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TAPCHA: An Invisible CAPTCHA Scheme.

Jiang, N. and Dogan, H., 2018. TAPCHA: An Invisible CAPTCHA Scheme. In: 32nd International BCS Human Computer Interaction Conference, Interactions Gallery, 2-5 July 2018, Belfast.

Full text available as:

TAPCHA - An Invisible CAPTCHA Scheme - BHCI-2018_paper_212.pdf - Accepted Version
Available under License Creative Commons Attribution Non-commercial No Derivatives.



TAPCHA is a universal CAPTCHA scheme designed for touch-enabled smart devices such as smartphones, tablets and smartwatches. The main difference between TAPCHA and other CAPTCHA schemes is that TAPCHA retains its security by making the CAPTCHA test ‘invisible’ for the bot. It then utilises context effects to maintain the readability of the instruction for human users which eventually guarantees the usability of the scheme. Two reference designs, namely TAPCHA SHAPE & SHADE and TAPCHA MULTI are developed to demonstrate the use of this scheme.

Item Type:Conference or Workshop Item (Paper)
Uncontrolled Keywords:CAPTCHAs; Smart devices; Smartphones; TAPCHA; Usability; Security; Context effect
Group:Faculty of Science & Technology
ID Code:30953
Deposited By: Symplectic RT2
Deposited On:09 Jul 2018 08:58
Last Modified:14 Mar 2022 14:11


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