Experimental check for hash cycles

gistfile1.php

<?php

/**
 * Experimental check for hash cycles
 * Should take about 16 hours, 20 minutes to compute hashes and few more minutes to compare them
 * @author Mikulas Dite
 * @copyright Mikulas Dite 2010
 * @version MD5
 */

const STRINGS = 10e4;
const CYCLES = 10e5;

static $strings = array();
static $result = array();

$timer = time();

for ($i = 0; $i <= STRINGS; $i++) {
	echo "\r", $i, '/', STRINGS;
	if ($i % 20 === 0) {
		$time = (time() - $timer) / ($i + 1);
		$left = STRINGS - $i;
		$total_seconds = (int) ($time * $left);
		
		$hours = (int) ($total_seconds / 3600);
		$minutes = (int) ($total_seconds % 3600 / 60);
		$seconds = $total_seconds - $hours * 3600 - $minutes * 60;
		echo "\t Time left: ";
		if ($hours > 0) {
			echo "$hours hours, ";
		}
		if ($minutes > 0) {
			echo "$minutes minutes, ";
		}
		echo "$seconds seconds";
	}
	$result[$i] = $strings[$i] = generateString();
	
	for ($k = 0; $k <= CYCLES; $k++) {
		$result[$i] = md5($result[$i]);
	}
}

for ($i = 0; $i < count($result); $i++) {
	for ($k = $i; $k < count($result); $k++) {
		if ($result[$i] === $result[$k]
		&& $strings[$i] !== $strings[$k]) {
			echo "\033[1;37;42m";
			echo 'Hash cycling exists! ';
			echo "\033[0m";
			echo "\n  Strings:\n\t", $strings[$i], "\n\t", $strings[$k];
			echo "\n  Hashes:\n\t", $result[$i], "\n\t", $result[$k], "\n";
		}
	}
}



function generateString($length = 40) {
	$characters = '0123456789abcdefghijklmnopqrstuvwxyz';
	$count = strlen($characters);
	$string = '';

	for ($p = 0; $p < $length; $p++) {
		$string .= $characters{mt_rand(0, $count)};
	}

	return $string;
}