Description:This book constitutes the refereed proceedings of the Cryptographers’ Track at the RSA Conference 2005, CT-RSA 2005, held in San Francisco, CA, USA in February 2005.The 23 revised full papers presented together with 2 invited papers were carefully reviewed and selected from 74 submissions. The papers are organized in topical sections on cryptanalysis, public key encryption, signature schemes, design principles, password-based protocols, pairings, and efficient and secure implementations.