Standard phpBB captcha is broken. I modify it such that the user need to add the numbers in captcha images and enter the result (e.g. 1+2+3=6), instead of enter the original characters (e.g. ‘123’).
Enter folder /includes/ucp
edit file ucp_confirm.php: around line 75, find $captcha->execute($row … ) and change to $captcha->execute(‘123’,…)
edit file ucp_register.php:
around line 191 (‘confirm_code’ = > …), change the mimum # of characters to 1 (instead of 5).
around line 489, find $code = gen_rand_string(mt_rand … and change to $code = ‘6’
Enter folder /
edit file posting.php: around line 755, find line if(empty($confirm_row … and change $confirm_row[‘code’] = ‘6’
Enter folder /language/en/common.php, change ‘CONFIRMATION_CODE_EXPLAIN’ strings to ‘Add all the numbers and enter the result’