This book constitutes the refereed proceedings of the 8th International Conference on Progress in Cryptology, LATINCRYPT 2023, held in Quito, Ecuador, in October 2023. The 19 full papers included in this book were carefully reviewed and selected from 59 submissions. They were organized in topical sections as follows: Symmetric-Key Cryptography; Multi-Party Computation; Isogeny-Based Cryptography; Discrete Logarithm Problem; Cryptographic Protocols; Real-World Cryptography; and Zero-Knowledge Proofs.