Research On Attack Methods Of Correlation Imaging Optical Encryption Technology

As the speed of information interaction continues to increase,the issue of how to ensure information security has become increasingly severe.Optical information security technology has become an important branch in the field of information security by virtue of its fast parallel processing and large capacity.Among them,as a new optical imaging technology,correlation imaging can encrypt two-dimensional image into one-dimensional data because of its data compression characteristics,which greatly reduces the amount of ciphertext data,so it is widely concerned by researchers.However,most researchers focus on improving the correlation imaging encryption system by combining methods such as cosine transform and Fourier transform,and there is little research on the security of the system itself.This paper studies the principle of the correlation imaging encryption system,analyzes its security,and proposes two methods of selective plaintext attack and forgery attack against the system.(1)This paper studies the chosen-plaintext attack method based on the correlation imaging encryption system and proposes three schemes in the chosen-plaintext attack.The first solution is choosing a linear independent matrix with real-valued elements as the plaintext,and form a linear equation set with the illumination template and detection data.The solution of the equation set by the linear least square method is the illumination template,and the illumination template is used as the decryption key to crack the encryption system.The second solution is choosing a series of random real-valued templates as the plaintext,because the feature that the lighting template and the plaintext image play the same role in the correlation imaging,the two roles could be exchanged,using the plaintext image to modulate the lighting template,and the lighting template restores by the correlation imaging technology,which is used as a decryption key cracking system.The third solution is choosing a series of images with only one pixel value of 1 and other pixel values of 0 as plaintext.The detection result now is the intensity value of the illumination template at each 1 pixel.Therefore,as long as the position of one pixel is moved in turn,all the original lighting templates can be obtained,and then the original plaintext image can be restored.The three chosen-plaintext attack schemes can successfully attack the correlation imaging encryption system,and the greater the number of plaintexts selected,the better the quality of the recovered plaintext image;but when decrypting the ciphertext,the lighting template is used as the decryption key instead of directly crack out the encryption key.On this basis,two enhanced schemes are also proposed to resist the above three chosen-plaintext attack methods.(2)A method of forgery attack is proposed.The attacker prepares a large number of random illumination templates and some fake plaintext images in advance,intercepts the ciphertext through the public channel,and then uses the prepared random illumination template to illuminate the fake plaintext images to obtain the corresponding detection sequence.When the binary result of the detection sequence is the same as the binary result of the intercepted ciphertext,the lighting template can be used as the forged key.If the attacker sends the forged key to the receiver,the receiver may use the forged key to decrypt the fake plaintext image and be deceived or confused.The results of numerical simulation and optical experiment also show that the attack method can successfully attack the correlation imaging encryption system.