Security and Communication Networks / 2017 / Article / Tab 2

Review Article

A Survey on Breaking Technique of Text-Based CAPTCHA

Table 2

Comparison of typical methods based on segmentation for breaking nonadherent CAPTCHA.

ExampleSourceSuccess rateReferenceBreaking methodYear

Gimpy-r78%[57]Segmentation: character gap2004
Recognition: distortion evaluation

EZ-Gimpy97.9%[58] Segmentation: connected region2004
Recognition: distortion evaluation

Captcha-service100%[34]Segmentation: vertical projection
Recognition: statistical character pixels
2007

Ego-share92.2%[5] Segmentation: connected region2009
Recognition: SVM

Ge-Captcha100%[59]CW-SSIM2010

Note. SVM: support vector machine, CW-SSIM: complex wavelet based structural similarity.