Picture CAPTCHAsWith Sequencing: Their Types and Analysis
Aditya Raj, Ashish Jain, Tushar Pahwa, Abhimanyu George Jain · International Journal for Digital Society · 2010
CAPTCHAs are employed on web systems to differentiate between human users and automated programs which indulge in spamming and other fraudulent activities.CAPTCHAs currently in use have been broken and rendered ineffective as a result of continuous evolution in CAPTCHA breaking.Thus, there is a need to employ stronger CAPTCHAs to keep these breaking attacks at bay while retaining ease of implementation on websites and ease of use for humans.In this paper, we introduce Sequenced Picture Captcha (SPC).Each CAPTCHA round comprises of object pictures, each of which may be accompanied by a Tag.The user is required to determine the logical sequence of the displayed object pictures based on the Tags.We identify two generation schemes -one in which object pictures indicate an inherent sequencing and one in which explicit Tags are displayed for determining the sequencing.We also analyze all these schemes.The advantages of high user convenience and simplicity of operation are retained in both generation types.