I don't really see the point of not telling them, if the company has no idea about your previous salary, they aren't going to be tricked into offering you some huge number,
they are going to come in at the average wage in your location for that position.
What you should do instead is identify the number you want to get paid before hand. ( Which should be higher than the average )
And then honestly tell them , I'm currently paid X, but am looking for a job that pays Y.
If they say they can't do that, its too big of jump or whatever, just say that you understand and thanks and move on to the next company
If you're going to do this, you should leave out X. The larger the differential between X and Y, the higher the unconscious (or perhaps even conscious) bias will be against you. "This guy wants a 40% raise to come work for us" vs. "This guy wants $Y to come work for us."
This assumes that the person looking for work has more leverage in negotiations. If a person really needs the job, they can't just walk away over a drop in salary.
What you should do instead is identify the number you want to get paid before hand. ( Which should be higher than the average ) And then honestly tell them , I'm currently paid X, but am looking for a job that pays Y.
If they say they can't do that, its too big of jump or whatever, just say that you understand and thanks and move on to the next company