Verification process many times is a bidirectional process, that is, part A claims something, part B poses a riddle in response (like asking for user name and password, sending a verification Email, etc.), part A solves the riddle.
This is the only way that B can get sure A is what he claims to be. The most simple case is authentication where you are asked to provide user name and password for a website.
But authentication for an employee of a company is not possible without a third party, which in this example is the company owner, and of course, first you should trust company owner. For example, consider IBM as one of your clients. IBM CEO signs up in your website and you become sure that he/she is the real CEO of IBM. From now on, since you trust this third party, anyone coming to your site with the claim that he/she works for IBM, can be verified with the help of CEO.
Your business requirement is just like Certificates. A visitor to site foo.com wants to get sure that the site is trustworthy enough for online payments. How visitor can get sure about this? He sees a certificate notification at the address bar (in case of HTTPS protocol). But is that enough? Of course not. Because up to here, there are only two parties involved in the verification maze and second party (website) can claim a certificate. The only brilliant point here is that, visitor should trust a third party to verify the certificate of the website foo.com.