I am studying about the zero knowledge proofs and I am looking for a practical (example based) approach to undrestand its process. I have studied the theory a little bit and I find it interesting yet confusing.
My exact question is given a prover A and verifier B. How can prover A prove that he is in the possession of some value 'X' without disclosing 'X' to B. 'X' could be A's last name or A's telephone number.
I am trying to compare this approach with commitment schemes (i.e. Hashing 'X' and comparing the hashes). I know that in the commitment schemes the value 'X' must be shared with B.