Digital Self Defense
The idea is to enable online security for individuals/homes/small-businesses using the "self defense" concept (nimble, light, agile and moving with people) instead of being focused on large scale infrastructure (with data centers, firewalls, Security Operations Centers, etc.)
Client want a simple dark colored box with text in one small portion of the box (say, at the bottom, placed asymmetrically. But I'm open to other ideas too.
For Logo design email me at firstname.lastname@example.org
All in all it seems you did a pretty good job laying this out and putting this together. Considering this is a brand piece I'm going to focus most of my critique on the logo. Also in part the rest of it doesn't really need any critique!
The first thing I saw that made me tilt my head and think was the keyhole. It seemed like you would have been able to put the keyhole in the 'D' which would have allowed you to still capture the security aspect yet the 'D' would have still remained functional as a letter.
To a much lesser degree I wasn't exactly sure how I felt about the heat waves coming off of the mug. My initial thought was it's such a bold and vibrant logo but then there are smaller heat wave lines coming off of the mug. Almost as if they were an afterthought? Not to suggest they're necessarily bad or misplaced but they seem to pale in comparison to the rest of the logo.
Unfortunately I wasn't able to see the process beforehand and the logo options you already explored. For all I know you exhausted those options and landed with the best one you could, the one you have now. But if you hadn't I thought it was worth at least mentioning!
All in all it appears you did you homework, laid this out accordingly and ended up with a fantastic design. Besides my logo knit-picking I don't think there is much else I would change about this, kudos!