Any of the three are only as secure as your code. You can't base your opinions on who uses what, it's how they use it, and how it was written that counts.
You'll probably find many banking sites use asp because they have deals with Microsoft for their server products and support, not because of security concerns. They could also be using packages particular to their industry, which were written for asp specifically too.
I can't speak for asp, as I have no experience of working with it, but my site's written in php, and I'm pretty confident it's secure, and works as I want it to, it's open source (free) and well documented and supported. Learn to write secure code and it's all you need.
As for jsp, forget it, x10 doesn't support it, so there's little point you exploring that avenue if your site's hosted here.