Elliptic curve based key generation for symmetric encryption

Abstract

With the explosion of networks and the huge amount of data transmitted along, securing data content is becoming more and more important. Data encryption is widely used to ensure security in open networks such as the internet. This paper presents the implementation of stream cipher, where the key stream is generated based on the properties of Linear Feedback Shift Register and cyclic Elliptic Curve over a finite prime field. In this paper we illustrate the process of encryption/decryption of an image in spatial domain and also encrypt key file parameters needed for generating the key stream to other parties using Elliptic Curve Cryptography. Therefore the encrypted key file parameters are only transmitted and not the entire full-length key. Since Elliptic Curve Cryptography is replacing RSA for key exchange and Elliptic Curve based stream cipher offers a good choice for encryption in real time application. The strength of the proposed cipher lies in the generation of random sequence using Linear Feedback Shift Register over GF(p), difficulty of Elliptic Curve Discrete Logarithmic Problem and the entire key need not be transmitted in the encryption process. This paper also discusses the security aspects of the proposed cipher which is secure against all kinds of attacks.