基于DSP的多媒体混沌加密算法的研究与应用

#define UART_BASE_ADDR 0x400400 #define THR *((int *)(UART_BASE_ADDR+0)) #define LSR *((int *)(UART_BASE_ADDR+5)) #define IMAGEWIDTH 256L #define IMAGEHEIGHT 128L #define DELAYTIME 512 #define quarterOfImage 32 #define halfOfImage 64 #define thirdOfImage 96 extern unsigned char dbImage[IMAGEWIDTH*IMAGEHEIGHT]; extern unsigned int step; extern unsigned char response[10]; //extern unsigned char dbTargetImage[IMAGEWIDTH*IMAGEHEIGHT]; //extern unsigned char dbDecryptionImage[IMAGEWIDTH*IMAGEHEIGHT]; int mi,mj; unsigned int m_nWork; unsigned char * restrict pImg; unsigned char mark; //用来标记是否是对图片的第一像素进行加密 1是 0否 //unsigned char Coder(unsigned char In, unsigned char clr,unsigned char EnOrDe,unsigned char path); unsigned char Coder(unsigned char In, unsigned char clr,unsigned char EnOrDe); unsigned char SendData(unsigned char * restrict pImage,unsigned char mark,unsigned int length); //加密程序 void Encryption(int nWidth,int nHeight) { pImg=dbImage; //只有是第0块数据时认为是加密的初始状态 if(0==step) mark = 1; #pragma MUST_ITERATE(128,128); for ( mj=0;mj<nHeight;mj++ ) { //if(40==mj) //{ // printf("Have encrypted the half of the picture!\n"); //} #pragma MUST_ITERATE(256,256); for ( mi=0;mi<nWidth;mi++,pImg++) { //(*pImg1)=(~(*pImg))&0x0ff; //是对图像的第一个像素进行加密 if(1==mark) { (*pImg)= Coder((*pImg),1,1); mark = 0; } //不是对图像的第一个像素进行加密 else (*pImg)= Coder((*pImg),0,1); } //图像加密到1/4,2/4,3/4时，向上位机发送图片 if((mj==quarterOfImage)||(mj==halfOfImage)||(mj==thirdOfImage)) { switch(mj) { case quarterOfImage: SendData(dbImage,0,8192); break; case halfOfImage: SendData(dbImage,1,8192); break; case thirdOfImage: SendData(dbImage,2,8192); break; } //wait(DELAYTIME); } } //图像加密结束时，向上位机发送图片 SendData(dbImage,3,8192); //wait(DELAYTIME); } //解密程序 void Decryption(int nWidth,int nHeight) { pImg=dbImage; //只有是第2块数据时认为是解密的初始状态 if(2==step) mark=1; #pragma MUST_ITERATE(128,128); for ( mj=0;mj<nHeight;mj++ ) { //if(40==mj) //{ // printf("Have decrypted the half of the picture!\n"); //} #pragma MUST_ITERATE(256,256); for ( mi=0;mi<nWidth;mi++,pImg++ ) { //(*pImg1)=(~(*pImg))&0x0ff; //是对图像的第一像素进行解密 if(1==mark) { (*pImg) = Coder((*pImg),1,0); mark = 0; } //不是对图像的第一像素进行解密 else (*pImg) = Coder((*pImg),0,0); } //图像解密到1/4,2/4,3/4时，向上位机发送图片 if((mj==quarterOfImage)||(mj==halfOfImage)||(mj==thirdOfImage)) { switch(mj) { case quarterOfImage: SendData(dbImage,0,8192); break; case halfOfImage: SendData(dbImage,1,8192); break; case thirdOfImage: SendData(dbImage,2,8192); break; } //wait(DELAYTIME); } } //图像解密结束时，向上位机发送图片 SendData(dbImage,3,8192); //wait(DELAYTIME); } ////////////////////////////////////////////////////////////// #define P 2551 #define M 32768 const unsigned int p1=9503, p2=16384,p3=22938; //原本p1=0.29,p2=0.50,p3=0.70,在这里把它们都扩大32168倍 const unsigned int c[5]={15,60,31,29}; //c1,c2,c3,c4 ////////////////////////////////////////////////////////////// //参数注释：In 要处理的像素 // clr 是否要清除原始数据 1清除 非1不清除 // EnOrDe 加密还是解密 1加密 非1解密 // path 选择哪一路进行处理 //unsigned char Coder(unsigned char In, unsigned char clr,unsigned char EnOrDe,unsigned char path) unsigned char Coder(unsigned char In, unsigned char clr,unsigned char EnOrDe) { unsigned char i; static unsigned char T[4]; // 4 level delay T[0]对应于e(n-1),以此类推 unsigned long Un; // unsigned char En; //加密后的数据 unsigned char Cn; //没有加密的数据或称原数据 //判断是加密还是解密 if(EnOrDe == 1) //加密 { Cn = In; } else //解密 { En = In; } //只有加密或者解密图片的第一个像素时clr才为1 if(clr == 1) { T[1] = T[2] = T[3] =0; if(EnOrDe == 1) //加密 { T[0] = En = Cn; return En; } else //解密 { T[0] = Cn = En; return Cn; } } //计算Un的值 #pragma MUST_ITERATE(4,4); for(Un=0,i=0;i<4;i++) { Un+=(unsigned long)c[i]*T[i]; //针对DSP结构所作的优化 } // Un=(unsigned long)c[0]*T[0]+(unsigned long)c[1]*T[1]+(unsigned long)c[2]*T[2]+(unsigned long)c[3]*T[3]; Un = (unsigned long)(Un%P)*13; //针对DSP结构所作的优化 // Un = Un; //tmp=Un/P; //将取模转换成除、乘、减各一次,但此种改动没有提高效率 //Un-=tmp*P; //Un = (unsigned long)Un*13; if(Un<p1) Un /= 37; else if(Un <= p2) Un = (Un - p1)/27; else if(Un <= p3) Un = (p3 - Un)/26; else Un = (M - Un)/38; if(EnOrDe == 1) En =0xff&(Cn + (unsigned char)(0xff&Un)); //En=_sadd(Cn,(unsigned char)(0xff&Un)); //优化：使用内部函数,但此种改动没有提高效率 else Cn =0xff&(En - (unsigned char)(0xff&Un)); //Cn=_ssub(En,(unsigned char)(0xff&Un)); //优化：使用内部函数,但此种改动没有提高效率 T[3] = T[2]; T[2] = T[1]; T[1] = T[0]; T[0] = En; if(EnOrDe == 1) return En; else return Cn; } //功能：向上位机发送阶段图片数据 //参数： // pImage 要发送数据的起始地址 // mark 由此标记来决定从数据块的哪个位置输送数据 0～3代表一块数据的第几片数据 4代表响应信息 // length 要传输数据的字节数 unsigned char SendData(unsigned char * restrict pImage,unsigned char mark,unsigned int length) { unsigned int index,initOffset; unsigned int uWork; //向上位机发送响应信息RIP:* if(mark==4) { #pragma MUST_ITERATE(5,5); for ( index=0;index<5;index++ ) { do { uWork=LSR; } while ( uWork&0x040 != 0x040 ); THR=*(pImage+index); //这个延时对于上位机很重要，太小就会使上位机接收混乱 wait(4); //wait(128); } return 0x01; } //向上位机发送图片数据信息 //计算从哪个位置将数据向上位机传输 switch(mark) { case 0: initOffset=0; break; case 1: initOffset=8192; break; case 2: initOffset=16384; break; case 3: initOffset=24576; break; } //先向上位机发送当前发送的是图像数据的第mark片 do { uWork=LSR; } while ( uWork&0x040 != 0x040 ); THR=mark; //向上位机发送第mark片数据 #pragma MUST_ITERATE(8192,8192); for ( index=0;index<8192;index++ ) { do { uWork=LSR; } while ( uWork&0x040 != 0x040 ); THR=*(pImage+initOffset+index); //这个延时对于上位机很重要，太小就会使上位机接收混乱 wait(4); //wait(128); } return 0x01; }