DES加密过程和解密过程的区别 为什么des算法的解密过程是加密过程的逆过程
des\u7b97\u6cd5\u52a0\u5bc6\u89e3\u5bc6\u7684\u5b9e\u73b0\u4e00\uff0e\u52a0\u5bc6
DES\u7b97\u6cd5\u5904\u7406\u7684\u6570\u636e\u5bf9\u8c61\u662f\u4e00\u7ec464\u6bd4\u7279\u7684\u660e\u6587\u4e32\u3002\u8bbe\u8be5\u660e\u6587\u4e32\u4e3am=m1m2\u2026m64 (mi=0\u62161)\u3002\u660e\u6587\u4e32\u7ecf\u8fc764\u6bd4\u7279\u7684\u5bc6\u94a5K\u6765\u52a0\u5bc6\uff0c\u6700\u540e\u751f\u6210\u957f\u5ea6\u4e3a64\u6bd4\u7279\u7684\u5bc6\u6587E\u3002\u5176\u52a0\u5bc6\u8fc7\u7a0b\u56fe\u793a\u5982\u4e0b\uff1a
DES\u7b97\u6cd5\u52a0\u5bc6\u8fc7\u7a0b
\u5bf9DES\u7b97\u6cd5\u52a0\u5bc6\u8fc7\u7a0b\u56fe\u793a\u7684\u8bf4\u660e\u5982\u4e0b\uff1a\u5f85\u52a0\u5bc6\u768464\u6bd4\u7279\u660e\u6587\u4e32m\uff0c\u7ecf\u8fc7IP\u7f6e\u6362\u540e\uff0c\u5f97\u5230\u7684\u6bd4\u7279\u4e32\u7684\u4e0b\u6807\u5217\u8868\u5982\u4e0b\uff1a
IP 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
\u8be5\u6bd4\u7279\u4e32\u88ab\u5206\u4e3a32\u4f4d\u7684L0\u548c32\u4f4d\u7684R0\u4e24\u90e8\u5206\u3002R0\u5b50\u5bc6\u94a5K1(\u5b50\u5bc6\u94a5\u7684\u751f\u6210\u5c06\u5728\u540e\u9762\u8bb2)\u7ecf\u8fc7\u53d8\u6362f(R0,K1)\uff08f\u53d8\u6362\u5c06\u5728\u4e0b\u9762\u8bb2\uff09\u8f93\u51fa32\u4f4d\u7684\u6bd4\u7279\u4e32f1,f1\u4e0eL0\u505a\u4e0d\u8fdb\u4f4d\u7684\u4e8c\u8fdb\u5236\u52a0\u6cd5\u8fd0\u7b97\u3002\u8fd0\u7b97\u89c4\u5219\u4e3a\uff1a
f1\u4e0eL0\u505a\u4e0d\u8fdb\u4f4d\u7684\u4e8c\u8fdb\u5236\u52a0\u6cd5\u8fd0\u7b97\u540e\u7684\u7ed3\u679c\u8d4b\u7ed9R1\uff0cR0\u5219\u539f\u5c01\u4e0d\u52a8\u7684\u8d4b\u7ed9L1\u3002L1\u4e0eR0\u53c8\u505a\u4e0e\u4ee5\u4e0a\u5b8c\u5168\u76f8\u540c\u7684\u8fd0\u7b97\uff0c\u751f\u6210L2\uff0cR2\u2026\u2026 \u4e00\u5171\u7ecf\u8fc716\u6b21\u8fd0\u7b97\u3002\u6700\u540e\u751f\u6210R16\u548cL16\u3002\u5176\u4e2dR16\u4e3aL15\u4e0ef(R15,K16)\u505a\u4e0d\u8fdb\u4f4d\u4e8c\u8fdb\u5236\u52a0\u6cd5\u8fd0\u7b97\u7684\u7ed3\u679c\uff0cL16\u662fR15\u7684\u76f4\u63a5\u8d4b\u503c\u3002
R16\u4e0eL16\u5408\u5e76\u621064\u4f4d\u7684\u6bd4\u7279\u4e32\u3002\u503c\u5f97\u6ce8\u610f\u7684\u662fR16\u4e00\u5b9a\u8981\u6392\u5728L16\u524d\u9762\u3002R16\u4e0eL16\u5408\u5e76\u540e\u6210\u7684\u6bd4\u7279\u4e32\uff0c\u7ecf\u8fc7\u7f6e\u6362IP-1\u540e\u6240\u5f97\u6bd4\u7279\u4e32\u7684\u4e0b\u6807\u5217\u8868\u5982\u4e0b\uff1a
IP-1 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
\u7ecf\u8fc7\u7f6e\u6362IP-1\u540e\u751f\u6210\u7684\u6bd4\u7279\u4e32\u5c31\u662f\u5bc6\u6587e.\u3002
\u4e0b\u9762\u518d\u8bb2\u4e00\u4e0b\u53d8\u6362f(Ri-1,Ki)\u3002
\u5b83\u7684\u529f\u80fd\u662f\u5c0632\u6bd4\u7279\u7684\u8f93\u5165\u518d\u8f6c\u5316\u4e3a32\u6bd4\u7279\u7684\u8f93\u51fa\u3002\u5176\u8fc7\u7a0b\u5982\u56fe\u6240\u793a\uff1a
\u5bf9f\u53d8\u6362\u8bf4\u660e\u5982\u4e0b\uff1a\u8f93\u5165Ri-1(32\u6bd4\u7279)\u7ecf\u8fc7\u53d8\u6362E\u540e\uff0c\u81a8\u80c0\u4e3a48\u6bd4\u7279\u3002\u81a8\u80c0\u540e\u7684\u6bd4\u7279\u4e32\u7684\u4e0b\u6807\u5217\u8868\u5982\u4e0b\uff1a
E: 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 31
\u81a8\u80c0\u540e\u7684\u6bd4\u7279\u4e32\u5206\u4e3a8\u7ec4\uff0c\u6bcf\u7ec46\u6bd4\u7279\u3002\u5404\u7ec4\u7ecf\u8fc7\u5404\u81ea\u7684S\u76d2\u540e\uff0c\u53c8\u53d8\u4e3a4\u6bd4\u7279(\u5177\u4f53\u8fc7\u7a0b\u89c1\u540e)\uff0c\u5408\u5e76\u540e\u53c8\u6210\u4e3a32\u6bd4\u7279\u3002\u8be532\u6bd4\u7279\u7ecf\u8fc7P\u53d8\u6362\u540e\uff0c\u5176\u4e0b\u6807\u5217\u8868\u5982\u4e0b\uff1a
P: 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
\u7ecf\u8fc7P\u53d8\u6362\u540e\u8f93\u51fa\u7684\u6bd4\u7279\u4e32\u624d\u662f32\u6bd4\u7279\u7684f (Ri-1,Ki)\u3002
\u4e0b\u9762\u518d\u8bb2\u4e00\u4e0bS\u76d2\u7684\u53d8\u6362\u8fc7\u7a0b\u3002\u4efb\u53d6\u4e00S\u76d2\u3002\u89c1\u56fe\uff1a
\u5728\u5176\u8f93\u5165b1,b2,b3,b4,b5,b6\u4e2d\uff0c\u8ba1\u7b97\u51fax=b1*2+b6, y=b5+b4*2+b3*4+b2*8\uff0c\u518d\u4eceSi\u8868\u4e2d\u67e5\u51fax \u884c\uff0cy \u5217\u7684\u503cSxy\u3002\u5c06Sxy\u5316\u4e3a\u4e8c\u8fdb\u5236\uff0c\u5373\u5f97Si\u76d2\u7684\u8f93\u51fa\u3002\uff08S\u8868\u5982\u56fe\u6240\u793a\uff09
\u81f3\u6b64\uff0cDES\u7b97\u6cd5\u52a0\u5bc6\u539f\u7406\u8bb2\u5b8c\u4e86\u3002\u5728VC++6.0\u4e0b\u7684\u7a0b\u5e8f\u6e90\u4ee3\u7801\u4e3a\uff1a
for(i=1;i<=64;i++)
m1[i]=m[ip[i-1]];//64\u4f4d\u660e\u6587\u4e32\u8f93\u5165\uff0c\u7ecf\u8fc7IP\u7f6e\u6362\u3002
\u4e0b\u9762\u8fdb\u884c\u8fed\u4ee3\u3002\u7531\u4e8e\u5404\u6b21\u8fed\u4ee3\u7684\u65b9\u6cd5\u76f8\u540c\u53ea\u662f\u8f93\u5165\u8f93\u51fa\u4e0d\u540c\uff0c\u56e0\u6b64\u53ea\u7ed9\u51fa\u5176\u4e2d\u4e00\u6b21\u3002\u4ee5\u7b2c\u516b\u6b21\u4e3a\u4f8b\uff1a//\u8fdb\u884c\u7b2c\u516b\u6b21\u8fed\u4ee3\u3002\u9996\u5148\u8fdb\u884cS\u76d2\u7684\u8fd0\u7b97\uff0c\u8f93\u516532\u4f4d\u6bd4\u7279\u4e32\u3002
for(i=1;i<=48;i++)//\u7ecf\u8fc7E\u53d8\u6362\u6269\u5145\uff0c\u753132\u4f4d\u53d8\u4e3a48\u4f4d
RE1[i]=R7[E[i-1]];
for(i=1;i<=48;i++)//\u4e0eK8\u6309\u4f4d\u4f5c\u4e0d\u8fdb\u4f4d\u52a0\u6cd5\u8fd0\u7b97
RE1[i]=RE1[i]+K8[i];
for(i=1;i<=48;i++)
{
if(RE1[i]==2)
RE1[i]=0;
}
for(i=1;i<7;i++)//48\u4f4d\u5206\u62108\u7ec4
{
s11[i]=RE1[i];
s21[i]=RE1[i+6];
s31[i]=RE1[i+12];
s41[i]=RE1[i+18];
s51[i]=RE1[i+24];
s61[i]=RE1[i+30];
s71[i]=RE1[i+36];
s81[i]=RE1[i+42];
}//\u4e0b\u9762\u7ecf\u8fc7S\u76d2\uff0c\u5f97\u52308\u4e2a\u6570\u3002S1,s2,s3,s4,s5,s6,s7,s8\u5206\u522b\u4e3aS\u8868
s[1]=s1[s11[6]+s11[1]*2][s11[5]+s11[4]*2+s11[3]*4+s11[2]*8];
s[2]=s2[s21[6]+s21[1]*2][s21[5]+s21[4]*2+s21[3]*4+s21[2]*8];
s[3]=s3[s31[6]+s31[1]*2][s31[5]+s31[4]*2+s31[3]*4+s31[2]*8];
s[4]=s4[s41[6]+s41[1]*2][s41[5]+s41[4]*2+s41[3]*4+s41[2]*8];
s[5]=s5[s51[6]+s51[1]*2][s51[5]+s51[4]*2+s51[3]*4+s51[2]*8];
s[6]=s6[s61[6]+s61[1]*2][s61[5]+s61[4]*2+s61[3]*4+s61[2]*8];
s[7]=s7[s71[6]+s71[1]*2][s71[5]+s71[4]*2+s71[3]*4+s71[2]*8];
s[8]=s8[s81[6]+s81[1]*2][s81[5]+s81[4]*2+s81[3]*4+s81[2]*8];
for(i=0;i<8;i++)//8\u4e2a\u6570\u53d8\u6362\u8f93\u51fa\u4e8c\u8fdb\u5236
{
for(j=1;j<5;j++)
{
temp[j]=s[i+1]%2;
s[i+1]=s[i+1]/2;
}
for(j=1;j<5;j++)
f[4*i+j]=temp[5-j];
}
for(i=1;i<33;i++)//\u7ecf\u8fc7P\u53d8\u6362
frk[i]=f[P[i-1]];//S\u76d2\u8fd0\u7b97\u5b8c\u6210
for(i=1;i<33;i++)//\u5de6\u53f3\u4ea4\u6362
L8[i]=R7[i];
for(i=1;i<33;i++)//R8\u4e3aL7\u4e0ef(R,K)\u8fdb\u884c\u4e0d\u8fdb\u4f4d\u4e8c\u8fdb\u5236\u52a0\u6cd5\u8fd0\u7b97\u7ed3\u679c
{
R8[i]=L7[i]+frk[i];
if(R8[i]==2)
R8[i]=0;
}
[ \u539f\u521b\u6587\u6863 \u672c\u6587\u9002\u5408\u4e2d\u7ea7\u8bfb\u8005 \u5df2\u9605\u8bfb21783\u6b21 ] \u6587\u6863 \u4ee3\u7801 \u5de5\u5177
DES\u7b97\u6cd5\u53ca\u5176\u5728VC++6.0\u4e0b\u7684\u5b9e\u73b0(\u4e0b)
\u4f5c\u8005\uff1a\u822a\u5929\u533b\u5b66\u5de5\u7a0b\u7814\u7a76\u6240\u56db\u5ba4 \u6731\u5f66\u519b
\u5728\u300aDES\u7b97\u6cd5\u53ca\u5176\u5728VC++6.0\u4e0b\u7684\u5b9e\u73b0(\u4e0a)\u300b\u4e2d\u4e3b\u8981\u4ecb\u7ecd\u4e86DES\u7b97\u6cd5\u7684\u57fa\u672c\u539f\u7406\uff0c\u4e0b\u9762\u8ba9\u6211\u4eec\u7ee7\u7eed\uff1a
\u4e8c\uff0e\u5b50\u5bc6\u94a5\u7684\u751f\u6210
64\u6bd4\u7279\u7684\u5bc6\u94a5\u751f\u621016\u4e2a48\u6bd4\u7279\u7684\u5b50\u5bc6\u94a5\u3002\u5176\u751f\u6210\u8fc7\u7a0b\u89c1\u56fe\uff1a
\u5b50\u5bc6\u94a5\u751f\u6210\u8fc7\u7a0b\u5177\u4f53\u89e3\u91ca\u5982\u4e0b\uff1a
64\u6bd4\u7279\u7684\u5bc6\u94a5K\uff0c\u7ecf\u8fc7PC-1\u540e\uff0c\u751f\u621056\u6bd4\u7279\u7684\u4e32\u3002\u5176\u4e0b\u6807\u5982\u8868\u6240\u793a\uff1a
PC-1 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
\u8be5\u6bd4\u7279\u4e32\u5206\u4e3a\u957f\u5ea6\u76f8\u7b49\u7684\u6bd4\u7279\u4e32C0\u548cD0\u3002\u7136\u540eC0\u548cD0\u5206\u522b\u5faa\u73af\u5de6\u79fb1\u4f4d\uff0c\u5f97\u5230C1\u548cD1\u3002C1\u548cD1\u5408\u5e76\u8d77\u6765\u751f\u6210C1D1\u3002C1D1\u7ecf\u8fc7PC-2\u53d8\u6362\u540e\u5373\u751f\u621048\u6bd4\u7279\u7684K1\u3002K1\u7684\u4e0b\u6807\u5217\u8868\u4e3a\uff1a
PC-2 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 29 32
C1\u3001D1\u5206\u522b\u5faa\u73af\u5de6\u79fbLS2\u4f4d\uff0c\u518d\u5408\u5e76\uff0c\u7ecf\u8fc7PC-2\uff0c\u751f\u6210\u5b50\u5bc6\u94a5K2\u2026\u2026\u4f9d\u6b21\u7c7b\u63a8\u76f4\u81f3\u751f\u6210\u5b50\u5bc6\u94a5K16\u3002
\u6ce8\u610f\uff1aLsi (I =1,2,\u2026.16)\u7684\u6570\u503c\u662f\u4e0d\u540c\u7684\u3002\u5177\u4f53\u89c1\u4e0b\u8868\uff1a
\u8fed\u4ee3\u987a\u5e8f 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
\u5de6\u79fb\u4f4d\u6570 1 1 2 2 2 2 2 2 1 2 2 2 2 2 2 1
\u751f\u6210\u5b50\u5bc6\u94a5\u7684VC\u7a0b\u5e8f\u6e90\u4ee3\u7801\u5982\u4e0b\uff1a
for(i=1;i<57;i++)//\u8f93\u516564\u4f4dK\uff0c\u7ecf\u8fc7PC-1\u53d8\u4e3a56\u4f4d k0[i]=k[PC_1[i-1]];
56\u4f4d\u7684K0\uff0c\u5747\u5206\u4e3a28\u4f4d\u7684C0\uff0cD0\u3002C0\uff0cD0\u751f\u6210K1\u548cC1\uff0cD1\u3002\u4ee5\u4e0b\u51e0\u6b21\u8fed\u4ee3\u65b9\u6cd5\u76f8\u540c\uff0c\u4ec5\u4ee5\u751f\u6210K8\u4e3a\u4f8b\u3002 for(i=1;i<27;i++)//\u5faa\u73af\u5de6\u79fb\u4e24\u4f4d
{
C8[i]=C7[i+2];
D8[i]=D7[i+2];
}
C8[27]=C7[1];
D8[27]=D7[1];
C8[28]=C7[2];
D8[28]=D7[2];
for(i=1;i<=28;i++)
{
C[i]=C8[i];
C[i+28]=D8[i];
}
for(i=1;i<=48;i++)
K8[i]=C[PC_2[i-1]];//\u751f\u6210\u5b50\u5bc6\u94a5k8
\u6ce8\u610f\uff1a\u751f\u6210\u7684\u5b50\u5bc6\u94a5\u4e0d\u540c\uff0c\u6240\u9700\u5faa\u73af\u5de6\u79fb\u7684\u4f4d\u6570\u4e5f\u4e0d\u540c\u3002\u6e90\u7a0b\u5e8f\u4e2d\u4ee5\u751f\u6210\u5b50\u5bc6\u94a5 K8\u4e3a\u4f8b\uff0c\u6240\u4ee5\u5faa\u73af\u5de6\u79fb\u4e86\u4e24\u4f4d\u3002\u4f46\u5728\u7f16\u7a0b\u4e2d\uff0c\u751f\u6210\u4e0d\u540c\u7684\u5b50\u5bc6\u94a5\u5e94\u4ee5Lsi\u8868\u4e3a\u51c6\u3002
\u4e09\uff0e\u89e3\u5bc6
DES\u7684\u89e3\u5bc6\u8fc7\u7a0b\u548cDES\u7684\u52a0\u5bc6\u8fc7\u7a0b\u5b8c\u5168\u7c7b\u4f3c\uff0c\u53ea\u4e0d\u8fc7\u5c0616\u5708\u7684\u5b50\u5bc6\u94a5\u5e8f\u5217K1\uff0cK2\u2026\u2026K16\u7684\u987a\u5e8f\u5012\u8fc7\u6765\u3002\u5373\u7b2c\u4e00\u5708\u7528\u7b2c16\u4e2a\u5b50\u5bc6\u94a5K16\uff0c\u7b2c\u4e8c\u5708\u7528K15\uff0c\u5176\u4f59\u7c7b\u63a8\u3002
\u7b2c\u4e00\u5708\uff1a
\u52a0\u5bc6\u540e\u7684\u7ed3\u679c
L=R15, R=L15\u2295f(R15,K16)\u2295f(R15,K16)=L15
\u540c\u7406R15=L14\u2295f(R14,K15), L15=R14\u3002
\u540c\u7406\u7c7b\u63a8\uff1a
\u5f97 L=R0, R=L0\u3002
\u5176\u7a0b\u5e8f\u6e90\u4ee3\u7801\u4e0e\u52a0\u5bc6\u76f8\u540c\u3002\u5728\u6b64\u5c31\u4e0d\u91cd\u5199\u3002
\u56db\uff0e\u793a\u4f8b
\u4f8b\u5982\uff1a\u5df2\u77e5\u660e\u6587m=learning, \u5bc6\u94a5 k=computer\u3002
\u660e\u6587m\u7684ASCII\u4e8c\u8fdb\u5236\u8868\u793a\uff1a
m= 01101100 01100101 01100001 01110010
01101110 01101001 01101110 01100111
\u5bc6\u94a5k\u7684ASCII\u4e8c\u8fdb\u5236\u8868\u793a\uff1a
k=01100011 01101111 01101101 01110000
01110101 01110100 01100101 01110010
\u660e\u6587m\u7ecf\u8fc7IP\u7f6e\u6362\u540e\uff0c\u5f97\uff1a
11111111 00001000 11010011 10100110 00000000 11111111 01110001 11011000
\u7b49\u5206\u4e3a\u5de6\u53f3\u4e24\u6bb5\uff1a
L0=11111111 00001000 11010011 10100110 R0=00000000 11111111 01110001 11011000
\u7ecf\u8fc716\u6b21\u8fed\u4ee3\u540e\uff0c\u6240\u5f97\u7ed3\u679c\u4e3a\uff1a
L1=00000000 11111111 01110001 11011000 R1=00110101 00110001 00111011 10100101
L2=00110101 00110001 00111011 10100101 R2=00010111 11100010 10111010 10000111
L3=00010111 11100010 10111010 10000111 R3=00111110 10110001 00001011 10000100
L4=00111110101100010000101110000100 R4=11110111110101111111101000111110
L5=11110111110101111111101000111110 R5=10010110011001110100111111100101
L6=10010110011001110100111111100101 R6=11001011001010000101110110100111
L7=11001011001010000101110110100111 R7=01100011110011101000111011011001
L8=01100011110011101000111011011001 R8=01001011110100001111001000000100
L9=01001011110100001111001000000100 R9=00011101001101111010111011100001
L10=00011101001101111010111011100001 R10=11101110111110111111010100000101
L11=11101110111110111111010100000101 R11=01101101111011011110010111111000
L12=01101101111011011110010111111000 R12=11111101110011100111000110110111
L13=11111101110011100111000110110111 R13=11100111111001011010101000000100
L14=11100111111001011010101000000100 R14=00011110010010011011100001100001
L15=00011110010010011011100001100001 R15=01010000111001001101110110100011
L16=01010000111001001101110110100011 R16=01111101101010000100110001100001
\u5176\u4e2d\uff0cf\u51fd\u6570\u7684\u7ed3\u679c\u4e3a\uff1a
f1=11001010001110011110100000000011 f2=00010111000111011100101101011111
f3=00001011100000000011000000100001 f4=11100000001101010100000010111001
f5=10101000110101100100010001100001 f6=00111100111111111010011110011001
f7=11110101101010011100000100111100 f8=10000000111110001010111110100011
f9=01111110111110010010000000111000 f10=10100101001010110000011100000001
f11=01110000110110100100101100011001 f12=00010011001101011000010010110010
f13=10001010000010000100111111111100 f14=11100011100001111100100111010110
f15=10110111000000010111011110100111 f16=01100011111000011111010000000000
16\u4e2a\u5b50\u5bc6\u94a5\u4e3a\uff1a
K1=11110000101111101110111011010000 K2=11100000101111101111011010010101
K3=11110100111111100111011000101000 K4=11100110111101110111001000011010
K5=11101110110101110111011100100110 K6=11101111110100110101101110001011
K7=00101111110100111111101111100110 K8=10111111010110011101101101010000
K9=00011111010110111101101101000100 K10=00111111011110011101110100001001
K11=00011111011011011100110101101000 K12=01011011011011011011110100001010
K13=11011101101011011010110110001111 K14=11010011101011101010111110000000
K15=11111001101111101010011011010011 K16=11110001101111100010111000000001
S\u76d2\u4e2d\uff0c16\u6b21\u8fd0\u7b97\u65f6\uff0c\u6bcf\u6b21\u76848 \u4e2a\u7ed3\u679c\u4e3a\uff1a
\u7b2c\u4e00\u6b21\uff1a5\uff0c11\uff0c4\uff0c1\uff0c0\uff0c3\uff0c13\uff0c9\uff1b
\u7b2c\u4e8c\u6b21\uff1a7\uff0c13\uff0c15\uff0c8\uff0c12\uff0c12\uff0c13\uff0c1\uff1b
\u7b2c\u4e09\u6b21\uff1a8\uff0c0\uff0c0\uff0c4\uff0c8\uff0c1\uff0c9\uff0c12\uff1b
\u7b2c\u56db\u6b21\uff1a0\uff0c7\uff0c4\uff0c1\uff0c7\uff0c6\uff0c12\uff0c4\uff1b
\u7b2c\u4e94\u6b21\uff1a8\uff0c1\uff0c0\uff0c11\uff0c5\uff0c0\uff0c14\uff0c14\uff1b
\u7b2c\u516d\u6b21\uff1a14\uff0c12\uff0c13\uff0c2\uff0c7\uff0c15\uff0c14\uff0c10\uff1b
\u7b2c\u4e03\u6b21\uff1a12\uff0c15\uff0c15\uff0c1\uff0c9\uff0c14\uff0c0\uff0c4\uff1b
\u7b2c\u516b\u6b21\uff1a15\uff0c8\uff0c8\uff0c3\uff0c2\uff0c3\uff0c14\uff0c5\uff1b
\u7b2c\u4e5d\u6b21\uff1a8\uff0c14\uff0c5\uff0c2\uff0c1\uff0c15\uff0c5\uff0c12\uff1b
\u7b2c\u5341\u6b21\uff1a2\uff0c8\uff0c13\uff0c1\uff0c9\uff0c2\uff0c10\uff0c2\uff1b
\u7b2c\u5341\u4e00\u6b21\uff1a10\uff0c15\uff0c8\uff0c2\uff0c1\uff0c12\uff0c12\uff0c3\uff1b
\u7b2c\u5341\u4e8c\u6b21\uff1a5\uff0c4\uff0c4\uff0c0\uff0c14\uff0c10\uff0c7\uff0c4\uff1b
\u7b2c\u5341\u4e09\u6b21\uff1a2\uff0c13\uff0c10\uff0c9\uff0c2\uff0c4\uff0c3\uff0c13\uff1b
\u7b2c\u5341\u56db\u6b21\uff1a13\uff0c7\uff0c14\uff0c9\uff0c15\uff0c0\uff0c1\uff0c3\uff1b
\u7b2c\u5341\u4e94\u6b21\uff1a3\uff0c1\uff0c15\uff0c5\uff0c11\uff0c9\uff0c11\uff0c4\uff1b
\u7b2c\u5341\u516d\u6b21\uff1a12\uff0c3\uff0c4\uff0c6\uff0c9\uff0c3\uff0c3\uff0c0\uff1b
\u5b50\u5bc6\u94a5\u751f\u6210\u8fc7\u7a0b\u4e2d\uff0c\u751f\u6210\u7684\u6570\u503c\u4e3a\uff1a
C0=0000000011111111111111111011 D0=1000001101110110000001101000
C1=0000000111111111111111110110 D1=0000011011101100000011010001
C2=0000001111111111111111101100 D2=0000110111011000000110100010
C3=0000111111111111111110110000 D3=0011011101100000011010001000
C4=0011111111111111111011000000 D4=1101110110000001101000100000
C5=1111111111111111101100000000 D5=0111011000000110100010000011
C6=1111111111111110110000000011 D6=1101100000011010001000001101
C7=1111111111111011000000001111 D7=0110000001101000100000110111
C8=1111111111101100000000111111 D8=1000000110100010000011011101
C9=1111111111011000000001111111 D9=0000001101000100000110111011
C10=1111111101100000000111111111 D10=0000110100010000011011101100
C11=1111110110000000011111111111 D11=0011010001000001101110110000
C12=1111011000000001111111111111 D12=1101000100000110111011000000
C13=1101100000000111111111111111 D13=0100010000011011101100000011
C14=0110000000011111111111111111 D14=0001000001101110110000001101
C15=1000000001111111111111111101 D15=0100000110111011000000110100
C16=0000000011111111111111111011 D16=1000001101110110000001101000
\u6211\u4e5f\u662f\u5416\uff0c\u53d1\u5230\u7a0b\u5e8f\u677f\u5757\u5427\u2026\u2026
数据加密标准DES（Data Encryption Standard）算法是一个分组加密算法，也是一个对称算法，加密和解密使用同一个算法，利用传统的换位、异或、置换等加密方法。DES是IBM在上个世纪70年代开发的简密钥对称加解密算法。加密过程和解密过程的区别：“方向和过程刚好相反”。也就是说“解密过程是加密过程的反过程”，DES算法解密过程是加密过程的“逆”运算。
以Triple DES为例说明
加密过程：
1、以K1加密
2、以K2解密
3、以K3加密
解密过程（密钥顺序及应用方向与加密过程相反）：
1、以K3解密
2、以K2加密
3、以K1解密
说明：K1、K2、K3是密钥。
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绛旓細椤惧悕鎬濅箟锛3DES鍔犲瘑灏辨槸浣跨敤DES绠楁硶鍔犲瘑瑙ｅ瘑3娆★紝鐢变簬DES鍔犲瘑缂轰箯瀹夊叏鎬э紝3DES鍔犲瘑3娆″悗瀹夊叏鎬уぇ澶ф彁楂橈紝浣嗘崯澶变簡涓瀹氱殑閫熷害鎬ц兘锛屾墍浠ユ參鎱㈣鏇翠紭寮傜殑AES鍔犲瘑绠楁硶鎵鍙栦唬锛3DES绠楁硶鍙互璇存槸DES鍔犲瘑鍜孉ES鍔犲瘑涓棿鐨勮繃搴﹀搧銆侫ES鍔瑙ｅ瘑杩囩▼鍜DES鍔犺В瀵嗚繃绋嬬被浼硷紝AES鏍囧噯鏀寔鍙彉鍒嗙粍闀垮害锛屽垎缁勯暱搴﹀彲璁惧畾涓32 ...
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绛旓細涓嶈繃闇瑕佹敞鎰忕殑鏄紝16娆″惊鐜乏绉诲搴旂殑宸︾Щ浣嶆暟瑕佷緷鎹笅杩拌鍒欒繘琛岋細寰幆宸︾Щ浣嶆暟 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1 浠ヤ笂浠嬬粛浜DES绠楁硶鐨鍔犲瘑杩囩▼銆侱ES绠楁硶鐨瑙ｅ瘑杩囩▼鏄竴鏍风殑锛鍖哄埆浠呬粎鍦ㄤ簬绗竴娆¤凯浠ｆ椂鐢ㄥ瓙瀵嗛挜K15锛岀浜屾K14銆...锛屾渶鍚庝竴娆＄敤K0锛岀畻娉曟湰韬苟娌℃湁浠讳綍鍙樺寲銆
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绛旓細DES鏄浜屽厓鏁板瓧鍒嗙粍鍔犲瘑鐨鍒嗙粍瀵嗙爜绠楁硶锛屽垎缁勯暱搴︿负64姣旂壒銆傛瘡64浣嶆槑鏂囧姞瀵嗘垚64浣嶅瘑鏂囷紝娌℃湁鏁版嵁鍘嬬缉鍜屾墿灞曪紝瀵嗛挜闀垮害涓56姣旂壒锛岃嫢杈撳叆64姣旂壒锛屽垯绗8,16,24,32,40,48,56,64涓哄鍋舵楠屼綅锛屾墍浠ワ紝瀹為檯瀵嗛挜鍙湁56浣嶃侱ES绠楁硶瀹屽叏鍏紑锛屽叾淇濆瘑鎬у畬鍏ㄤ緷璧栧瘑閽ャ
