Human-Centered Design (HCD), in my experience, has had a few ups and downs but mostly all ups. Why would a security-minded individual look to HCD? I'm sure glad you've asked that question, as I could probably write some more content about my favorite tools or "tricks of the trade" styled content. Although those are fun areas to write about, design challenges spurred by HCD have caused me to refocus on what matters most: Humans.
It's pretty easy to look at a system design and shut down every insecure item I can flag within it. It's much more difficult to fully understand the challenges faced before the specified design even reached me for inspection and approval. It's much more difficult to weigh risks while factoring in your human counterparts and the need to have something completed by a deadline. Not to worry, HCD has arrived! Design Challenges allow all of the teams to participate, gather data, understand/identify needs, identify pain points, and ultimately give input towards solutions to those problems.
Was it clear? Did you catch it? If not, it's ok. I had to experience HCD by doing design challenges to understand it all better myself. What changed was the early intervention and commitment to participate in the challenges and end up with solutions where I didn't have to evaluate how something made it to me. I was part of the solution and could give input early on. My analysis was presented in real-time to all participants in the design challenge.
The downside? Time! How do I fit something time-consuming into my already jam-packed schedule? Our Human Experience (HX) Team has made this less of a pain point by organizing, coordinating, and being highly flexible with schedules that vary across teams. If you've not joined any design challenges in your work environment, I highly recommend you do. Another downside one can experience when the values of HCD are misguided and directed in a non-inclusive manner is feeling shut out and shut down. I've chosen not to shame the group I've experienced this with but beware, some groups drive a vastly different narrative to HCD than meets the eye.
I'll conclude with the following advice: jump headfirst into a design challenge if offered, and enjoy the new experience if it's your first time or if it's not. You've gained some experience; make it the best first time for another team member, and you'll be shocked with how excellent the solutions are!