imageEncryption

image encryption using Chaotic sequence and LFSR method based on the paper " Image encryption and decryption using chaotic key sequence generated by sequence of logistic map and sequence of states of Linear Feedback Shift Register " by " ROHITH S, K N HARI BHAT, A NANDINI SHARMA"

 1. LFSR

this method starts with an arbitrary seed and next number generates as shown in this figure

<p align="center"><img src="LFSR.png"></p> below is result of using this method <p align="center"> <img src="peppers.png"> <img src="LFSREnc.png"> </p> 2. Chaotic Sequence this method also starts with an arbitrary seed and another parameter mu. the formula that generates the next number is : X(i) = mu * x(i-1) * (1 – x(i-1)) <p align="center"><X(i) = mu * x(i-1) * (1 – x(i-1))></p> In this formula mu is between 2 and 4 and when is near to 4 the function generates highly random numbers. Here is how the function behaves <p align="center"><img align="center" src="chaotic.png"></p> <p align="center"><img align="center" src="peppers.png"> <img align="center" src="chaoticEnc.png"></p>

to make the encryption more secure the encryption key is combination of these two methods.

Encryption and Decryption : after generating keys using methods above:

encryptedImage = originalImage XOR Key <br/> decryptedImage = encryptedImage XOR key