I don't know what lithander was going for with realistic vs accessible, but I think one thing that would help is to make sure the game makes sense to people who have zero hacking/computer experience. One example I can think of is that I have very little idea of what you mean by data exfiltration. It might help to have the system be simplified so that you maintain the higher levels of hacking and nix some of the details, or to just use longer (but more plain english) names for hacking techniques.
I think the website example is a good entry level idea of what I was thinking of, where the thought process could be where the player
- notices address bar
- realizes variables within address
- recognizes common word variable (such as "balance")
- changes values
You could honestly have a whole experience wrapped around address bar nonsense, where the first levels have really simple "balance=x" scenarios, and by the end they are extracting hashed data from URLs, but I'm getting ahead of myself. The step that is important is the step between recognition and change. In puzzler terms, its the step where the player knows the problem space entirely (goals included) and the step where the player teases out the path to the goal.
If I knew more about hacking, or really anything at all about hacking, I would give an extra example, but the URL example is pretty spot on. I guess another one would be like how Heartbleed (?) worked, where it would do array overflow to access someone's stuff, but that's much more high skill.
The main reason I brought up the versus thing is because I'm doing a project about competitive gameplay and the concept of Yomi (basically three thoughts ahead) is super ingrained in my mind right now.