Created
October 10, 2015 19:19
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<?php | |
class PseudoCrypt { | |
/* Key: Next prime greater than 62 ^ n / 1.618033988749894848 */ | |
/* Value: modular multiplicative inverse */ | |
private static $golden_primes = array( | |
'1' => '1', | |
'41' => '59', | |
'2377' => '1677', | |
'147299' => '187507', | |
'9132313' => '5952585', | |
'566201239' => '643566407', | |
'35104476161' => '22071637057', | |
'2176477521929' => '294289236153', | |
'134941606358731' => '88879354792675', | |
'8366379594239857' => '7275288500431249', | |
'518715534842869223' => '280042546585394647' | |
); | |
/* Ascii : 0 9, A Z, a z */ | |
/* $chars = array_merge(range(48,57), range(65,90), range(97,122)) */ | |
private static $chars62 = array( | |
0=>48,1=>49,2=>50,3=>51,4=>52,5=>53,6=>54,7=>55,8=>56,9=>57,10=>65, | |
11=>66,12=>67,13=>68,14=>69,15=>70,16=>71,17=>72,18=>73,19=>74,20=>75, | |
21=>76,22=>77,23=>78,24=>79,25=>80,26=>81,27=>82,28=>83,29=>84,30=>85, | |
31=>86,32=>87,33=>88,34=>89,35=>90,36=>97,37=>98,38=>99,39=>100,40=>101, | |
41=>102,42=>103,43=>104,44=>105,45=>106,46=>107,47=>108,48=>109,49=>110, | |
50=>111,51=>112,52=>113,53=>114,54=>115,55=>116,56=>117,57=>118,58=>119, | |
59=>120,60=>121,61=>122 | |
); | |
public static function base62($int) { | |
$key = ""; | |
while(bccomp($int, 0) > 0) { | |
$mod = bcmod($int, 62); | |
$key .= chr(self::$chars62[$mod]); | |
$int = bcdiv($int, 62); | |
} | |
return strrev($key); | |
} | |
public static function hash($num, $len = 5) { | |
$ceil = bcpow(62, $len); | |
$primes = array_keys(self::$golden_primes); | |
$prime = $primes[$len]; | |
$dec = bcmod(bcmul($num, $prime), $ceil); | |
$hash = self::base62($dec); | |
return str_pad($hash, $len, "0", STR_PAD_LEFT); | |
} | |
public static function unbase62($key) { | |
$int = 0; | |
foreach(str_split(strrev($key)) as $i => $char) { | |
$dec = array_search(ord($char), self::$chars62); | |
$int = bcadd(bcmul($dec, bcpow(62, $i)), $int); | |
} | |
return $int; | |
} | |
public static function unhash($hash) { | |
$len = strlen($hash); | |
$ceil = bcpow(62, $len); | |
$mmiprimes = array_values(self::$golden_primes); | |
$mmi = $mmiprimes[$len]; | |
$num = self::unbase62($hash); | |
$dec = bcmod(bcmul($num, $mmi), $ceil); | |
return $dec; | |
} | |
} | |
echo "<pre>"; | |
foreach(range(1, 10) as $n) { | |
echo $n." - "; | |
$hash = PseudoCrypt::hash($n, 6); | |
echo $hash." - "; | |
echo PseudoCrypt::unhash($hash)."<br/>"; | |
} |
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