The Study of Three-Party Encrypted Key Exchange Protocol with Time Constraint

• Main Authors: Hsien-Yun Chuang, 莊賢耘
• Other Authors: Hsing-Chung Chen
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/02822532968333483963

碩士 === 亞洲大學 === 資訊工程學系碩士班 === 98 === In 2004, Chang et al. proposed a new 3PEKE (three-party encrypted key exchange) scheme which is without using the server's public keys. However, in 2008, both Yoon et al. and Chen et al. showed that Chang et al.’s scheme cannot resist undetectable on-line password guessing attacks. And then, Yoon et al. and Chen et al. respectively proposed a new approach to solve Chang et al.'s problem of security. But in 2009, Lo et al. proved that both Yoon et al. and Chen et al. cannot effectively prevent undetectable on-line password guessing attacks and then proposed an improved approach. Although they actually propose an improved approach, the clients who act as the roles of exchange-message are quite different from the traditional 3PEKE schemes. That is, a client will still act as the intermediate role who exchanges the messages between the other one and server. In other words, both clients will exchange messages with server, individually. Thus, we propose three approaches, which are called a 3PEKE Protocol with Protected Password Authentication (3PEKE-PPA), an Enhanced 3PEKE Protocol Using Digital Time-Stamp (3PEKE-DTS) and an Enhanced 3PEKE Protocol with Time Bound (3PEKE-TB), to improve the traditional 3PEKE schemes. Our scheme can achieve effectively implement and resist undetectable on-line password guessing attacks and strengthen the 3PEKE system of security.