I know one should not disclose their salary in an interview: how you are valued anywhere else should not affect how the new company should value you, and it can be used against you.
I am aware some people just give a higher figure to prevent it being used against them (stating their supposed current salary as the minimum salary they want in the new position). I would prefer not having to lie, though, but I am not sure I would be able to refuse to disclose it without sounding rude/paranoid.
How can one politely refuse to disclose their salary, ideally without hurting their chances of staying in the interview process?
EDIT: This is not a duplicate of How to respond to a direct ask of salary earned and expectations?: I know how I want to answer, but I do not know how to phrase it in a polite and professional.