Md5 execution time?

[Tree]

Anyone know how long (on average) generating the md5 hash of a string takes?

I ask because I'm generating the md5 hash of the md5 hash of a base64_encoded string. Would that take a long time?

 

[nasaboy007]

erm... i dont know the number offhand but u cud always run a test by having php take the time first, then run through the md5 hash making process and then take the time again, find the difference, and echo it.

 

[Tree]

I don't need the exact number, I just need to know if it is feasable to do this, or if it would put too much stress on the server and/or take too long. I know that base64_encoding the same string three times in a row takes quite a bit of time.

 

[MasterB]

Barely any time at all... you can see a test here (see the end result at the very bottom of this post):

Without encoding/double hashing: http://y1v.net/timer2.php
With encoding/double hashing: http://y1v.net/timer.php

This is running on a standard linux server configuration.

Source of timer2.php:

<?php 

// Brendan Bates
// www.multibb.net

$timeparts = explode(' ',microtime());
$thetime = $timeparts[1].substr($timeparts[0],1);

$string = "This is a string to be base 64 encoded.";

$timeparts = explode(' ',microtime());
$starttime = $timeparts[1].substr($timeparts[0],1);
$timeparts = explode(' ',microtime());
$endtime = $timeparts[1].substr($timeparts[0],1);
echo "<b>Exec Time:</b> ";
echo bcsub($endtime,$starttime,6);

echo "<br>";
echo "Final String: ";
echo $string;

?>

Source of timer.php:

<?php 

// Brendan Bates
// www.multibb.net

$timeparts = explode(' ',microtime());
$thetime = $timeparts[1].substr($timeparts[0],1);

$string = "This is a string to be base 64 encoded.";
$string = base64_encode($string);
$string = md5(md5($string));

$timeparts = explode(' ',microtime());
$starttime = $timeparts[1].substr($timeparts[0],1);
$timeparts = explode(' ',microtime());
$endtime = $timeparts[1].substr($timeparts[0],1);
echo "<b>Exec Time:</b> ";
echo bcsub($endtime,$starttime,6);

echo "<br>";
echo "Final String: ";
echo $string;

?>

End Result: (on an average of 10 loads) about 0.00003 seconds different. Hope that helps you out .

I had this from an experiment I did a while back. So, from what I've concluded, it shouldn't put barely any extra stress on your server at all.

 

[Tree]

Alright, thank you very much!



Upon testing, it appears my server's a bit slower. I modified the code to measure what I'm encoding. It will be used as part of a unique ID.

$string = md5(md5(base64_encode($_SERVER['PHP_SELF'])));

With double hashing/md5
http://www.vestieo.com/Noname1.php

Without
http://www.vestieo.com/Noname1.php?hsdfnjkeraiuy43y89

Should this make any huge difference?

 

[Jim_]

Is it really necessary to encode it that many times?
md5("salt".$_SERVER['PHP_SELF']); would be just as secure and take less (but barely noticable) time to execute.

 

[MasterB]

I don't know if you take Algebra 2 or Chemistry, but 2.264E-05 = 0.00002264 seconds (just to let you know :P). And honestly, the md5 algorithm is extremely efficient. I don't know about base64 that much, but it seems pretty efficient also. Shouldn't make much difference at all.

 

[Tree]

I don't know if you take Algebra 2 or Chemistry

Took it, never used it since.

Alright, thanks guys.

Is it really necessary to encode it that many times?

Well, not really. :p

 

[cx409]

Hmm...one thing to say: Very, very, very fast. Much, much, much faster than you can say "encrypt!"