【数字信号加密解密】基于matlab DES二进制数字信号加密解密【含Matlab源码 3785期】.zip

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%----------------------------- 主函数 -----------------------------%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% function data_decrypt = DES_Decrypt(r_encrypt,key2,r_length) %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % 功能： DES解密 % 输入： r_encrypt 加密数据信号 % key2 解密密钥 % r_length 原始数据信号长度 % 输出： data_decrypt 解密后的数据信号 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%---------------- 变量赋初值 ----------------%%%%%%%%%%%%%%%%%%%%%%%%%%%% global irt endrt ert iprt pt %%%%%%%--- DES加（解）密置换表 ----%%%%%%% irt = ... % 明文初始置换表 [58 50 42 34 26 18 10 2 ... 60 52 44 36 28 20 12 4 ... 62 54 46 38 30 22 14 6 ... 64 56 48 40 32 24 16 8 ... 57 49 41 33 25 17 9 1 ... 59 51 43 35 27 19 11 3 ... 61 53 45 37 29 21 13 5 ... 63 55 47 39 31 23 15 7]; endrt = ... % 明文逆置换表 [40 8 48 16 56 24 64 32 ... 39 7 47 15 55 23 63 31 ... 38 6 46 14 54 22 62 30 ... 37 5 45 13 53 21 61 29 ... 36 4 44 12 52 20 60 28 ... 35 3 43 11 51 19 59 27 ... 34 2 42 10 50 18 58 26 ... 33 1 41 9 49 17 57 25]; ert = ... % 明文扩展置换表 [32 1 2 3 4 5 4 5 ... 6 7 8 9 8 9 10 11 ... 12 13 12 13 14 15 16 17 ... 16 17 18 19 20 21 20 21 ... 22 23 24 25 24 25 26 27 ... 28 29 28 29 30 31 32 1]; iprt = ... % 密钥初始置换表 [57 49 41 33 25 17 9 1 ... 58 50 42 34 26 18 10 2 ... 59 51 43 35 27 19 11 3 ... 60 52 44 36 63 55 47 39 ... 31 23 15 7 62 54 46 38 ... 30 22 14 6 61 53 45 37 ... 29 21 13 5 28 20 12 4]; pt = ... % P置换表 [16 7 20 21 29 12 28 17 ... 1 15 23 26 5 18 31 10 ... 2 8 24 14 32 27 3 9 ... 19 13 30 6 22 11 4 25]; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%----------------- DES解密 -----------------%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%--- 读取需要解密的数据 ---%%%%%%%%% data = r_encrypt; % 提取需要解密的数据 data_length = length(data); % 求取字符长度 adds = 64-mod(data_length,64); % 求取需要补充的字符数 if adds ~= 0 for i = 1:adds data(data_length+i) = 0; % 不足64位的分组数据后面补零 end data_length1 = data_length+adds; % 补零后的位数 end temp = data; data = []; for i = 1:data_length1 data = [data,dec2bin(temp(i))]; % 将双精度二进制数据转换为字符串格式 end %%%%%%%%%%%%---- 读取密钥 -----%%%%%%%%%%%% key = key2; % 提取密钥字符 keylength = length(key); % 求取字符长度 keytemp0 = uint8(key); % 将字符转换为八位二进制整型 keys = [149 57 208 147 21 183 27]; % 密钥不足7位时的补充密钥 %%%%%%%%%%--- 将密钥调整为7位 ---%%%%%%%%%% if keylength < 7 % 延长小于七位的密钥 for i = keylength+1:7 keytemp0(i) = keys(i); end end for i=1:7 % 缩短大于七位的密钥 keyusetemp(i) = keytemp0(i); end keyuse = char(keyusetemp); % 将密钥转换字符型数据 %%%%%%%%%%--- 形成16轮子密钥 ---%%%%%%%%%%% pwb = str2bin(keyuse,7,2); % 密钥转二进制,并加入偶校验位 pwb = rebit(pwb,iprt); % 密钥初始置换 ki = gerkey(pwb); % 计算16轮子密钥 ki = flipud(ki); % 对16轮子密钥进行倒置 %%%%%%%%%%%--- 解密文件数据 ---%%%%%%%%%%%% times = data_length1/64; % 分组解密的组数 for i = 0:times-1 for j = 1:64 tempdata(j) = data(64*i+j); % 提取第i组数据 end decrydata = des(tempdata,ki); % 调用des函数利用密钥ki对tempdata解密 data_decrypt(i*64+1:(i+1)*64) = decrydata; end temp = data_decrypt; data_decrypt = zeros(1,r_length); % 解密后的二进制数据（双精度格式） for i = 1:r_length if temp(i) == '1' data_decrypt(i) = 1; else data_decrypt(i) = 0; end end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%----------------------------- 子函数 -----------------------------%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%-------------- 子函数str2bin --------------%%%%%%%%%%%%%%%%%%%%%%%%%%%% function bin = str2bin(str,k,flag) % 功能：字符串转二进制串,字符串中每个字符对应8位二进制字符 % 输入：str 字符向量 ASCII字符串 % k 正整数 参与每次奇偶校验位运算的bit位数 % flag 正整数 用以说明是否在二进制串中每隔k位加一位奇偶校验位，0表示不加，1表示加奇校验位，2表示加偶校验位 % 输出：bin 字符向量 二进制字符串 % 说明：当length(str)*8 mod k!=0时，对bin二进制串最后length(str)*8 mod k 位补零到k位后再做奇校验 l = length(str); bin = []; temp = []; for x = 1:l temp = [temp,dec2bin(str(x),8)]; % 将字符串转换为二进制串 end if flag ~= 0 % 判断是否需要加奇偶校验位 n = ceil(l*8/k); % 校验位总位数 rb = mod(l*8,k); sb = 0; if rb ~= 0 sb = k-rb; % 算出当二进制串做奇偶校验位时，在串尾补零的个数 for i = 1:sb z(i) = '0'; end temp = [temp z]; end for x = 0:n-1 temp1 = temp(x*k+1:(x+1)*k); lone = length(find(temp1 == '1')); % 求k位二进制串中1的个数 if flag == 1 % 计算奇校验位值 if mod(lone,2) == 0 opb = '1'; else opb = '0'; end else if flag == 2 % 计算偶校验位值 if mod(lone,2) == 0 opb = '0'; else opb = '1'; end end end temp1 = [temp1 opb]; % 添加校验位 bin = [bin temp1]; end else bin = temp; end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%--------------- 子函数rebit ---------------%%%%%%%%%%%%%%%%%%%%%%%%%%%% function so = rebit(si,k) %功能：将si中的位根据置换表k进行置换 %输入：si 一维字符类型向量 要做位置换处理的串 % k 一维字符类型向量 置换表 %输出：so 一维字符类型向量 si置换后的结果 lk=length(k); for i=1:lk so(i)=si(k(i)); end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%--------------- 子函数gerkey ---------------%%%%%%%%%%%%%%%%%%%%%%%%%%%% function ki=gerkey(k) %功能：实现des加密过程中从56位的K密钥产生16个48位Ki子密钥 %输入：k 56位长的行向量 存储56位主密钥K % mt 矩阵 大小2*16 每轮循环左移位数表 % eg. % mt=[1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16;1 1 2 2 2 2 2 2 1 2 2 2 2 2 2 1]; % 移位表第一行为轮数，第二行为第一行对应轮数左移的位数 % rt 一维向量 长度48 置换表 %输出：ki 16*48的矩阵存储16个48位子密钥，ki的第一行代表第一个子密钥，第二行代表第二个子密钥...... mt = ... % 移位表（第一行为轮数，第二行为第一行对应轮数左移的位数） [1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16; 1 1 2 2 2 2 2 2 1 2 2 2 2 2 2 1]; rt = ... % 56位到48位压缩置换表 [14 17 11 24 1 5 3 28 ... 15 6 21 10 23 19 12 4 ... 26 8 16 7 27 20 13 2 ... 41 52 31 37 47 55 30 40 ... 51 45 33 48 44 49 39 56 ... 34 53 46 42 50 36