Known-plaintext attack on cryptosystem based on fractional Hartley transform using particle swarm optimization algorithm

Abstract

Known-plaintext attack based on particle swarm optimization algorithm is mounted successfully on an image encryption scheme that uses single-fractional Hartley transform. The results point out that the proposed algorithm successfully retrieved the fractional orders of the transform, which forms the secret keys. Robustness of the algorithm is tested on noisy and missing data encrypted images. The secret keys are successfully retrieved in the presence of Gaussian noise of considerable strength. This study brings out the success of particle swarm optimization algorithm in mounting known-plaintext attack on an optical image encryption scheme in fractional Hartley domain.