  In this paper, we propose an image encryption algorithm based on the chaos,
substitution boxes, nonlinear transformation in Galois field and Latin square.
Initially, the dynamic S boxes are generated using Fisher Yates shuffle method
and piece wise linear chaotic map. The algorithm utilizes advantages of keyed
Latin square and transformation to substitute highly correlated digital images
and yield encrypted image with valued performance. The chaotic behavior is
achieved using Logistic map which is used to select one of thousand S boxes and
also decides the row and column of selected S box. The selected S box value is
transformed using nonlinear transformation. Along with the keyed Latin square
generated using a 256 bit external key, used to substitute secretly plain image
pixels in cipher block chaining mode. To further strengthen the security of
algorithm, round operation are applied to obtain final ciphered image. The
experimental results are performed to evaluate algorithm and the anticipated
algorithm is compared with a recent encryption scheme. The analyses demonstrate
algorithms effectiveness in providing high security to digital media.
