Best way to generate 50~150 character long key

[Mudsaf]

Hello, i'm wondering which is best method to make account recovery key? Wondering is MD5 with random integer from 1-100k + some text there be good?

[Ingolme]

Probably using an alphabet and a random set of characters.

function generate_key($key_length, $alphabet) {    $limit= strlen(alphabet) - 1;    $key = '';    for($i =  0; $i < key_length; $i++) {        $key .= $alphabet[mt_rand(0, $limit)];    }return $key;}// Generate the key with a particular alphabet$len = 150;$a= 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'generate_key($len, $a);

[Mudsaf]

Thanks