Design and Implementation of Character CAPTCHA based on Contraction Mapping

摘要：

APTCHA is an important means to improve network security and prevent hackers.Since only a simple transfigure processing and the same style.CAPTCHA are lack of security and have a high rate to be cracked.Hence it is important for network security to design a new method of transfigure having random and complex feature.The paper creates an algorithm using contraction mapping principle and fixed point, with a way of circumvolution and translation.The algorithm randomly select a fixed point in the character picture and make a transfigure using fixed point principle.The experimental results show that the CAPTCHA based on contraction mapping has a strong randomness and difficult to be recognized b)f computer programs, which can provide a strong security for Web applications.

关键词： contraction mapping fixed point character merging Transfiguration

作者: Wang Nan

作者单位: School of Mathematical Science,Heilongjiang University,Harbin 150080,China

会议类型: 国际会议

会议名称: 2011 2nd International Conference on Material and Manufacturing Technology(2011第二届材料与制造技术国际会议 ICMMT2011)

会议地点: 厦门

会议语种:英文

页码: 731-736

在线出版日期: 2011-07-08（万方平台首次上网日期，不代表论文的发表时间）