Digital color-image encryption scheme based on elliptic curve cryptography ElGamal encryption and 3D Lorenz map

Now a days, The security of digital data is an important task. In this paper, we propose a novel method of digital color-image encryption and decryption based on elliptic curve cryptography (ECC) ElGamal encryption and 3D Lorenz map. In this proposed method, we have applied ECC on the digital color-image, for this, a mapping method is proposed to convert the pixels of the image as points on the elliptic curve. Further, to enhance the security of the cryptosystem, a substitution method is applied in the intermediate image using the keystream generated by the 3D Lorenz map. The decryption method is the same but in reverse order. A mapping inverting method is proposed for the decryption to get the original image. The security and statistical analyses are done on various images and the experimental results show the robustness of the proposed method.