I saw the landing page. The first step is to identity the right buyer personas. This post may help you: http://contentmarketinginstitute.com/2015/04/content-marketing-personas/. It helps you identify the right audience and their pain points that resonate with your solution/service.
Next, make an inventory for "online resources where people are talking about their security-related issues". It can be quora, WP forums, Drupal community, and elsewhere. You can also use BuzzSumo or even Mention to find your audience is talking about. Then, write a series of first few posts. Try to address one problem in one post. Remember that content marketing is 20% writing and 80% distribution/promotion. At this stage, you can start contributing by answering their questions (Quora, forums, or anywhere) and give a link back to the relevant blog post that you published.
Make an inventory of Influencers who talk or write in the same industry as of your product. Engage, listen, and thank them if you like their work. After the first stroke of engagement, identify whom you can write to seek advice. This post by Alex shares some useful pointers: https://www.groovehq.com/blog/influencer-outreach-mistakes
The above points were most of the homework. Now comes the content strategy. Make an inventory of what all content types you need. For example, blog posts, industry news (curated), webinars, tutorials, some event sponsorship opportunities, product features, the team, and so on. Do a market research for how your competitors are doing and perform a "Gap Analysis". Find the differentiators that you can offer "via content" and write/share/promote it to your strength.
When you identify personas and their pain points, and the sources where they are sharing their concerns (Quora and others), they cannot overlook your value proposition if you share it with a purpose, and strongly enough.