This book constitutes the proceedings of Cryptographers' Track at the RSAC Conference, CT-RSAC 2026, held in San Francisco, CA, USA, during March 23-26, 2026. The 12 papers included in this book were carefully reviewed and selected from 37 submissions. The papers were organized in topical sections as follows: Systemization of Knowledge (SoK); Homomorphic and Searchable Encryption; RSA and Group Signatures; Post-Quantum Cryptography; Side-Channel and AI Security; and Hash and Zero-Knowledge.