Comparison of Public Key Algorithms for Lightweight and Low Cost System

As resource-constrained devices such as RFID and smart cards are being widely developed and used, there is an increase in the need for an efficient lightweight cryptographic algorithm. Elliptic Curve Cryptography is one type of public key cryptography which provides the same level of security when compared to RSA, with a smaller key size. Hence, ECC has many advantages like less area, less power consumption, and high performance. This paper proposes a processor for ECC over Galois field (2¹⁶³) for low-cost systems where the main focus is on scalar point multiplication operation. An RSA crypto processor is also implemented to compare the area occupied by the two processors. This is done using Verilog programming in Xilinx Virtex 4 and Virtex 7 series. Simulation is also done for ECC over GF (2²³³). The simulation and synthesis results show that the ECC crypto processor occupies lesser slices compared to 1024 bit RSA crypto processor in order to achieve the same level of security. It is also proved that the number of slices occupied for ECC 163 bits in Virtex 4 series is much lesser compared to Virtex 7 series. Therefore, it is easy to accomplish compact and faster designs in ECC crypto processor that can be applied to low-cost systems.

I. Introduction

Communication technology has evolved leaps and bounds over the years. From written letters to telephone operators manually connecting the calls to mobile phones and video calling, the development has been nothing short of tremendous. But with the advent of these innovations, the vulnerability of the users to an invasion of privacy has also increased. Thus, the need to have secure and reliable forms of communication is now a need more than ever. Cryptography plays a vital role in communications because it not only helps in secure transmission of data, but also ensures the integrity and authentication of messages. Due to the resource, computing, and environmental constraints, the efficient implementation of cryptographic protocols is a challenging task. Cryptography consists of two types, public key cryptography and symmetric key cryptography. Symmetric key cryptography is a type of cryptography in which the same key is used for encryption as well as decryption. Public key cryptography is a type of cryptography that uses two keys, namely public key and private key where the public key is known to all and private key is kept as secret. Lightweight cryptographic algorithm is used to ensure security in low cost systems like RFID, smart cards, sensors as they are resource constrained devices. In the past years, there has been a tremendous increase in the usage of these low cost systems. Multitude of low cost systems have reached the consumer level. Data threats and security risks associated with it also rises. Instead of conventional cryptographic algorithms, lightweight algorithms must be applied as they utilize only a small amount of gate equivalents.