I like #28 the most out of your entries, so let's build on that one...
I like the shape of the icon because it is like a shield that means protection. Can you try to make the 3 S symbol inside the icon a little more rounded? I don't think it resembles an S enough. Also, I like the combination of Blue, Silver, and White. Can you try to throw some color into the name instead of just Black?
Thanks and keep up the good work!