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PHP – Generate an 8 character hash from an integer

Posted by: admin July 12, 2020 Leave a comment


Is there a way to take any number, from say, 1 to 40000 and generate an 8 character hash?

I was thinking of using base_convert but couldn’t figure out a way to force it to be an 8 character hash.

Any help would be appreciated!

How to&Answers:

Why don’t you just run md5 and take the first 8 characters?

Because you are wanting a hash, it doesn’t matter whether portions are discarded, but rather that the same input will produce the same hash.

$hash = substr(md5($num), 0, 8);


>>> math.exp(math.log(40000)/8)

Therefore you need 4 digit-symbols to produce a 8-character hash from 40000:

sprintf("%08s", base_convert($n, 10, 4))


For php:

$seed = 'JvKnrQWPsThuJteNQAuH';
$hash = sha1(uniqid($seed . mt_rand(), true));

# To get a shorter version of the hash, just use substr
$hash = substr($hash, 0, 10);



there are many ways …

one example

$x = ?
$s = '';
for ($i=0;$i<8;++$i)
    $s .= chr( $x%26 + ord('a') );
    $x /= 26;


$hash = substr(hash("sha256",$num), 0, 8);


So you want to convert a 6 digit number into a 8 digit string reproducibly?

sprintf("%08d", $number);

Certainly a hash is not reversible – but without a salt / IV it might be a bit easy to hack. A better solution might be:

substr(sha1($number . $some_secret),0,8);