Ask them what their range is, without telling them your current salary. If they insist, say something like "That's not particularly relevant. It would take $X for me to take the job."
That way you don't have to lie about what your current salary is, but you don't give away information that is not in your best interest to give. You try to get them to give away information, which is great if it works, but you have a next move if it doesn't.
That way you don't have to lie about what your current salary is, but you don't give away information that is not in your best interest to give. You try to get them to give away information, which is great if it works, but you have a next move if it doesn't.