In our digital world, the transmission of images between people has played an essential part in everyday communication. As a result, procedures to ensure the integrity and accuracy of the communicated data are required. Today, hashing is the most popular and secure way. This article focuses on the SHA-3 for hashing images dimensions 256 × 256 pixels with our custom implementations on the FPGA based on the Very High Speed Integrated Circuit Hardware Description Language (VHDL). We perform our experiments on the Intel Arria 10 GX FPGA and the Nios II processor. Also, our experiments with calculating metrics such as entropy, NPCR and UACI show that the SHA-3 is secure, reliable and has high application potential for hashing images. We propose designs to improve throughput, security, and efficiency criteria. We strengthened our design using the IP Block Floating Point Hardware 2 (FPH-2). Our experiments with the proposed implementation have shown increased throughput by 14.38% and efficiency by 13.95% of the SHA-3 algorithm. Finally, we compared our findings to other researchers' existing optimization methodologies, giving data that demonstrate our research's strengths.