hash_update
The speed difference (as noted in a below posting) between md5() and hash() goes down to zero with strings longer than just a few bytes. With a string length of 1kB the difference is 10% advantage for hash() and shrinks further down to 3% with 10kB strings.
hash
(PHP 5 >= 5.1.2, PECL hash:1.1-1.3)
hash — Generate a hash value (message digest)
Description
string hash ( string $algo, string $data [, bool $raw_output] )Parameters
- algo
Name of selected hashing algorithm (i.e. "md5", "sha256", "haval160,4", etc..)
- data
Message to be hashed.
- raw_output
When set to TRUE, outputs raw binary data. Default value (FALSE) outputs lowercase hexits.
Return Values
Returns a string containing the calculated message digest as lowercase hexits unless raw_output is set to true in which case the raw binary representation of the message digest is returned.
Examples
Example 845. A hash() example
<?php
echo hash('ripemd160', 'The quick brown fox jumped over the lazy dog.');
?>
The above example will output:
ec457d0a974c48d5685a7efa03d137dc8bbde7e3
See Also
| hash_file() |
| hash_hmac() |
| hash_init() |
add a note
User Contributed Noteshash
just me
10-Apr-2007 10:02
10-Apr-2007 10:02
mikael at webhost3 dot eu
10-Mar-2007 01:34
10-Mar-2007 01:34
<?php
$time=microtime(1);
for ($i=0;$i<100000;$i++)
hash('md5', 'string');
echo microtime(1)-$time,': hash/md5<br>';
$time=microtime(1);
for ($i=0;$i<100000;$i++)
md5('string');
echo microtime(1)-$time,': md5<br>';
$time=microtime(1);
for ($i=0;$i<100000;$i++)
hash('sha1', 'string');
echo microtime(1)-$time,': hash/sha1<br>';
$time=microtime(1);
for ($i=0;$i<100000;$i++)
sha1('string');
echo microtime(1)-$time,': sha1<br>';
?>------------------------<br><?php
$time=microtime(1);
for ($i=0;$i<100000;$i++)
hash('md5', $i);
echo microtime(1)-$time,': hash/md5<br>';
$time=microtime(1);
for ($i=0;$i<100000;$i++)
md5($i);
echo microtime(1)-$time,': md5<br>';
$time=microtime(1);
for ($i=0;$i<100000;$i++)
hash('sha1', $i);
echo microtime(1)-$time,': hash/sha1<br>';
$time=microtime(1);
for ($i=0;$i<100000;$i++)
sha1($i);
echo microtime(1)-$time,': sha1<br>';
?>
Gives:
0.33311605453491: hash/md5
1.0671429634094: md5
0.383131980896: hash/sha1
1.3252220153809: sha1
------------------------
0.37684988975525: hash/md5
1.1258299350739: md5
0.43960785865784: hash/sha1
1.3876020908356: sha1
Peter Kelly
29-Jan-2007 12:32
29-Jan-2007 12:32
If the hash functions are not available to you at the moment, and you want to future proof your code, then the code below will emulate two of the important hashing functions, they will also be automatically replaced with the faster versions if available.
if(!function_exists('hash_algos'))
{
function hash_algos()
{
$algo[0] = "md5";
$algo[1] = "sha1";
$algo[2] = "crc32";
return($algo);
}
}
if(!function_exists('hash'))
{
function hash($algo, $data, $raw_output = 0)
{
if($algo == 'md5') return(md5($data));
if($algo == 'sha1') return(sha1($data));
if($algo == 'crc32') return(crc32($data));
}
}
anthony dot parsons at manx dot net
15-Dec-2006 03:08
15-Dec-2006 03:08
These functions are worth using, if only because they're about twice as fast as the built-in counterparts:
<?php
$time=microtime(1);
for ($i=0;$i<100000;$i++)
hash('md5', 'string');
echo microtime(1)-$time,': hash/md5<br>';
$time=microtime(1);
for ($i=0;$i<100000;$i++)
md5('string');
echo microtime(1)-$time,': md5<br>';
$time=microtime(1);
for ($i=0;$i<100000;$i++)
hash('sha1', 'string');
echo microtime(1)-$time,': hash/sha1<br>';
$time=microtime(1);
for ($i=0;$i<100000;$i++)
sha1('string');
echo microtime(1)-$time,': sha1<br>';
?>
Gives:
0.36409902572632: hash/md5
0.79715204238892: md5
0.46680307388306: hash/sha1
1.1121778488159: sha1