protected function decipher(&$xl, &$xr)
  {
    for($i = 17; $i > 1; $i--)
    {
      $temp = $xl ^ $this->p[$i];
      $xl = ((($this->s[0][($temp>>24) & 255] + $this->s[1][($temp>>16) & 255]) ^ $this->s[2][($temp>>8) & 255]) + $this->s[3][$temp & 255]) ^ $xr;
      $xr = $temp;
    }

    $xr = $xl ^ $this->p[1];
    $xl = $temp ^ $this->p[0];
  }
protected function decipher(&$xl, &$xr)
  {
    for($i = 17; $i > 1; $i--)
    {
      $temp = $xl ^ $this->p[$i];
      $xl = ((($this->s[0][($temp>>24) & 255] + $this->s[1][($temp>>16) & 255]) ^ $this->s[2][($temp>>8) & 255]) + $this->s[3][$temp & 255]) ^ $xr;
      $xr = $temp;
    }

    $xr = $xl ^ $this->p[1];
    $xl = $temp ^ $this->p[0];
  }
protected function decipher ( & $ xl , & $ xr ) { for ( $ i = 17 ; $ i > 1 ; $ i -- ) { $ temp = $ xl ^ $ this -> p [ $ i ] ; $ xl = ( ( ( $ this -> s [ 0 ] [ ( $ temp >> 24 ) & 255 ] + $ this -> s [ 1 ] [ ( $ temp >> 16 ) & 255 ] ) ^ $ this -> s [ 2 ] [ ( $ temp >> 8 ) & 255 ] ) + $ this -> s [ 3 ] [ $ temp & 255 ] ) ^ $ xr ; $ xr = $ temp ; } $ xr = $ xl ^ $ this -> p [ 1 ] ; $ xl = $ temp ^ $ this -> p [ 0 ] ; }
Deciphers a single 64-bit block

@param  integer $xl
@param  integer $xr
@return void
Deciphers a single 64 - bit block