diff --git a/Crypt.php b/Crypt.php
new file mode 100644
index 0000000..b0b2bf9
--- /dev/null
+++ b/Crypt.php
@@ -0,0 +1,136 @@
+<?php 
+
+namespace killua;
+
+final class Crypt0 {
+    
+    // a string of all alphanumeric characters
+    // used for random string generation
+    public static $chars = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
+	
+    public static function encode_url( string $str ) : string {
+		$i       = -1;
+	    $encoded = '';
+
+	    while( ($i++) < mb_strlen( $str ) - 1 ){
+		    if( $str[$i] == ' ' ){
+			    $encoded .= '+';
+		    }
+		    else if( (ord( $str[$i] ) <= 57 && ord( $str[$i] ) >= 48)  || 
+				     (ord( $str[$i] ) >= 65 && ord( $str[$i] ) <= 90)  || 
+				     (ord( $str[$i] ) >= 97 && ord( $str[$i] ) <= 122) || 
+				     ( $str[$i] == '-' || $str[$i] == '_' || $str[$i] == '.' || $str[$i] == '~' ) ){
+
+			    $encoded .= $str[$i];
+		    }
+		    else{
+			    $encoded .= '%';
+			    //$encoded .= self::$alnum[ ord( $str[$i] ) >> 4 ] . '';
+				//$encoded .= self::$alnum[ ord( $str[$i] ) & 15 ] . '';
+				$encoded   .= self::dec_2_hex( (int) ord( $str[$i] ) );
+		    }
+	    }
+	    return $encoded;
+    }
+
+
+    public static function decode_url( string $str ) : string {
+		$i       = -1;
+	    $decoded = '';
+	}
+	
+
+    public static function signature_generate() : string {
+	    $length 	= strlen( self::$chars );
+	    $signature  = '';
+	    $i			= 0;
+	    $fp         = fopen( '/dev/urandom', 'rb' );
+	    $f          = fread( $fp, strlen( self::$chars ) );
+
+	    while( ( $i++ ) < $length ) {
+		    if( $i % 4 == 0 ){
+			    $signature .= dechex( ord( $f[$i] ) );
+		    } else{
+			    $signature .= self::$chars[ mt_rand( 0, $length - 1 ) ];
+		    }
+	    }
+	    return substr( $signature, 0, strlen( $signature ) - 5 );
+    }
+
+
+	public static function dec_2_hex( int $dec_num ) : string {
+		$hex       = '';
+		$remainder = 0;
+		
+		while( (int) $dec_num != 0 ){
+			$remainder = $dec_num % 16;
+			if( $remainder <= 9 ){
+				$hex .= chr( $remainder + 48 );
+			}
+			else{
+				$hex .= chr( $remainder + ( (48 << 1) - 9 ) );
+			}
+			$dec_num /= 16;
+		}
+		return strrev( $hex );
+	}
+
+
+	public static function hex_2_dec( string $hex_string ) : int {
+		$d          = 0;
+		$num        = 0;
+		$i          = strlen( $hex_string );
+		$hex_string = strrev( $hex_string );
+		
+		while( ($i--) > 0 ){
+			if( ord( $hex_string[$i] ) >= 65 && ord( $hex_string[$i] ) <= 90 ){
+				$d    = ord( $hex_string[$i] ) - ord('A') + 10;
+				$num += (int) ($d * (16 ** $i));
+			}
+			else if( ord( $hex_string[$i] ) >= 97 && ord( $hex_string[$i] ) <= 122 ){
+				$d    = ord( $hex_string[$i] ) - ord('a') + 10;
+				$num += (int) ($d * (16 ** $i));
+			}
+			else{
+				$num += (int) ((int) $hex_string[$i] * (16 ** $i));
+			}
+		}
+		return $num;
+	}
+
+	# ROT13 cipher
+	public static function rot13 ( string $str ) : string {
+		$i      = -1;
+		$newStr = '';
+		while ( ($i++) < mb_strlen( $str ) - 1 ) {
+			if ( (ord($str[$i]) >= ord('A') && ord($str[$i]) <= ord('M') ) 
+			  || (ord($str[$i]) >= ord('a') && ord($str[$i]) <= ord('m') ) ) {
+				$newStr .= chr( ord( $str[$i] ) + 13 );
+			}
+			else if ( (ord($str[$i]) >= ord('N') && ord($str[$i]) <= ord('Z')) 
+				   || (ord($str[$i]) >= ord('n') && ord($str[$i]) <= ord('z')) ) {
+				$newStr .= chr( ord( $str[$i] ) - 13 );
+			}
+			else{
+				$newStr .= $str[$i];
+			}
+		}
+		return $newStr;
+	}
+
+
+    public static function dec_2_bin( int $dec_num ) : string {
+        $i   = -1;
+        $bin = '';
+
+        while( $dec_num ){
+            $bin .= (string) ($dec_num & 1);
+            $dec_num >>= 1;
+        }
+        return strrev( $bin );
+    }
+}
+
+//echo \killua\Crypt0::dec_2_hex( 346777 );
+echo \killua\Crypt0::hex_2_dec( '3a3' );
+?>