**3. Implementation of AES algorithm**

*Computer and Network Security*

In this section, focus is given on the work done by various researchers on FPGAbased implementation of AES algorithm. There are various researchers which have either concentrated on area optimization or speed optimization. Mulani and Mane [1] discussed integrating of DWT and AES algorithm for implementation of watermarking on FPGA. The design was implemented on xc6vcx75t-2ff484, and it utilizes 2117 slices at maximum operating frequency of 228.064 MHz. Ratheesh and Narayanan [2] proposed implementation of AES algorithm with low-power MUX LUT-based s-box on FPGA. This design achieved total power distribution of 0.55 W. Agarwal et al. [3] suggested implementation of AES algorithm using Verilog on Spartan-3E FPGA. This design utilizes 1464 slices. Farooq and Faisal Aslam [4] discussed implementation of AES algorithm on FPGA device using five different techniques which are suitable for area critical applications and speed critical applications. This design was implemented on Spartan-6 FPGA device, and it utilizes 161 slices at maximum operating frequency which is 886.64 MHz. The throughput of this system is 113.5 Gbps. Sai Srinivas and Akramuddin [5] proposed less complex hardware implementation of AES Rijndael algorithm on Xilinx Virtex-7 XC7VX90T FPGA. In the proposed design, synthesis tool was set to optimize speed, area, and power. Mathur and Bansode [6] proposed a cryptosystem, which is a combination of AES algorithm and ECC. This is a hybrid encryption scheme and the key size is 192 bits and there are 12 numbers of iterations in this system. Kalaiselvi and Mangalam [7] proposed a low-power and high-throughput FPGA implementation of AES algorithm using key expansion technique. This design accepts key size of 256 bits for both encryption and decryption. This design utilizes 5493 slices, and its maximum operating frequency is 277.4 MHz. The throughput of this system is 0.06 Gbps. Deshpande et al. [8] suggested BRAM-based and FPGA-based implementation of AES algorithm. Due to the use of BRAMs for implementing s-box, this design utilizes less number of slices. The design was implemented on XC3S1400AN and it utilizes 3376 slices. Ibrahim [9] presented FPGA implementation of AES encryption core that is suitable for limited resource-limited applications. This design was implemented on Spartan-3, and it utilizes 150 slices at maximum operating frequency of 90 MHz. Khose and Raut [10] proposed implementation of AES algorithm on FPGA in order to achieve high speed of data processing and also to reduce time for generating key. This design utilizes 201 slices and 2 BRAMs at maximum operating frequency of 70 MHz. Mulani and Mane [11] proposed FPGA implementation of DES algorithm. The design was implemented on XC2S200, and it utilizes 2118 slices and 97 IOBs. Yewale Minal and Sayyad [12] proposed implementation of AES encryption using VHSIC hardware description language VHDL) and decryption using Visual Basic. With this approach, 1403 slices are utilized at maximum operating frequency of 160.875 MHz, and it has a throughput of 2.059 Gbps. Deshpande et al. [13] discussed FPGA-based optimized architecture that utilizes less area. This design was intended for plaintext of 128 bits and key of 128 bits. Tonde and Dhande [14] discussed FPGA-based implementation of AES algorithm using iterative looping approach for 128 bits of block and key size. Varhade and Kasat [15] proposed a FPGA-based AES algorithm, which utilizes 1746 logic elements and 32,768 memory bits. This design was synthesized on Cyclone-II using Altera. Wadi and Zainal [16] proposed some modifications like decreasing number of rounds and replacing S-box with new s-box to reduce hardware requirements in order to enhance the performance of AES algorithm in terms of time ciphering and pattern appearance. Wang et al. [17] suggested high-speed implementation of AES algorithm on FPGA to transmit the data securely using pipelining and parallel processing methods. Shylashree et al. [18] focused on various novel FPGA architectures of AES algorithm. Borkar et al. [19] proposed iterative design approach for FPGA implementation

**2. Literature survey**

**124**

The proposed design is implemented with the aim to achieve both area and speed optimization. In the proposed design, keys for each round are initially generated by using MATLAB code, and then those keys are used in the design. Due to this approach, the design occupies less number of slices, and also the speed is faster than the normal approach. The design is implemented using Xilinx system generator. **Figure 9** shows Xilinx system generator-based model for AES algorithm.

**Figure 9.** *System generator model for AES algorithm.*
