Asymmetric Cryptographic Algorithm for Optical Images and Its Safety

摘要

Facing the increasingly serious network safety, the security of infomation encryption cannot be delayed to be improved. To enhance the sccurity of image encryption, vector transformation was used to separate an original image into two matrices based on the idea of asymmetric editing and Gyrator transfomation; one was served as a decryption key, and the other as a continued Gyrator transfomation. Then an asymmetric encryption structure was formed. A simulation test was performed to test the performance of the encryption algorithm and a correlation coefficient was introduced to determine the similarity of the decrypted image and the original one. The obtained simulation results suggest that the proposed encryption algorithm was able to encrypt Camera MAN images and recover the encrypted ones. The encrypted images could not be recovered in the abscncc of any decryption key. The proposed decryption key was so sensitive that even a small disturbance could make many useful image infomiation loss in the image decryption and can resist a chosen-plaintext attack. In conclusion, the asymmetric cryptographic algorithm based on vector decomposition and improved Gyrator transformation is reliable. The work offers a reference and assistance to the information encryption of optical images on the network.