Optical Hash Function Based On Interaction Between Multiple Scattering Media With Coherent Radiation

With the rapid development of computer and network technology,people can obtain and process all kinds of information flexibly and conveniently.When people enjoy the convenience brought by the development of technology,the following information security problems are more and more serious.Optical information security,as a new subject,has attracted more and more researchers’ attention due to its natural advantages such as high-speed parallel processing capabilities,large-capacity storage space,and multi-dimensional design freedom.The Hash function is an important branch in the field of information security.Its unique anti-collision and easy-to-calculate features make it widely used in digital signatures,data integrity detection,and identity authentication.In this paper,we will first introduce the research background and current situation of information security and optical information security,then summarize the basic concept and characteristics of Hash function,and finally propose the construction scheme of optical Hash function based on the interaction between multiple scattering medium with coherent radiation,including the Hash function which sensitive to the change of bit data and the Hash function which sensitive to the change of perceptual content but not sensitive to the change of non-perceptual content(In this paper,we only study the image Hash function).The main contributions of this paper are concluded as:(1)A construction scheme of an optical Hash function based on the interaction between multiple scattering media with coherent radiation is proposed.This scheme uses a opto-electronic device which is consisting of SLM(spatial light modulator),high-precision CCD,optical lens,multiple scattering medium,and computer to process the message and finally output a hash sequence.The multiple scattering media can confuse and diffuse the input data,thus providing security for the designed optical Hash function.(2)An image Hash function construction scheme based on the interaction between multiple scattering media with coherent radiation is proposed.In this scheme,coherent radiation waves modulated by image information interact with the multiple scattering medium to generate a speckle associated with the image.Further,a feature matrix is extracted from the speckle,and finally it is quantized and encoded to form the hash sequence.The multiple scattering medium can obfuscate and diffuse the input image,so as to provide security for the designed optical image Hash function.