The term "more secure" is rather ambiguous and could mean many different things in different situations.
As for secure (or security) you need to fully understand the security mechanisms of the server where your board is hosted and the ways that server protects your data.
Whenever I am installing a new board system the first steps to have a "good" security sheme is the way you set-up your servers virtual hosts and he permissions granted to the different pieces of code and server programs. I personally always use (80%) a LEMP stack VPS, and I always make sure to secure the MySql installation. If you have the funds (an extra 5$ a month) I recommend setting up a reverse proxy server that act in between the client you destination server.
Another major security breach (for forums) is the Welcome email-> if your server is setup wrong the email that are sent out have your "real" IP or hosting provider IP. This enables anybody who signs up to your forum to know where your site is hosted.. It is then very easy to signup for an account on the same server and hack your database or fudge your site.
I've seeen it, i've done it. The only way to "secure" you IPB or Xen or Social Eng (etc)installation is to secure the server it resides on.
I also recommend replacing mysql with mariadb on your server.