自定义加密算法的实现

echo encrypt(1234, 'abc'), PHP_EOL;
echo decrypt( '1TgGSY', 'abc');function encrypt($id, $key) {
  $dict = array('1','2','3','4','5','6','7','8','9',
    'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',
    'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
    '-','=','*'
  );
  $key = current(unpack('L', sha1($key, 1)));
  $id ^= $key;
  $t = str_split(sprintf('%036b', $id), 6);
  foreach($t as &$v) $v = $dict[bindec($v)];
  return join($t);
}function decrypt($s, $key) {
  $dict = array('1','2','3','4','5','6','7','8','9',
    'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',
    'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
    '-','=','*'
  );
  $dict = array_flip($dict);
  foreach(str_split($s) as $c) $r[] = sprintf('%06b', $dict[$c]);
  $id = bindec(join($r));
  $key = current(unpack('L', sha1($key, 1)));
  return $id ^ $key;
}1TgGSY
1234

我自己也实现了加密过程，不过看起来就没那么优雅了，执行效率也低点，贴出来衬托下高手风范 $key_string = 'abc';
function keyToInt($key) {
$key_sha1 = sha1 ( $key );
$first_char = $key_sha1 [0];
if (ord ( $first_char ) > 55) {
return hexdec ( (hexdec ( $first_char ) & 7) . substr ( $key_sha1, 1, 7 ) ) | (- 2147483648);
} else {
return hexdec ( $key_sha1 );
}
}function Encrypt($num){

$dict = array('0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','*','!');
$r1 = $num ^ keyToInt ( $key_string );
$r2 = decbin ( $r1 );
$r3 = array (
bindec ( substr ( $r2, 0, 2 ) ),
bindec ( substr ( $r2, 2, 6 ) ),
bindec ( substr ( $r2, 8, 6 ) ),
bindec ( substr ( $r2, 14, 6 ) ),
bindec ( substr ( $r2, 20, 6 ) ),
bindec ( substr ( $r2, 26, 6 ) )
);
return $dict [$r3 [0]] . $dict [$r3 [1]] . $dict [$r3 [2]] . $dict [$r3 [3]] . $dict [$r3 [4]] . $dict [$r3 [5]];
}算法实现之后，发觉在设计算法时，有个缺陷没考虑到，由于仅仅是id与key异或，加密后的结果存在一定规律性，比如
1234->1TgGSY
1235->1TgGSX有没有什么好的办法打散下结果?

这个够乱的了吧$id = 1234;
$key = 'aaa';
for($i=1; $i<100; $i++) {
  printf("%-10d %s %s\n", $id, $s = encrypt($id++, $key), decrypt( $s, $key));
}function encrypt($id, $key) {
  $dict = array('1','2','3','4','5','6','7','8','9',
    'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',
    'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
    '-','=','*'
  );
  $n = rand(0, 15);
  srand($n);
  $key = current(unpack('L', substr(sha1($key, 1), $n)));
  $id ^= $key;
  $t = str_split(sprintf('%04b%032b', $n, $id), 6);
  foreach($t as $i=>&$v) {
    $v = $dict[bindec($v)];
    if($i == 0) shuffle($dict);
  }
  return join($t);
}function decrypt($s, $key) {
  $dict = array('1','2','3','4','5','6','7','8','9',
    'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',
    'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
    '-','=','*'
  );
  $m = array_search($s{0}, $dict);
  $n = $m >> 2;
  srand($n);
  shuffle($dict);
  $dict = array_flip($dict);
  foreach(str_split($s) as $i=>$c) {
    $r[] = sprintf('%06b', $i==0 ? $m&0x03 : $dict[$c]);
  }
  $id = bindec(join($r));
  $key = current(unpack('L', substr(sha1($key, 1), $n)));
  return $id ^ $key;
}
1234       4rHK4B 1234
1235       oD2LN* 1235
1236       wqkf8u 1236
1237       6k=GVU 1237
1238       bxeCr* 1238
1239       =W-AOi 1239
1240       IiQ3e1 1240
1241       z6uMMA 1241
1242       WLcnd8 1242
1243       Rizj*M 1243
1244       4rHK47 1244
1245       oD2LNT 1245
1246       wqkf8Z 1246
1247       6k=GVJ 1247
1248       bxeCrE 1248
1249       =W-AOP 1249
1250       IiQ3et 1250
1251       z6uMMP 1251
1252       WLcndU 1252
1253       Rizj*p 1253
1254       4rHK4s 1254
1255       oD2LNs 1255
1256       wqkf84 1256
1257       6k=GVn 1257
1258       bxeCrL 1258
1259       =W-AOT 1259
1260       IiQ3ex 1260
1261       z6uMM1 1261
1262       WLcndD 1262
1263       Rizj*s 1263
1264       4rHK4h 1264
1265       oD2LNq 1265
1266       wqkf83 1266
1267       6k=GVg 1267
1268       bxeCr5 1268
1269       =W-AOH 1269
1270       IiQ3eP 1270
1271       z6uMMc 1271
1272       WLcndE 1272
1273       Rizj*6 1273
1274       4rHK4I 1274
1275       oD2LN= 1275
1276       wqkf8U 1276
1277       6k=GVI 1277
1278       bxeCr9 1278
1279       =W-AOl 1279
1280       IiQ3bI 1280
1281       z6uMhG 1281
1282       WLcnaY 1282
1283       Rizj6d 1283
1284       4rHK3Z 1284
1285       oD2L*n 1285
1286       wqkfbP 1286
1287       6k=Gzj 1287
1288       bxeC=o 1288
1289       =W-AEd 1289
1290       IiQ3bY 1290
1291       z6uMh* 1291
1292       WLcnag 1292
1293       Rizj6v 1293
1294       4rHK3F 1294
1295       oD2L*e 1295
1296       wqkfbJ 1296
1297       6k=Gzm 1297
1298       bxeC=N 1298
1299       =W-AEw 1299
1300       IiQ3bs 1300
1301       z6uMhl 1301
1302       WLcna4 1302
1303       Rizj6V 1303
1304       4rHK3u 1304
1305       oD2L*V 1305
1306       wqkfbm 1306
1307       6k=Gz* 1307
1308       bxeC=- 1308
1309       =W-AEa 1309
1310       IiQ3bm 1310
1311       z6uMhe 1311
1312       WLcnaS 1312
1313       Rizj6= 1313
1314       4rHK38 1314
1315       oD2L*l 1315
1316       wqkfbS 1316
1317       6k=Gz6 1317
1318       bxeC=q 1318
1319       =W-AEn 1319
1320       IiQ3bO 1320
1321       z6uMhV 1321
1322       WLcnau 1322
1323       Rizj61 1323
1324       4rHK3K 1324
1325       oD2L*p 1325
1326       wqkfbv 1326
1327       6k=Gzw 1327
1328       bxeC=h 1328
1329       =W-AE- 1329
1330       IiQ3bS 1330
1331       z6uMhj 1331
1332       WLcna9 1332

在你的设计中，第一节只有 2bit 有效位，所以可在其上再附加4bit信息
而0~15的随机数正好是4bit算法中，这个随机数起到2个作用
1、调整 key
2、打乱字典

如果不怎么需要太强的保密性，位运算移位就足够了，省点CPU

调试易

自定义加密算法的实现

解决方案 »