AlsuhibanyS.A. 2011 Optimising CAPTCHA generation In: the 2011 6th International Conference on Availability, Reliability and Security (ARES ‟11) Vienna, Austria 22-26 August 740 745 IEEE Computer Society Washington, DC, USA
BairdH.S. RiopkaT.P. 2005 ScatterType: a reading CAPTCHA resistant to segmentation attack In: SPIE Document Recognition & Retrieval XII San Jose, CA, USA 16-20 January 5676 Society of Photo Optical, USA
BurszteinE. BethardS. FabryC. MitchellJ.C. JurafskyD. 2010 How good are humans at solving CAPTCHAs? A large scale evaluation the 2010 IEEE Symposium on Security and Privacy (SP '10) Oakland, CA, USA 16-19 May 399 413 IEEE Computer Society, Washington, DC, USA
BurszteinE. MartinM. MitchellJ. 2011 Text-based CAPTCHA strengths and weaknesses In: the 18th ACM Conference on Computer and Communications Security (CCS '11) Chicago, IL, USA October 17-21 October 125 138 ACM, New York, NY, USA
ChellapillaK. LarsonK. SimardP. CzerwinskiM. 2005 Designing human friendly human interaction proofs (HIPs). In: the 2005 SIGCHI Conference on Human Factors in Computing Systems (CHI '05) Portland, OR, USA 2-7 April 711 720 ACM New York, NY, USA
ChewM. BairdH.S. 2003 Baffletext: A human interactive proof SPIE Document Recognition & Retrieval X Santa Clara, CA, USA 20-24 January 5010 305 316 Society of Photo Optical, USA
AhmadEl YanJ. NgW.Y. 2012 CAPTCHA Design: Color, Usability, and Security Internet Computing 16 2 44 51
JiangN. DoganH. 2015 A gesture-based CAPTCHA design supporting mobile devices In: 2015 British Human Computer Interaction Conference (British HCI) Lincoln, UK 15-17 July 202 207 ACM, New York, NY, USA
LeivaL. A. AlvaroF. 2015 captcha: Human Interaction Proofs tailored to touch-capable devices via math handwriting International Journal of Human-Computer Interaction 31 7 457 471
LinR. HuangS. BellG.B. LeeY. 2011 A new CAPTCHA interface design for mobile devices In: the 12th Australasian User Interface Conference (AUIC '11) Perth, Australia 17 – 20 January 117 3 8 Australian Computer Society, Inc. Darlinghurst, Australia
McClellandJ. L. RumelhartD.E. 1981 An interactive activation model of context effects in letter perception: I. An account of basic findings Psychological review 88 5 375
Shirali-ShahrezaS. PennG. BalakrishnanR. GanjaliY. 2013 Seesay and hearsay captcha for mobile interaction In: the 2013 SIGCHI Conference on Human Factors in Computing Systems (CHI '13) Paris, France 27 April - 2 May 2147 2156 ACM, New York, NY, USA
WismerA.J. MadathilK.C. KoikkaraR. JuangK.A. GreensteinJ.S. 2012 Evaluating the usability of CAPTCHAs on a mobile device with voice and touch input In: the 56th Human Factors and Ergonomics Society Annual Meeting Boston, MA, USA 22-26 October 56 1 1228 1232 Sage, Los Angeles, CA, USA
YanJ. AhmadA. S. 2008 Usability of CAP-TCHAs or usability issues in CAPTCHA design In: the 4th Symposium on Usable Privacy and Security (SOUPS‟ 08) Pittsburgh, PA, USA 23-25 July 44 52 ACM, New York