\ \end{tabular} } \\ \hline Kintex-7 & 157 & 49 & 89 & 2 & 16 & 2.61 & 382 25 & 0.041 & 24.39 & 172.815 \\ \hline Virtex-7 & 162 & 51 & 89 & 2 & 16 & 2.63 & 379.50 & 0.042 & 23.80 & 179.864 \\ \hline Artix-7 & 164 & 50 & 89 & 2 & 16 & 2.57 & 388.52 & 0.041 & 24.39 & 189.777 \\ \hline \multicolumn{2}{c}{**Designs running for specific to IoT devices**} & \multirow{2}{*}{
\begin{tabular}{c} **Decisions running for specific to IoT devices** \\ \end{tabular} } \\ \hline Kintex-7 & 169 & 51 & 93 & 2 & 16 & 20 & 50 & 0.32 & 3.12 & 13.203 \\ \hline Virtex-7 & 171 & 57 & 93 & 2 & 16 & 20 & 50 & 0.32 & 3.12 & 13.651 \\ \hline Artix-7 & 175 & 54 & 93 & 2 & 16 & 20 & 50 & 0.32 & 3.12 & 14.745 \\ \hline \hline \end{tabular}  
* The IoT devices are composed of several elements such as sensors for data acquisition, data processing, control logic, memories for data storage, data transmission, and communication. The data processing is the dominant factor in power consumption. Consequently, power demand in Imote2 and MICAz commercial IoT networks are 170 mW [34; 35] and 53 mW [34]. Moreover, \(0-316\) mW power demand is stated for a commercial device of Imote2 processor radio (IPR2400) board with sensor (ITS400).  
\end{table} 
Table 2: Results after post-place-and-route for SIMECK32/64 over 7-series FPGA devices. LUTs are 169, 171, and 175. For all Kintex, Virtex, and Artix devices, the used FFs and DSP blocks are 93 and 2, respectively. The applications related to RFID, WSNs, WBANs, and IoTs demand limited power consumption for cryptographic computations. If we consider our architecture for these applications, power consumption is inadequate on higher circuit frequencies. Therefore, in Table 2, we provided power results of our architecture on the same circuit frequency of 50 MHz for Kintex-7, Virtex-7, and Artix-7 devices. As can be seen in Table 2, the consumed power of our SIMECK design is 13.203 mW (on Kintex-7), 13.651 mW (on Virtex-7), and 14.745 mW (on Artix-7). Now, on lower 50 MHz frequency, the latency value is increased (shown in column nine of Table 2). It is essential to mention that we provided our results only for Xilinx 7-series FPGA devices. The proposed SIMECK architecture can also be applied to other low-cost FPGA for use in RFID, WSNs, WBANs, and IoTs applications, not just for Xilinx products. It is evident from Table 2 that the optimal implementation is obtained for the Kintex-7 FPGA device where the least hardware resources in terms of Slices are utilized. The consumed power is also the lowest compared to the Artix-7 and Virtex-7 implementations. Moreover, the required time for one encryption and decryption computation is also the minimum. Consequently, the Kintex-7 implementations are more significant for area-constrained cryptographic applications where limited resources and higher computation speed is highly desired. Moreover, the Artix-7 and Virtex7 implementations are also good choices but with power overhead.