sattar_aboud2yahoo.com The vast spreading of information in the last decade has led to great development in e-commerce. For instance, e-trade and e-bank are two main Internet services that implement e-transaction from anyplace in the world. This helps merchant and bank to ease the financial transaction process and to give user friendly services at any time. However, the cost of workers and communications falls down considerably while the cost of trusted authority and protecting information is increased. E-payment is now one of the most central research areas in e-commerce, mainly regarding online and offline payment scenarios. In this paper, we will discuss an important e-payment protocol namely Kim and Lee scheme examine its advantages and delimitations, which encourages the author to develop more efficient scheme that keeping all characteristics intact without concession of the security robustness of the protocol. The suggest protocol employs the idea of public key encryption scheme using the thought of hash chain. We will compare the proposed protocol with Kim and Lee protocol and demonstrate that the proposed protocol offers more security and efficiency, which makes the protocol workable for real world services. Keywords: E-payment protocol, Public key cryptography, Signature scheme, Blind signature scheme, Over-spending, E-commerce 1.

Proceedings ISSN (Online): 1985- 2320 This work is subjected to copyright. All rights are reserved whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, re-use of illusions, recitation, broadcasting, reproduction on microfilms or in any other way, and storage in data banks. Duplication of this publication of parts thereof is permitted only under the provision of the copyright law 1965, in its current version, and permission of use must always be obtained from CSC Publishers. Violations are liable to prosecution under the copyright law.

Proceedings ISSN (Online): 1985-2320 This work is subjected to copyright. All rights are reserved whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, re-use of illusions, recitation, broadcasting, reproduction on microfilms or in any other way, and storage in data banks. Duplication of this publication of parts thereof is permitted only under the provision of the copyright law 1965, in its current version, and permission of use must always be obtained from CSC Publishers. Violations are liable to prosecution under the copyright law.