macm wrote:
> Hi Folks
>
> I tested
>
> <?php
> echo 'sha256=>' .hash('sha256', 'The quick brown fox jumped over the
> lazy dog.') .'</br>';
> echo 'sha384=>' .hash('sha384', 'The quick brown fox jumped over the
> lazy dog.') .'</br>';
> echo 'sha512=>' .hash('sha512', 'The quick brown fox jumped over the
> lazy dog.') .'</br>';
> echo 'ripemd128=>' .hash('ripemd128', 'The quick brown fox jumped over
> the lazy dog.') .'</br>';
> echo 'ripemd160=>' .hash('ripemd160', 'The quick brown fox jumped over
> the lazy dog.') .'</br>';
> echo 'whirlpool=>' .hash('whirlpool', 'The quick brown fox jumped over
> the lazy dog.') .'</br>';
> echo 'tiger128,3=>' .hash('tiger128,3', 'The quick brown fox jumped
> over the lazy dog.') .'</br>';
> echo 'tiger160,3=>' .hash('tiger160,3', 'The quick brown fox jumped
> over the lazy dog.') .'</br>';
> echo 'tiger192,4=>' .hash('tiger192,4', 'The quick brown fox jumped
> over the lazy dog.') .'</br>';
> echo 'snefru=>' .hash('snefru', 'The quick brown fox jumped over the
> lazy dog.') .'</br>';
> echo 'gost=>' .hash('gost', 'The quick brown fox jumped over the lazy
> dog.') .'</br>';
> echo 'adler32=>' .hash('adler32', 'The quick brown fox jumped over the
> lazy dog.') .'</br>';
> echo 'crc32=>' .hash('crc32', 'The quick brown fox jumped over the
> lazy dog.') .'</br>';
> echo 'crc32b=>' .hash('crc32b', 'The quick brown fox jumped over the
> lazy dog.') .'</br>';
> echo 'haval128,3=>' .hash('haval128,3', 'The quick brown fox jumped
> over the lazy dog.') .'</br>';
> echo 'haval256,5=>' .hash('haval256,5', 'The quick brown fox jumped
> over the lazy dog.') .'</br>';
> ?>
>
> As you can see all results are hexadecimal.
>
> Youtube for example have http://youtube.com/watch?v=n5pkDB7zEeo
>
> n5pkDB7zEeo inst hexadecimal so the comparison is simple.
>
> md5 algorithm have 32^16 = 1,2e^24
>
> youtube algorithm have 11^63 = 405e^63 (because is case sensitive so
> combination is [0-9]+[a-Z] + "_" ) (Could have more caracteres!)
>
> So with only 11 caracteres I can have much more combination and much
> less collision.
>
> So how can I create a hash algorithm like youtube? with 11 caracteres
> [0-9]+[a-Z] + "_"
>
> Some tips? How compile?
>
> Cheers
>
> Mario
>

What do y0ou need more than that for? The chances of a collision with
md5 and the rest are VERY remote.

You're much more likely to have a duplicate in the 11 characters than
you will in any of the hashes.

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex@attglobal.net
==================