Penerapan Advanced Encryption Standard Pada Aplikasi Payment Gateway Untuk Keamanan Data Transaksi Penjualan

Data security in membership sales transactions is crucial for protecting customer privacy and enhancing trust in the system, especially in an increasingly complex digital era. This research aims to develop a membership sales application
for Brothersgym Bengkalis by implementing the Advanced Encryption Standard (AES) CBC 128-bit algorithm and integrating a payment gateway. The application development follows the Waterfall method, which includes requirement analysis, design, implementation, and testing. The AES CBC 128-bit algorithm is applied to encrypt sensitive data, such as payment_va_name and payment_va_number, stored in the database, ensuring protection from unauthorized access. The system is tested using white-box testing for application functionality and a brute-force key attack simulation using Cryptool. Test results show that the AES CBC 128-bit algorithm provides strong protection against data security threats in membership sales transactions, while the Midtrans payment gateway enables efficient and secure online transactions. This research results in a secure, efficient application integrated with a payment gateway, offering a significant solution for protecting membership sales transaction data and boosting customer trust in Brothersgym's online services.