image encryption using rc4 : error in bitxor

Hello Community ,

i work now on rc4 image encryption algorithm but i am facing a little proplem

the image dimensions is 128 * 128 uint8

& the cipher generated by my algorithm is 1 * 128 uint 8

how to get the cipher to be generated in the same dimensions of input image

i will attach compressed file contains algorithm files

Hope you can help me, Thanks in Advance

[DGM]

What is image2data()? Is it this? If so, the output is a handle to a figure object, not an image.

[Muhammad Abdulrazek]

No sir , it is not image2data which get curve data from image

image2data is a function from qpsk modulator package

Answer 1

[Jan]

You instruct PRGA to reply 128 values:

Cipher = uint8(PRGA(KSA(key), size(original,2)));

I assume you want:

Cipher = uint8(PRGA(KSA(key), numel(original)));

[Muhammad Abdulrazek]

@Jan

Thank you very much , it work

but i have another problem : the image after encryption & decryption doesnt apear in figure or histogram ?

[Jan]

It does appear: Do you see the blue lines at x==0 and x==1? This seems to be a confusion between the double and UINT8 types. Cast the images as UINT8 before you forward it to the function to compute the histograms.

[Muhammad Abdulrazek]

Thank you , I solved ther other problem