Cynthia Dwork, Andrew Goldberg, Moni Naor. On Memory-Bound Functions for Fighting Spam. In Dan Boneh, editor, Advances in Cryptology - CRYPTO 2003, 23rd Annual International Cryptology Conference, Santa Barbara, California, USA, August 17-21, 2003, Proceedings. Volume 2729 of Lecture Notes in Computer Science, pages 426-444, Springer, 2003. [doi]
Abstract is missing.