协同制导防空中JTC和FrFT纯相位加密技术

Fully Phase Encryption Using the Joint Transform Correlator and Fractional Fourier Transformin Air-defense Combat of the Cooperative Control and Guidance

为了满足协同制导防空作战时,编队内各舰艇之间火控级的信息共享及数据传输,对协同制导防空作战通信时,在信息传输过程中可能用到的新技术,提出了基于联合变换相关器(joint transform correlator,JTC)和分数傅里叶变换(fractional Fourier transform,FrFT)的纯相位图像加密方法;加密时,首先将原始图像置乱后编码为相位函数,与相位掩膜相乘后和密钥分别放入联合变换相关器输入平面,成为待加密函数,经过α阶联合分数傅里叶透镜后在输出平面获得密文;解密时,先将密钥放在输入端,经过α阶分数傅里叶变换后与密文相乘,再经过-α阶联合分数傅里叶变换后得到包含原始图像的解密信息,提取其相位,经过反置乱后得到解密图像;数值仿真结果表明,该方法对密钥响应敏感,并有效地提高了解密图像质量、系统的安全性能和抗干扰能力。

In order to realize the fire control information sharing and data transmission among the war ships during the air--defense corn bat of the cooperative control and guidance, for the newtechnology that may be used in the air--defense combat of the cooperative control and guidance , a phase image encryption method based on the joint transform correlator （JTC） and fractional Fourier transform （FrFT） is pro posed. The original image is encoded into phase function after being scrambled, as the input signal. The encryption system based on JTC en- larged the key space and enhances the security, from Fourier domain to fractional Fourier domain by using fractional Fourier operators. The original image can be retrieved by using the correct key, the correct fractional order and pixel scrambling operators. The feasibility of the pro- posed eneryption method is proved by numerical simulations.