# Energy Consumption Analysis of ISO/IEC 29192-2 Standard Lightweight Ciphers
## 4 Test Environment, Scenario, and Results
### Test Scenario  
The mission of edge computing embedded devices involves processing data from sensors according to the specific purpose of the IoT application, then either transmitting these data to cloud, server, or broker devices, or executing various operations on the sensor based on the received data. Data are typically transmitted unencrypted via communication protocols like MQTT and CoAP. Data must be encrypted before being sent in order to ensure a secure connection, and they should be sent afterward [27]. The test scenario illustrated in Figures 3 and 4 demonstrates the encryption and decryption process of 1 KB data using the selected lightweight cryptographic algorithms. The MSP430 FR5994 edge device initiates the process by transitioning from low-power mode (LPM) to active mode (AM). During this phase, the device performs either encryption or decryption, following a structured sequence that involves key scheduling and the cryptographic operations. To enhance transparency and reproducibility, pseudocode representations of the CLEFIA, PRESENT, and LEA implementations used in this scenario are provided in Appendix B. Since energy measurements are cumulative, a 1 KB fixed data block provides a measurable and meaningful workload for evaluating encryption algorithms without excessive computational overhead. To improve measurability and ensure consistency with previous experiments, a fixed 1 KB data size was selected. The input plaintext (1 KB) is processed by the encryption algorithm, resulting in a 1 KB ciphertext. Conversely, in decryption mode, the ciphertext is restored to its original plaintext form following the same structured process. To accurately evaluate the runtime, energy consumption, and current usage of each algorithm, the EnergyTrace tool is run. As shown in Figure 4, EnergyTrace initiates at the start of the encryption/decryption process and terminates at the end of the operation, ensuring that the power consumption measurements reflect only the cryptographic processing stage. This allows for a precise assessment of the energy efficiency of different lightweight encryption algorithms within the scope of ISO/IEC 29192-2. Additionally, to optimize power consumption, the device automatically switches back to low-power mode (LPM) once the encryption or decryption process is completed. If the device remains inactive between operations, it conserves energy by staying in LPM until the next encryption/decryption request is triggered. This behavior closely aligns with real-world IoT applications, where devices frequently alternate between active computation and idle states to prolong battery  
Figure 3: Test scenario for energy measurement of ISO/IEC 29192-2 algorithms. life. The test scenario provides a controlled and repeatable environment for analyzing the performance of the encryption algorithms while considering practical constraints such as power consumption and execution time. By leveraging MSP430 FR5994's ultra-low-power capabilities and the EnergyTrace tool, this setup ensures reliable benchmarking of the cryptographic algorithms under ideal conditions, minimizing the influence of external factors such as network delays or sensor noise. This study is limited to the evaluation of encryption and decryption energy consumption under ideal and controlled test conditions. While the experimental scenario was designed to reflect typical trends observed in real-world IoT applications, it does not account for external factors such as temperature fluctuations, network latency, or real-time data transmission. These variables may influence the overall energy behavior of the devices in actual deployments. However, the use of a controlled test environment enables an isolated and objective comparison of algorithmic performance, focusing purely on the computational characteristics of the encryption algorithms. Additionally, the study was conducted using a single hardware platform, the MSP430 FR5994, which was selected for its low-power features and advanced energy profiling capabilities.