Article’s

Abstract—Abstract—Smartphones have increasingly become the primary platforms for storing sensitive personal and professional data. However, many existing storage solutions do not provide sufficient privacy protection. Cloud-based services offer convenience, but they introduce risks such as unauthorized access and exposure to third-party data handling. Likewise, several on-device vault applications rely on weak or non-standard encryption methods, making them susceptible to compromise using common forensic tools.To address these challenges, this work presents SecureVault, an Android application designed with strong cryptographic foundations and layered authentication mechanisms. The application secures all stored data, including images, videos, audio, and documents, using AES-256 encryption. In addition, it supports both PIN-based and biometric authentication for enhanced access control. By operating entirely on-device without reliance on cloud services, SecureVault minimizes potential security vulnerabilities and significantly reduces the overall attack surface. Our evaluation on real Android hardware showed that the system achieves strong security guarantees while keeping encryption overhead low enough for practical daily use. We also outline planned extensions, including optional encrypted cloud backup, AI-driven anomaly detection, and intrusion lockout mechanisms. Keywords—AES-256 encryption, Android security, secure local storage, biometric authentication, data privacy, mobile application security