What effects do Prestige and Security have on my keep?

I just got control of my keep and started the first upgrades. Each upgrade has a Prestige and a Security value associated with it. From what I understood, upgrading my keep might draw attention and I'll have to keep security in mind.

How exactly does this work, and what are the effects of Prestige and Security?

Solution 1:

Prestige increases taxes collected, and the likelihood of various positive special events triggering for your keep.

Security reduces taxes lost to banditry, and the likelihood of various negative special events triggering for your keep.

You'll want to keep the two in balance to maximize income.