I think it's fine to politely say something like "I'd prefer not to share that information at this point in the process". everyone understands that the applica

I think it's fine to politely say something like "I'd prefer not to share that information at this point in the process". everyone understands that the applicant wants to maximize their salary, but HR folks are humans too. if you say something they perceive as rude, they will probably make a choice that's suboptimal for you and the company.