(IJACSA) International Journal of Advanced Computer Science and Applications, Vol. 11, No. 9, 2020 117 | Page www.ijacsa.thesai.org High-Speed and Secure Elliptic Curve Cryptosystem for Multimedia Applications Mohammad Alkhatib College of Computer and Information Sciences Al Imam Mohammad Ibn Saud Islamic University (IMSIU) Riyadh, Saudi Arabia Abstract—The last few years witnessed a rapid increase in the use of multimedia applications, which led to an explosion in the amount of data sent over communication networks. Therefore, it has become necessary to find an effective security solution that preserves the confidentiality of such enormous amount of data sent through unsecure network channels and, at the same time, meets the performance requirements for applications that process the data. This research introduces a high-speed and secure elliptic curve cryptosystem (ECC) appropriate for multimedia security. The proposed ECC improves the performance of data encryption process by accelerating the scaler multiplication operation, while strengthening the immunity of the cryptosystem against side channel attacks. The speed of the encryption process has been increased via the parallel implementation of ECC computations in both the upper scaler multiplication level and the lower point operations level. To accomplish this, modified version of the Right to Left binary algorithm as well as eight parallel multipliers (PM) were used to allow parallel implementation for point doubling and addition. Moreover, projective coordinates systems were used to remove the time-consuming inversion operation. The current 8-PM Montgomery ECC achieves higher performance level compared to previous ECC implementations, and can reduce the risk of side channel attacks. In addition, current research work provides performance and resources-consumption analysis for Weierstrass and Montgomery elliptic curve representations over prime field. However, the proposed ECC implementation consumes more resources. Presented ECCs were implemented using VHDL, and synthesized using the Xilinx tool with target FPGA. Keywords—Elliptic curves cryptosystem; performance; binary method; projective coordinates; security applications LIST OF NOTATIONS ECC Elliptic Curve Cryptosystem RLA Right to Lift Algorithm SPA Simple Power Attack STA Simple Time Attack SM Sequential Multiplication SA Sequential Addition PM Parallel Multiplier TSM Time-consumption for one sequential multiplication TM Time-consumption for one multiplication operation TKP Time-consumption for scaler multiplication GF Galious Field NAF Non-Adjacent-Form I. INTRODUCTION Elliptic Curve Crypto-system (ECC) is a type of public key cryptosystems that depend on the discrete logarithm problem for elliptic curves. It has been introduced by Miller and Koblitz in 1985 [1,2]. Since that date, it has been widely used in many security applications due to its reliability and efficiency. By using much shorter key length, ECC can provide equivalent security level to that obtained by other asymmetric ciphers such with consuming less time and resources, which made it very efficient for multimedia applications that need to provide the security services for huge amount of data in the shortest possible period of time and, of course, with the least amount of resources consumed. A variety of ECC representations over GF(p) and GF (2 n ) were presented and used for different elliptic curves applications. First, ECC represents the paintext as a point on an elliptic curve. Then, it encrypts the plaintext by performing a number of arithmetic operations over finite fields. ECC computations can be categorized into upper and lower layers. The upper layer’s computations are mainly point doubling and point addition operations, which are performed by the scaler multiplication operation. It is worth mentioning here that the scaler multiplication is the key operation in ECC encryption process. On the other hand, lower level of computations includes addition, multiplication, and inversion operations. The latter is the most time-consuming operation [3]. Previous research works focused on improving the performance and security of ECC encryption. These works studied several possible techniques to accelerate the encryption process by speeding up scaler multiplication operation as well as increasing the cryptosystem immunity against side channel attacks such as simple time (STA) and simple power (SPA) attacks. The major performance improvement techniques include the use of projective coordinates to avoid the costly inversion operation and the parallel implementation of ECC arithmetic computations, especially in the lower level [1-5]. The current research utilizes both the use of projective coordinates and the inherited parallelism in ECC computations, and perform these computations in parallel for both upper and lower computational layers. This is achieved by using parallel hardware components, which are multipliers and adders. In addition to performing the lower level computations in parallel, this study implements the upper layer’s operations in parallel to achieve higher speed for encryption process. In particular, proposed ECC performs the two main operations (point