TY - GEN
T1 - Re
T2 - 19th USENIX Security Symposium
AU - Motoyama, Marti
AU - Levchenko, Kirill
AU - Kanich, Chris
AU - McCoy, Damon
AU - Voelker, Geoffrey M.
AU - Savage, Stefan
N1 - Funding Information:
We would like to thank the anonymous reviewers and our shepherd, Rachna Dhamija, for their feedback as well as Luis von Ahn for his input and discussion early on in the project. We also thank Jonathan Wilkins for granting us access to reCaptchaOCR, Jon Howell and Jeremy Elson for discussions about the Asirra CAPTCHA, and the volunteers who assisted in manual identification of targeted CAPTCHAs. We are particularly indebted to MR. E for his generosity and time in answering our questions and sharing his insights about the technical and business aspects of operating a CAPTCHA-solving service. Finally we would also like to thank Anastasia Levchenko and Ilya Kolupaev for their assistance. This work was supported in part by National Science Foundation grants NSF-0433668 and NSF-0831138, by the Office of Naval Research MURI grant N000140911081, and by generous research, operational and in-kind support from Yahoo, Microsoft, HP, Google, and the UCSD Center for Networked Systems (CNS). McCoy was supported by a CCC-CRA-NSF Computing Innovation Fellowship.
Publisher Copyright:
copyright © 2010 USENIX Security Symposium.All right reserved.
PY - 2010
Y1 - 2010
N2 - Reverse Turing tests, or CAPTCHAs, have become an ubiquitous defense used to protect open Web resources from being exploited at scale. An effective CAPTCHA resists existing mechanistic software solving, yet can be solved with high probability by a human being. In response, a robust solving ecosystem has emerged, reselling both automated solving technology and real-time human labor to bypass these protections. Thus, CAPTCHAs can increasingly be understood and evaluated in purely economic terms; the market price of a solution vs the monetizable value of the asset being protected. We examine the market-side of this question in depth, analyzing the behavior and dynamics of CAPTCHA-solving service providers, their price performance, and the underlying labor markets driving this economy.
AB - Reverse Turing tests, or CAPTCHAs, have become an ubiquitous defense used to protect open Web resources from being exploited at scale. An effective CAPTCHA resists existing mechanistic software solving, yet can be solved with high probability by a human being. In response, a robust solving ecosystem has emerged, reselling both automated solving technology and real-time human labor to bypass these protections. Thus, CAPTCHAs can increasingly be understood and evaluated in purely economic terms; the market price of a solution vs the monetizable value of the asset being protected. We examine the market-side of this question in depth, analyzing the behavior and dynamics of CAPTCHA-solving service providers, their price performance, and the underlying labor markets driving this economy.
UR - http://www.scopus.com/inward/record.url?scp=85076285223&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85076285223&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:85076285223
T3 - Proceedings of the 19th USENIX Security Symposium
SP - 435
EP - 452
BT - Proceedings of the 19th USENIX Security Symposium
PB - USENIX Association
Y2 - 11 August 2010 through 13 August 2010
ER -