A Survey on Breaking Technique of Text-Based CAPTCHA

<table class="figure-group"><tr class="fig-image" id="a"><td><object data="https://static.hindawi.com/articles/scn/volume-2017/6898617/figures/6898617.fig.0011a.svgz" name="6898617.fig.0011a" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(a) </b>The guideline</td></tr><tr class="fig-image" id="b"><td><object data="https://static.hindawi.com/articles/scn/volume-2017/6898617/figures/6898617.fig.0011b.svgz" name="6898617.fig.0011b" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(b) </b>The closed loop detection</td></tr></table>

<div>The example of character structural features in [<a href="/journals/scn/2017/6898617/#B43">46</a>].</div>

Security and Communication Networks

fig11

Figure 11

Figure 11: A Survey on Breaking Technique of Text-Based CAPTCHA 