强散射过程与双随机相位加密过程的等价性分析  

Equivalence analysis of highly scattering process and double random phase encryption process

作　　者：陈洁 周昕[1] 白星 李聪 徐昭 倪洋 Chen Jie;Zhou Xin;Bai Xing;Li Cong;Xu Zhao;Ni Yang(College of Electronic and Information,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学电子信息学院,成都610065

出　　处：《物理学报》2021年第13期73-79,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61475104,61177009)资助的课题.

摘　　要：薄层强散射介质的散射系统只会引起入射光波的振幅和相位分布变化,但不会导致总能量的衰减.这一过程可以看成光波被散射系统编码的过程,与双随机加密系统极为相似.本文首先证明了载有目标信息的光波在通过薄层强散射介质的散射系统时所产生散斑的分布特性,与双随机加密系统加密同一明文目标所得到的密文分布特性具有高度的相似性.然后,本文将该散射系统视为一个双随机加密系统,并利用相位恢复算法精确地计算出该散射系统所对应的两块随机相位密钥,同时证明了这两块密钥板还可以成功地从该散射系统所得到的其他任何散斑中恢复出对应的原始图像.最后,为了进一步证明二者的等价性,本文使用一种适用于双随机加密系统的唯密文攻击方法,成功地破解了薄层强散射介质的散射系统,得到了较好结果.The scattering system through a highly scattering thin layer only affects the amplitude and phase distribution of incident light wave,but does not lead the total energy to be attenuated.This process can be regarded as a process that light wave is encoded by the scattering medium,which is similar to a double random phase encryption system.In this paper,firstly,it is proved that the distribution characteristics of speckle generated by the light wave carrying the target information through a strongly scattering thin layer are highly similar to the distribution characteristics of cyphertext obtained by the double random phase encryption system encrypting the same plaintext target.Therefore,the scattering system is seen as a double random phase encryption system,and the two random phase keys corresponding to the scattering system are calculated accurately by using the phase recovery algorithm.At the same time,it is proved that these two key boards can successfully reconstruct the original images corresponding to any other speckles obtained by the scattering system.Finally,a cyphertext-only attack method to attack a scattering system through a highly scattering thin layer is used to further prove the equivalence of two key boards and the good results are obtained.Since imaging through a scattering medium is an extremely complicated process,we actually simplify the corresponding process ideally.It should be noted that the equivalent system means that the incident-surface-to-exit-surface of scattering medium is equivalent to the incident-surface-to-exit-surface of DRPE system.However,in the actual process,there are still two diffraction processes:one is the diffraction process from the object to the incident surface and the other is the diffraction process from the output surface to the receiving surface.These two diffraction processes will cause the incident image and the output image of scattering medium to have a certain diffraction effect.We believe that under ideal conditions,due to the equivalence between the thin-

关 键 词：强散射介质系统 双随机加密系统 相位恢复算法 图像重建 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]