From: Roland Haeder Date: Sat, 21 Mar 2015 20:58:26 +0000 (+0100) Subject: Commented added switch to MHASH_SHA256 + 5-times hashing and some other improvements. X-Git-Url: https://git.mxchange.org/?a=commitdiff_plain;h=a3f391f5923305b5a612b329e4fef26bb3db0d6b;p=core.git Commented added switch to MHASH_SHA256 + 5-times hashing and some other improvements. Signed-off-by: Roland Häder --- diff --git a/contrib/chash/chash.php b/contrib/chash/chash.php index 408b4660..c37216ab 100644 --- a/contrib/chash/chash.php +++ b/contrib/chash/chash.php @@ -4,14 +4,24 @@ error_reporting(E_ALL | E_STRICT); define('START_TIME' , microtime(TRUE)); define('CHECK_POINT' , 'chash.pos'); +// Hashes needed to complete a "block" $GLOBALS['block_size'] = 100; $GLOBALS['none_increment'] = (1 / pow(10, 20)); -$GLOBALS['hash_algo'] = MHASH_RIPEMD320; + +// Hashing algorythm +$GLOBALS['hash_algo'] = MHASH_SHA256; + +// Automatic saving interval in seconds $GLOBALS['flush_file_time'] = 30; + +/* + * How long (in seconds) to try to find a proper hash until the best root hash + * is taken. + */ $GLOBALS['restart_search_time'] = 1800; // Hashes per call -$GLOBALS['hash_cycles'] = 3; +$GLOBALS['hash_cycles'] = 5; // Total restarts $GLOBALS['total_restarts'] = 0; @@ -73,6 +83,9 @@ function modulaHash ($hash1, $hash2) { // Both must have same length assert(strlen($hash1) === strlen($hash2)); + // Init propability array with 256 zeros + $propability = array_fill(0, 256, 0); + // Init new hash $modulaHash = ''; @@ -85,6 +98,9 @@ function modulaHash ($hash1, $hash2) { $part1 = hexdec(substr($hash1, $idx, 2)); $part2 = hexdec(substr($hash2, $idx, 2)); + // Debug message + //* NOISY-DEBUG: */ print 'part1=' . $part1 . ',part2=' . $part2 . PHP_EOL; + /* * If part1 is larget part2, part1 is divident and vise-versa. But don't do it * if one is zero @@ -92,18 +108,43 @@ function modulaHash ($hash1, $hash2) { if (($part1 > $part2) && ($part2 > 0)) { // 'part1' is larger than 'part2' $mod = $part1 % $part2; - } elseif (($part1 < $part2) && ($part1 > 0)) { + } elseif (($part2 > $part1) && ($part1 > 0)) { // 'part2' is larger than 'part1' $mod = $part2 % $part1; } - // "Invert" the result against 255 + // $mod is now mostly a small number so try to "improve" it + //* NOISY-DEBUG: */ print 'mod[' . gettype($mod) . ']=' . $mod . ' - BEFORE!' . PHP_EOL; + $mod = (int) round(sqrt($mod * ($part1 + $part2 + $mod ^ 7) / 3)); + //* NOISY-DEBUG: */ print 'mod[' . gettype($mod) . ']=' . $mod . ' - AFTER!' . PHP_EOL; + + // Make sure it is valid + assert($mod >= 0); + assert($mod <= 255); + + // "Invert" the result against 255 as zeros are not good for later calculations $mod = 255 - $mod; + // Add it to propability array for debugging + $propability[$mod]++; + // Encode to hex, pre-pad it with zeros and add to new hash $modulaHash .= padHex($mod); } // END - for + // Debug propability array + $cnt = 0; + foreach ($propability as $value) { + // Is the value larger than one, means the number has been found at least once? + if ($value > 0) { + // Then count it + $cnt++; + } // END - if + } // END - foreach + + // Debug message + //* NOISY-DEBUG: */ print('cnt=' . $cnt . '/' . strlen($hash1) / 2 . PHP_EOL); + // Modula hash must have same length as input hash assert(strlen($modulaHash) === strlen($hash1));