On the basis of fractional wavelet transform, we propose a new method called cascaded fractional wavelet transform to encrypt images. It has the virtues of fractional Fourier transform and wavelet transform. Fractiona...On the basis of fractional wavelet transform, we propose a new method called cascaded fractional wavelet transform to encrypt images. It has the virtues of fractional Fourier transform and wavelet transform. Fractional orders, standard focal lengths and scaling factors are its keys. Multistage fractional Fourier transforms can add the keys easily and strengthen information se-curity. This method can also realize partial encryption just as wavelet transform and fractional wavelet transform. Optical reali-zation of encryption and decryption is proposed. Computer simulations confirmed its possibility.展开更多
We propose a novel method for image encryption,which is realized by the Collins formula with the random shifting method.The Collins formula can denote different optical transforms by one expression with different ABCD...We propose a novel method for image encryption,which is realized by the Collins formula with the random shifting method.The Collins formula can denote different optical transforms by one expression with different ABCD elements.For a generalized optical system,the ABCD elements can be randomly chosen,so the keys are increased and the security of the system is strengthened.Finally,some computer simulations are given for different encryption systems to prove the possibilities.The encryption effect is good,and people without the correct keys can not obtain the information easily.展开更多
基金Project (No. 10276034) supported by the National Natural ScienceFoundation of China
文摘On the basis of fractional wavelet transform, we propose a new method called cascaded fractional wavelet transform to encrypt images. It has the virtues of fractional Fourier transform and wavelet transform. Fractional orders, standard focal lengths and scaling factors are its keys. Multistage fractional Fourier transforms can add the keys easily and strengthen information se-curity. This method can also realize partial encryption just as wavelet transform and fractional wavelet transform. Optical reali-zation of encryption and decryption is proposed. Computer simulations confirmed its possibility.
基金the National Natural Science Foundation of China under Grant No 11147138the Natural Science Foundation Zhejiang Province under Grant Nos LQ12A04001 and R1090168the Natural Science Foundation of Educational Department of Zhejiang Province under Grant No Y200908864.
文摘We propose a novel method for image encryption,which is realized by the Collins formula with the random shifting method.The Collins formula can denote different optical transforms by one expression with different ABCD elements.For a generalized optical system,the ABCD elements can be randomly chosen,so the keys are increased and the security of the system is strengthened.Finally,some computer simulations are given for different encryption systems to prove the possibilities.The encryption effect is good,and people without the correct keys can not obtain the information easily.
