Implementasi Sistem Login Pada Aplikasi Pencatatan Transaksi Konter Pulsa Menggunakan Biometric Dan One Time Password

Credit counter businesses handle high volumes of daily transactions, yet many still rely on manual recording, which leads to data inaccuracies and financial monitoring difficulties. Furthermore, existing digital recording applications often use conventional authentication methods that are vulnerable to unauthorized access. This research aims to design and build an Android-based transaction recording application that implements a Multi-Factor Authentication (MFA) system using biometric authentication and One-Time Password (OTP). The application was developed using the Flutter Framework with the Dart programming language, utilizing Firebase for authentication and data storage. The proposed security system requires users to undergo three verification stages: password, a temporary OTP code, and the device's built-in biometric features (fingerprint or face recognition). The result of this research is the "Mudah Catat" application, which facilitates digital financial management and provides optimal protection for sensitive data against unauthorized use. System testing demonstrates that integrating biometrics and OTP successfully enhances security while maintaining efficiency for credit counter owners in managing their business finances digitally.