Jurnal Media Informasi Teknologi

Vigenere Cipher Cryptography for Secure Data Transmission in IoT Smart Door Using QR Code

Riski Arasyid, Syamsul Bahri , Kasliono — Wed, 01 Apr 2026 00:00:00 +0000

The Smart Door system based on the Internet of Things (IoT) using QR Code offers automated access but remains vulnerable to data sniffing attacks. This study implements the Vigenère Cipher algorithm to encrypt transmitted data and analyzes the ciphertext's resistance to attacks as well as its impact on communication delay. The system is built using ESP32-CAM as the QR scanner and NodeMCU ESP32 as the main controller, with encryption applied across three communication paths: ESP32-CAM to server, server to database, and server to ESP32. Testing involved data sniffing, delay analysis, and ciphertext evaluation using tools such as dCode and CryptoTool. From 20 sniffed QR Code results, 10 random samples were tested, and only 3 were recognized as Vigenère Cipher and none were decrypted successfully. In the server-to-ESP32 path, only 1 out of 10 ciphertexts was detected and all remained undeciphered. The average delay was recorded at 2.473 seconds (door unlocking) and 3.491 seconds (buzzer activation), with variations due to network stability. The results indicate that Vigenère Cipher effectively enhances data security in resource-constrained IoT devices, although delay optimization is needed to meet real-time system requirements.

Assessment of Internet Service Quality on Campus and Its Impact on Student Satisfaction

Ahmad Faris Al Faridzin, Andi Muhammad Nur Hidayat — Sun, 07 Jun 2026 00:00:00 +0000

Internet service quality plays an important role in supporting digital-based academic activities in higher education, including online learning, access to scientific journals, and academic communication. However, students still frequently experience network problems such as slow and unstable connections, high latency, jitter, and packet loss, which may affect the effectiveness of the learning process. This study aims to evaluate the quality of campus internet services based on Quality of Service (QoS) parameters and analyze their relationship with student satisfaction toward campus internet services. The study employed a quantitative approach using observation and survey methods. QoS measurements were conducted using Speedtest and Pingtest at several campus locations during peak and non-peak hours, while student satisfaction data were collected through an online survey involving 120 respondents. The data were analyzed using descriptive analysis and Pearson correlation analysis. The results showed that internet network quality decreased during peak hours, indicated by lower internet speed and higher latency, jitter, and packet loss. The survey results also revealed that most students were still dissatisfied with the quality of campus internet services. Correlation analysis indicated that internet speed had a positive relationship with student satisfaction, while latency, jitter, and packet loss had negative relationships with user satisfaction levels. Based on the findings, increasing bandwidth capacity, adding Wi-Fi access points, and conducting regular network maintenance are necessary to improve the quality of campus internet services.

Implementation of Cryptography using the Rivest Cipher (RC4) Algorithm on QR Code Security for E-Locker Verification

Abang Muhammad Sayudi Hamzah, Uray Ristian, Kasliono — Wed, 22 Jul 2026 00:00:00 +0000

The Internet of Things (IoT) based E-Locker system with QR Code authentication offers ease of access, but is vulnerable to threats to the security of Universally Unique Identifier (UUID) data on locker access. This study aims to implement cryptography with the Rivest Cipher 4 (RC4) algorithm to secure UUID data on the server and determine the authentication time on the QR Code barcode to the ESP32-CAM. The RC4 algorithm uses a static key for the user. The encryption process is carried out by the Mobile with the KSA, PGRA and Base64 processes to produce ciphertext. The decryption process is carried out by the server through the Base64, KSA and PGRA processes to produce Plaintext. The test results on the RC4 UUID algorithm stored in the database are sent to the Mobile for encryption and decryption processes where QR Code authentication to the ESP32-CAM sends data to the server for data validation if successful it sends back a notification to the Buzzer once, if it fails it sounds twice. The results of the security test, sniffing was successful using the original UUID data converted to a QR Code barcode and the QR Code was authenticated to the ESP32-CAM so that it produced 2 sounds on the buzzer so that the locker access failed. The data used for authentication was 40 data from each user authenticated 10 times, with the lowest authentication time of 2.83 seconds, the longest authentication time of 12.41 seconds, and an average time of 5.42 seconds.

Implementation of Event-Driven Architecture in Soil Moisture Sensor Data Transmission Based on Master–Slave

Sat, 01 Aug 2026 00:00:00 +0000

The decline in chili crop productivity is partly caused by Soil Moisture that is not properly monitored. Manual monitoring is considered less effective, while IoT systems with periodic data transmission tend to be inefficient. This study develops a Soil Moisture monitoring system based on an Event-Driven master–slave architecture using four ESP32 devices. Three act as slaves connected to Soil Moisture sensors, and one serves as the master responsible for data transmission. The Event-Driven method applies two mechanisms: Batch Update every 5 minutes under normal conditions and Immediate Alert when moisture values fall outside the ideal range of 50–70%. System performance is compared with a non-Event-Driven method based on QoS parameters: delay, jitter, payload, and the number of data packets. Testing is conducted through four scenarios, each lasting one hour. Results show that the Event-Driven system is more efficient. The average delay and jitter are 547.35 ms and 557.05 ms, lower than the non-Event-Driven system (3,340.73 ms and 1,755.71 ms). In addition, fewer packets are sent with larger payloads. Although it does not yet meet the TIPHON standard, this method can transmit data immediately during significant changes while reducing the number of transmitted packets.

Implementation of Failover in a Master-Slave Architecture for Soil Moisture Sensor Data Transmission

Ajeng Fitria, Uray Ristian, Syamsul Bahri, Ida Bagus Gede Sarasvananda — Sat, 01 Aug 2026 00:00:00 +0000

Development of Internet of Things (IoT) offers significant opportunities in the agricultural sector by enabling automatic and efficient monitoring of crop conditions. A common issue in IoT-based monitoring systems utilizing a master-slave architecture is the loss of data communication when the master node experiences a failure, which reduces system reliability. This research develops a plant monitoring system based on a master-slave architecture with a failover method using ESP32 and HTTP communication. The system consists of three master nodes, each handling two slave nodes, with a total of twelve soil moisture sensors. Data from the sensors are transmitted by the slave nodes to the master nodes, then forwarded to a cloud server. The failover method functions to maintain communication continuity by rerouting data transmission when a master node experiences a failure. The test results show that the system without failover experienced data loss and communication downtime equal to the duration of the master node failure, while the integration of IoT and failover method maintained communication with an average packet loss of 2.22% and a switching delay of approximately 0.78 seconds.