In the information security field there are many of the techniques that make the application secure by exchanging data between two parties. A fair exchange is required for increasing the chances of attack. Hence a new contract signing protocol is proposed based on the OTPK (One Time Private Key) scheme. This protocol will allow two parties to exchange their digital signature between them by signing contract. The proposed protocol ensures fairness such that either both parties receive each other's signatures or neither of them. The proposed protocol uses offline Trusted Third Party (TTP) that will be brought into play only if one party is cheating in other case, the TTP remains inactive.