Ask HN: How do you politely refuse to disclose previous salary information?

In a recent interview, I was asked both how much I made at my last job and what my living costs were. I know not to respond to these things, but this was on a third interview after the interviewer had previously mentioned a couple times that the employees of this company don't care about how much money they get paid.

I ended up revealing both of these things because I felt like I would seem greedy if I didn't. I know this is irrational, but I couldn't think of a clever or polite way to move past the issue.

Does anyone have any advice for handling this type of situation?