This 2-volume set LNCS 15495-15496 constitutes the refereed proceedings of the 25th International Conference on Cryptology in India, held in Chennai, India, during December 18–21, 2024.The 31 full papers presented in these proceedings were carefully reviewed and selected from 96 submissions.They are organized into these topical sections:Part I: Foundations; symmetric-key cryptography; cryptographic constructions; and quantum cryptography.Part II: Cryptanalysis; post-quantum cryptography; and blockchain and cloud computing.