Public asking for my name?

Not a peace or police officer. No Department policy in place that I'm aware of. We often get random people seeing us sitting in our marked vehicles and they ask us for our name or "name and badge number". I always ask them where it says I have to give it to them and usually get a non answer or "it's state law" and then I say, "ok, cool, tell me where it says that and I'll gladly comply with the law". Does it actually say it anywhere? Public Officers Law?

Obviously I have to wear my state issued ID when walking into a state office building, but this isn't what I'm talking about. I'm talking about being parked at any random spot and a random person coming up to my car. Our agency is hated, so it happens often to myself or my coworkers. Just curious.