Table 4 Typical video-based CAPTCHAs
From: Human-artificial intelligence approaches for secure analysis in CAPTCHA codes
CAPTCHA | Illustration | Challenge | Feature |
|---|---|---|---|
Motion CAPTCHA [55] |
| Choose the sentence that best describes the person's movement in the video | Semantic, limited video database, human craft |
Kluever el al [54] |
| After watching a video, provide three words that best describe it | Semantic, limited video database, human craft |
