期刊名称：International Journal of Computer Science & Technology
印刷版ISSN：2229-4333
电子版ISSN：0976-8491
出版年度：2016
卷号：7
期号：1
页码：174-176
语种：English
出版社：Ayushmaan Technologies
摘要：CAPTCHA is a program or a system that protects against automated scripts (or bots). It generates tests that humans can pass but computer programs cannot. CAPTCHA systems are widely used nowadays for protecting and providing security to internet based services for humans from abuse by bots. Different types of CAPTCHA technologies are discussed in this paper and a detailed analysis on their reliability is performed. Subsequently, a new CAPTCHA technique is proposed which is based on facial expression detection.
