Design and Performance Analysis of Secure Data Encryption Using the Advanced Encryption Standard (AES)

With the rapid growth of digital communication, cloud computing, and online data storage, ensuring data confidentiality and integrity has become a critical requirement in modern information systems. Cyber threats such as unauthorized access, data breaches, identity theft, and ransomware attacks highlight the urgent need for strong encryption mechanisms. The Advanced Encryption Standard (AES) is one of the most widely adopted symmetric key encryption algorithms used globally for securing sensitive information. This paper presents the design and implementation of a data security system based on the AES algorithm for protecting digital data during storage and transmission. The study explains the theoretical background of AES, including its substitution–permutation network structure, key expansion process, and encryption–decryption rounds. A practical implementation methodology is described, demonstrating secure file encryption and decryption using AES-128. The proposed system ensures high security, computational efficiency, and resistance against brute-force attacks. Experimental results confirm that AES provides strong encryption with minimal processing overhead, making it suitable for real-time applications. The findings emphasize that AES remains a reliable and robust cryptographic standard for securing modern digital systems.