Trying to find out what the series was where there was a child that created 'Guard dog programs" and another something called the 'dragon?' I remember a bank being involved in the first part of the book but that's about all.
Per KHW's comment above, I think the book you're referring to is Ender's Game by Orson Scott Card.
There's an explicit reference to "Genius Children";
"Very funny." Mother said. "I try to be concerned, but it makes no difference to my genius children.”
Ender creates a Security system which he gives out to his friends;
Alai grinned. "I just got in and trashed somebody's files. He's right behind me on cracking the system. I need protection, Ender. I need your system.” "If I give you my system, you'll know how I do it and you'll get in and trash me.” "You say me?" Alai asked. "I the sweetest friend you got!” Ender laughed. "I'll setup a system for you.”
Ender commands the Dragon army;
Dragon, said the form. There was no Dragon Army. "I've never heard of Dragon Army," Ender said. "That's because there hasn't been a Dragon Army in four years. We discontinued the name because there was a superstition about it"..."Well, why are you reviving it now?” "We had a lot of extra uniforms to use up.”
The bank reference is a bit harder to clear up. There is a mention of Ender having "plenty of salary that [he] never used, sitting around in banks" but that's right at the end of the book. More likely you're thinking of Ender's sister and brother needing their father's citizen card in order to falsify their identities on the internet.