In the world of internet, e-commerce is one of the most prominent sectors where user wants to shop and pay online for online products. E-cash is one of these payment methods. In e-cash, every time a unique string is generated for user so that user uses that string to pay for any online product. At the time of online purchasing a trust should be maintain between customers and merchant such that the product price which is going to pay by customer is fair or not, the merchant is indeed genuine to deliver the product after getting online payment or not. Trust issues are resolved by using fair exchange concept at the time of online purchasing. Anonymity is also a major concern; it means that true identity of users must be hidden from merchant. By keeping these issues in mind we proposed a protocol which ensures users anonymity by using e-cash payment method and fair exchange by using off-line TTP which invokes by customer when any dispute occur from merchant side. In this paper, we implement our proposed protocol and also analyze its performance and compare it with other protocol.