Virtex-7 FPGA Realization of AES-256 with Enhanced SubBytes and Key Schedule Performance

With the rising need for secure and efficient cryptographic solutions, especially in embedded and real-time systems, hardware-level enhancements have become increasingly important. This study presents a refined version of the AES-256 encryption algorithm, specifically adapted for resource-constrained environments where performance and energy efficiency are essential. By transitioning from the traditional 128-bit block structure to a 32-bit block framework, the design reduces computational demands while preserving the strong security features of AES-256. This modification supports a more modular and compact implementation, making it ideal for applications with limited hardware capabilities. Key optimizations include reusing S-box components and simplifying key table operations, which significantly lower logical complexity. Additionally, the use of pipelining improves data processing speeds while keeping latency under control. These design choices make the approach especially suitable for secure Internet of Things (IoT) devices, mobile gadgets, and compact communication modules. When implemented on the Xilinx Virtex-7 FPGA, the architecture demonstrates notable reductions in power usage and hardware resource consumption. This includes substantial savings in slice registers, LUTs, and LUT-FF pairs, along with a measurable increase in data throughput. the optimized AES-256 model offers a scalable and energy-conscious solution for modern cryptographic hardware implementations.