Cryptanalysis & Quantum Cryptanalysis -- Enhancing the Related-Key Security of PIPO through New Key Schedules -- Distinguisher and Related-Key Attack on HALFLOOP 96 -- Revisiting Key Switching Techniques with Applications to Light-Key FHE -- Optimized Quantum Implementation of SEED -- Depth-Optimized Quantum Implementation of ARIA -- Finding Shortest Vector using Quantum NV Sieve on Grover -- Experiments and Resource Analysis of Shor's Factorization Using a Quantum Simulator -- Quantum Circuits for High-Degree and Half Multiplication For Post-Quantum Analysis -- Side Channel Attack -- Extended Attacks on ECDSA with Noisy Multiple Bit Nonce Leakages -- Single Trace Analysis of Comparison Operation based Constant-Time CDT Sampling and Its Countermeasure -- A Lattice Attack on CRYSTALS-Kyber with Correlation Power Analysis -- Side-Channel Analysis on Lattice-Based KEM using Multi-feature Recognition - The Case Study of Kyber -- Not optimal but efficient: a distinguisher based on the Kruskal-Wallis test -- Signature Schemes -- 1-out-of-n Oblivious Signatures: Security Revisited and a Generic Construction with an Efficient Communication Cost -- Compact Identity-based Signature and Puncturable Signature from SQISign -- High Weight Code-based Signature Scheme from QC-LDPC Codes.

This book constitutes the refereed proceedings of the 26th International Conference on Information Security and Cryptology on Information Security and Cryptology - ICISC 2023, held in Seoul, South Korea, during November 29-December 1, 2023 The 31 full papers included in this book were carefully reviewed and selected from 78 submissions. They were organized in topical sections as follows: Part I: cryptanalysis and quantum cryptanalysis; side channel attack; signature schemes. Part II: cyber security; applied cryptography; and korean post quantum cryptography.