摘要
针对验证码的本质特征、形式化定义、今后发展方向和研究重点等问题,通过深入、细致地分析和研究现有大量验证码,给出了验证码的本质特征描述及形式化定义,并从信息类型分类(共五种)、识别方式分类(共两种)和交互性分类(共两种)三个维度给出了验证码的20个种类;分析了20种验证码类型的技术特点,研究了其攻防对策,给出了各类验证码今后的研究重点、难点及其研究方向。重点探讨了动态验证码和隐性验证码(包括语义验证码),特别针对验证码通用攻击的攻防对策,提出了验证码领域的一些新思路和新研究方法。
About the problem of essential characteristics, formal definition, new direction and research key of CAPTCHA, through a lots of analysis of the known CAPTCHA, this paper discussed the essential characterize and form^tl definition of CAP- TCHA. It proposed the 20 varieties of CAPTCHA by three dimensions of information classification （5 varieties）, recognized method classification （2 varieties）, and interaction type classification （2 varieties）, and gave technical characteristics analy- sis, attach and strategy research, keys and directions of the 20 varieties. Then it discussed the dynamic CAPTCHA and im- plicit CAPTCHA（ including semantic CAF^CHA） , specially proposed about the general CAFFCHA attach, some new idea and new method of CAPTCHA.
出处
《计算机应用研究》
CSCD
北大核心
2013年第9期2776-2779,共4页
Application Research of Computers
基金
公安部应用创新项目(2011YYCXGADX126)
