一种安全实用的三层动态验证码,创造性地将单帧零知识理论与生物视觉理论结合了起来,既保证了任一单帧都很难识别,又能确保人眼易于识别。充分利用了计算机在复杂背景下对多个运动物体进行识别的弱点,确保了计算机程序利用多帧仍很难破解。分层结构使得验证码的设计更为清晰,具有很强的扩展性和很大的优化空间。 A safe and practical three-layer dynamic verification code, which creatively combines the theory of single-frame zero-knowledge with biological vision theory, not only ensures that any single frame is difficult to identify, but also ensures the human eye is easy to recognize. Make full use of the computer in a complex background to identify a number of moving objects weaknesses to ensure that the use of multi-frame computer program is still difficult to crack. Hierarchical structure makes verification code design more clear, with strong scalability and a lot of space for optimization.