This book constitutes the refereed proceedings of the Cryptographer's Track at the RSA Conference 2025, CT-RSA 2025, held in San Francisco, CA, USA, during April 28-May 1, 2025. The 17 full papers presented in this volume were carefully reviewed and selected from 49 submissions. They were organized in topical sections as follows: Cryptanalysis; Public-Key Cryptography; Hardware and Software Implementations; Symmetric-Key Cryptography; Multiparty Computation and Zero-Knowledge; White-box Crypto. .