The whole point of cryptography is to solve problems. Cryptography solves problems that involve secrecy, authentication, integrity, and dishonest people. You can learn all about cryptographic algorithms and techniques, but these are academic unless they can solve the problem. This is why we are going to look protocols first. A cryptographic protocol is a protocol that uses cryptography. Cryptography is an art and science of keeping messages secure. A cryptographic protocol involves some cryptographic algorithm, but generally the goal of the protocol is something beyond simple secrecy. Zero knowledge proof is an advanced cryptographic protocol. This is an interactive proof between prover and verifier. The prover convinces her knowledge to verifier and the verifier verifies it. This is the strategy using in zero knowledge proof. Due to the potential advantages of public key cryptography, Many researchers are hard at work, and some algorithms have already been published. One good method -RSA- was discovered by a group at M.I.T. Here introducing the RSA algorithm and explains the zero knowledge proof of the ability to break RSA.