The book features original research papers presented at International Conference on Cryptology & Network Security with Machine Learning (ICCNSML 2025), organized by Allenhouse Institute of Technology, Kanpur, India during 20–22 December 2025. This conference proceeding provides understanding of core concepts of cryptology and network security with ML in data communication. The book covers research papers in public key cryptography, elliptic curve cryptography, post-quantum cryptography, lattice based cryptography, non-commutative ring-based cryptography, cryptocurrency, authentication, key agreement, Hash functions, block/stream ciphers, polynomial-based cryptography, code-based cryptography, NTRU cryptosystems, security and privacy in machine learning, blockchain, IoT security, wireless security protocols, cryptanalysis, number theory, quantum computing, cryptographic aspects of network security, complexity theory, and cryptography with machine learning.