If this is correct, then it would be risky for someone to lie to a new employer about their former salary in order to receive an offer for a higher pay, because the new employer could use this service to cross check the employee's claims.
You don't need to lie. There's nothing wrong with saying "My current salary is $xxxxx, but I feel that my employer undervalues my skills so I want $yyyyyy. It's why I'm leaving my current role." There is no reason why your future salary has to be based on your current salary. If the employer you're negotiating with disagrees then walking away is the best option because they undervalue your skills too.
If you want to actually get paid more, get two competing offers. Or you can try the strategy of not lying and just telling the new employer, 'I'm not going to tell you my previous salary.' The downside is that this clearly signals to the employer that you weren't making very much before and you are fishing for a big raise.
This kind of goes against conventional wisdom, but I actually don't think that switching jobs is the strongest time to ask for more money. I think it's after you have gotten into a role, are killing it, and adding crazy value to the company. That's when you actually have a lot of leverage to say 'hey, I love what I'm doing here and I should be paid a lot more'.