Coupons are well-known and widely used in the market place to attract new customers looking for deals and to keep loyal customers. Generally speaking, coupons for loyal customers have more discount than coupons for new customers. In order to differentiate between new and loyal customers, we invented two schemes that allow firms to issue different types of e-coupons through a wireless network. The first scheme is used to generate e-coupons that are not assigned to specific customers. Thus, an unused e-coupon can be used by any customer. This scheme is more suitable for attracting new customers. The other scheme is used to generate e-coupons that are assigned to specific customers. Thus, unused e-coupons cannot be used by other customers. This second scheme is more suitable for keeping loyal customers. Both of the proposed schemes are designed for mobile electronic commerce and reduces the cost for processing coupons.
With the rapid growth of computer network technologies, many traditional transactions are conducted electronically. More and more applications such as electronic auction , electronic voting , electronic payments , , and others are developed to run over the Internet. In addition to the Internet, mobile communications revolutions are changing rapidly, and commercial interests abound. Mobile communications, such as Personal Communication Services (PCS) and Universal Mobile Communication System (UMCS), have been developed and have become very popular around the world. The technologies are designed for providing communications and computations with mobility. So far, there are many mobile networks that have been developed, such as GSM, USDC, PDC, and others . The GSM system has now been implemented in more than 70 countries around the world. Furthermore, many applications and services are provided such as wireless application protocol (WAP) , secure teleconferencing , mobile payment system , location-awareness applications , and others. Mobile commerce is being used more widely in business and is becoming a very significant research topic.
In the traditional market place, issuing coupons is a useful and well-known strategy to increase sales. According to the profit line, firms can issue discount coupons to reach new customers. In addition, firms also can issue special coupons with heavy discounts to keep loyal customers. The results of issuing electronic coupons on the Internet are very obvious , . Furthermore, if we can apply the concept of ecoupons to mobile environment, we can anticipate that this will attract more customers to purchase a product. Therefore, the idea of using e-coupons for mobile electronic commerce is raised. The main purpose of using electronic coupons is to make receiving and using coupons mobile for customers. The technology allows a customer to receive an e-coupon through his/her mobile phone. The customer can then forward the ecoupon to the merchant when he/she wants to buy the product.
However, in an electronic environment, information can be intercepted and tampered with easily. Hence, how to build a secure channel for transactions using e-coupons is a key issue in such technology. Therefore, some security requirements are essential to this technology. We summarize the security requirements for using e-coupons as follows:
1) Authentication: In order to prevent a customer from forging e-coupons, the origin of the e-coupons must be ascertained. Thus, a merchant must have the ability to authenticate the validity of all e-coupons received.
2) Integrity: In order to prevent a customer from modifying e-coupons, the integrity of e-coupons must be kept. Thus, a merchant has to ensure that a e-coupon that has been received has not been modified.
3) Preventing repeated use: In order to avoid unlimited use of e-coupons, the number of e-coupons issued should be limited. Therefore, the system must prevent a customer form using the same e-coupon twice.
In addition to the security requirements, the performance of e-coupons is also very important. Due to the small memory space and the low computational capability of mobile electronic equipments, the processing cost of e-coupons, including computational cost, memory space overhead, and communication cost, must be reduced to as low as possible. Therefore, a practical e-coupon system for mobile electronic commerce must be securely performed and efficiently managed with a low processing cost.
In order to satisfy these requirements, some efficient cryptographic techniques such as hash functions can help us to design such an e-coupon scheme. Furthermore, the strategies for issuing e-coupons for new customers or loyal customers may be different. For example, in order to increase sales and attract new customers, firms may wish that a customer can forward an unused e-coupon to another potential customer if the customer does not want to use it. On the other hand, in order to keep loyal customers, firms may issue special ecoupons to loyal customers. The special e-coupons usually have mush more price discounts or offer a product for free. Thus, firms may not wish that the special e-coupons be used by another customer.
According to the two different strategies for issuing coupons, we invented two types of practical e-coupon schemes that satisfy all the requirements. In the first proposed scheme, e-coupons that are issued are not assigned to specific customers. Thus, it can be used by any customer. In the second proposed scheme, e-coupons that are issued are assigned to specific customers. Thus, it cannot be used by other customers. From our knowledge so far, we have not yet found any related schemes for discussing the distinction between e-coupons that are not associated with specific customers, and e-coupons that are associated with specific loyal customers.
The rest of this paper is organized as follows. In Section 2, the technology of message authentication code will be introduced. The technology will be used later in our proposed schemes. The system framework and the notations used throughout the rest of the paper are introduced in Section 3. In Section 4, we present the first proposed scheme for issuing e-coupons which are not assigned to specific customers. In Section 5, we present the second proposed scheme for issuing e-coupons which are assigned to specific customers. In Section 6, the properties and the performance of our schemes are examined. Section 7 concludes this paper.