We really appreciate you providing insight into how you went about developing the logo. Of the three, we like #1 the most. We like the placement of the words (not stacked), and think that a white background would work best.
We like the idea of an icon and feel that the shield works, as it ties in with the idea of a defender and being secure, but think that the design of it could be different. The "d" inside the shield isn't quite resonating with us. I am obvioulsy not a designer, though, so am finding it difficult to articulate why.
Please let me know if I can provide you with any more information - I will do my best! Thak you again for your work, and we look forward to seeing more!