Re: Trying to create an encryption method
| From: | Jochem Maas | Date: | Sun, 05 Nov 2006 12:46:18 +0000 |
| Subject: | Re: Trying to create an encryption method | ||
| References: | 1 2 3 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-244230@lists.php.net to get a copy of this message | ||
$secret = "HalloWorld";
$encoded = "";
$a = $b = range("a","z");
shuffle($b);
$c = array_combine($a, $b);
foreach (str_split(strtolower($secret)) as $v)
$encoded .= isset($c[ $v ]) ? $c[ $v ] : $v;
var_dump($c, $secret, $encoded);
Paul Novitski wrote:
> At 11/4/2006 08:15 PM, John Meyer wrote:
>> I'm trying to create this encryption method for puzzles (nothing super
>> secret, just those cryptograms), but this seems to time out, can anybody
>> point out what I'm doing wrong here:
>>
>> for ($i=1;$i<=26;$i++) {
>> $normalAlphabet[$i] = chr($i);
>> }
>> //now, to shuffle
>>
>> for ($j=1;$j<=26;$j++) {
>> do {
>> $k = rand(1,26);
>> } while ($k == $j || (strlen(trim($normalAlphabet[$k]))
>> === 0));
>> $arEncryptedAlphabet[$j] = $normalAlphabet[$k];
>> $normalAlphabet[$k] = "";
>> }
>> $arNormalString = str_split($normalzedString);
>> $encryptedString = "";
>> for ($i=0;$i<count($arNormalString);$i++) {
>> if (ord($arNormalString[$i])>=65 &&
>> ord($arNormalString[$i])<=90) {
>> $encryptedString = $encryptedString .
>> $arEncryptedAlphabet[ord($arNormalString[$i]) - 64];
>> } else {
>> $encryptedString = $encryptedString .
>> $arNormalString[$i];
>> }
>> }
>> return $encryptedString;
>> }
>
> At 11/4/2006 08:43 PM, Stut wrote:
>> Both the inner loop and the outer loop are using $i, meaning the outer
>> loop will never end since it gets reset in the inner loop.
>
>
> No, there is no loop nesting. The OP's indenting is misleading. Here's
> a reformatted version:
> ____________________________
>
> for ($i=1;$i<=26;$i++)
> {
> $normalAlphabet[$i] = chr($i);
> }
>
> //now, to shuffle
> for ($j=1;$j<=26;$j++)
> {
> do
> {
> $k = rand(1,26);
> }
> while ($k == $j || (strlen(trim($normalAlphabet[$k])) === 0));
>
> $arEncryptedAlphabet[$j] = $normalAlphabet[$k];
> $normalAlphabet[$k] = "";
> }
>
> $arNormalString = str_split($normalzedString);
> $encryptedString = "";
>
> for ($i=0;$i<count($arNormalString);$i++)
> {
> if (ord($arNormalString[$i])>=65 &&
> ord($arNormalString[$i])<=90)
> {
> $encryptedString = $encryptedString .
> $arEncryptedAlphabet[ord($arNormalString[$i]) - 64];
> }
> else
> {
> $encryptedString = $encryptedString .
> $arNormalString[$i];
> }
> }
> return $encryptedString;
>
> }
> ____________________________
>
> The script spends eternity executing the do...while loop. John, display
> your values at each loop while your code is running to see where your
> problem lies.
>
> By the way, are you aware that chr(1) isn't 'A'? It's hex(01).
> 'A' =
> hex(40) = dec(64). Your array $normalAlphabet is not going to contain
> the alphabet the way it's written now.
>
> Regards,
> Paul
>