Lecture Notes in Computer Science

This volume continues the tradition established in 2001 of publishing the c- tributions presented at the Cryptographers' Track (CT-RSA) of the yearly RSA Security Conference in Springer-Verlag's Lecture Notes in Computer Science series. With 14 parallel tracks and many thousands of participants, the RSA - curity Conference is the largest e-security and cryptography conference. In this setting, the Cryptographers' Track presents the latest scienti?c developments. The program committee considered 49 papers and selected 20 for presen- tion. One paper was withdrawn by the authors. The program also included two invited talks by Ron Rivest ("Micropayments Revisited" - joint work with Silvio Micali) and by Victor Shoup ("The Bumpy Road from Cryptographic Theory to Practice"). Each paper was reviewed by at least three program committee members; paperswrittenbyprogramcommitteemembersreceivedsixreviews.Theauthors of accepted papers made a substantial e?ort to take into account the comments intheversionsubmittedtotheseproceedings.Inalimitednumberofcases,these revisions were checked by members of the program committee. I would like to thank the 20 members of the program committee who helped to maintain the rigorous scienti?c standards to which the Cryptographers' Track aims to adhere. They wrote thoughtful reviews and contributed to long disc- sions; more than 400 Kbyte of comments were accumulated. Many of them - tended the program committee meeting, while they could have been enjoying the sunny beaches of Santa Barbara.