Luis von Ahn, Manuel Blum, Nicholas J. Hopper, John Langford. CAPTCHA: Using Hard AI Problems for Security. In Eli Biham, editor, Advances in Cryptology - EUROCRYPT 2003, International Conference on the Theory and Applications of Cryptographic Techniques, Warsaw, Poland, May 4-8, 2003, Proceedings. Volume 2656 of Lecture Notes in Computer Science, pages 294-311, Springer, 2003. [doi]
@inproceedings{AhnBHL03,
title = {CAPTCHA: Using Hard AI Problems for Security},
author = {Luis von Ahn and Manuel Blum and Nicholas J. Hopper and John Langford},
year = {2003},
url = {http://link.springer.de/link/service/series/0558/bibs/2656/26560294.htm},
tags = {security},
researchr = {https://researchr.org/publication/AhnBHL03},
cites = {0},
citedby = {0},
pages = {294-311},
booktitle = {Advances in Cryptology - EUROCRYPT 2003, International Conference on the Theory and Applications of Cryptographic Techniques, Warsaw, Poland, May 4-8, 2003, Proceedings},
editor = {Eli Biham},
volume = {2656},
series = {Lecture Notes in Computer Science},
publisher = {Springer},
isbn = {3-540-14039-5},
}