This book constitutes the refereed proceedings of the 9th International Conference on Cryptology and Information Security in Latin America, LATINCRYPT 2025, held in Medellín, Colombia, in October 2025.The 17 full papers included in this book were carefully reviewed and selected from 41 submissions.They were focused on the following topical sections: Position Paper; Zero-Knowledge Proofs and Distributed Computation; Quantum and Post-Quantum Cryptography; Symmetric-Key Cryptography and Attacks; Machine Learning and Cryptanalysis; and Implementation and Efficiency.

In July 1998, a summer school in cryptology and data security was organized atthecomputersciencedepartmentofAarhusUniversity,Denmark.Thistook place as a part of a series of summer schools organized by the European Edu- tional Forum, an organizationconsisting of the researchcenters TUCS (Finland), IPA(Holland)andBRICS(Denmark,Aarhus).Thelocalorganizingcommittee consisted of Jan Camenisch, Janne Christensen, Ivan Damga? ard (chair), Karen Moller,andLouisSalvail.ThesummerschoolwassupportedbytheEuropean Union. Modern cryptology is an extremely fast growing ?eld and is of fundamental importance in very diverse areas, from theoretical complexity theory to practical electroniccommerceontheInternet.Wethereforesetouttoorganizeaschool that would enable young researchers and students to obtain an overview of some mainareas,coveringboththeoreticalandpracticaltopics.Itisfairtosaythat the school was a success, both in terms of attendance (136 participants from over20countries)andintermsofcontents.Itisapleasuretothankallofthe speakers for their cooperation and the high quality of their presentations.A total of 13 speakers gave talks: Mihir Bellare, University of California, San Diego; Gilles Brassard, University of Montreal; David Chaum, DigiCash; Ronald Cramer, ETH Zur .. ich; Ivan Damg? ard, BRICS; Burt Kaliski, RSA Inc.; Lars Knudsen, Bergen University; Peter Landrock, Cryptomathic; Kevin Mc- Curley, IBM Research, Almaden; Torben Pedersen, Cryptomathic; Bart Preneel, Leuven University; Louis Salvail, BRICS; Stefan Wolf, ETH Zur .. ich.

This book constitutes the refereed proceedings of the 9th International Conference on Cryptology and Information Security in Latin America, LATINCRYPT 2025, held in Medellín, Colombia, in October 2025.The 17 full papers included in this book were carefully reviewed and selected from 41 submissions.They were focused on the following topical sections: Position Paper; Zero-Knowledge Proofs and Distributed Computation; Quantum and Post-Quantum Cryptography; Symmetric-Key Cryptography and Attacks; Machine Learning and Cryptanalysis; and Implementation and Efficiency.

In July 1998, a summer school in cryptology and data security was organized atthecomputersciencedepartmentofAarhusUniversity,Denmark.Thistook place as a part of a series of summer schools organized by the European Edu- tional Forum, an organizationconsisting of the researchcenters TUCS (Finland), IPA(Holland)andBRICS(Denmark,Aarhus).Thelocalorganizingcommittee consisted of Jan Camenisch, Janne Christensen, Ivan Damga? ard (chair), Karen Moller,andLouisSalvail.ThesummerschoolwassupportedbytheEuropean Union. Modern cryptology is an extremely fast growing ?eld and is of fundamental importance in very diverse areas, from theoretical complexity theory to practical electroniccommerceontheInternet.Wethereforesetouttoorganizeaschool that would enable young researchers and students to obtain an overview of some mainareas,coveringboththeoreticalandpracticaltopics.Itisfairtosaythat the school was a success, both in terms of attendance (136 participants from over20countries)andintermsofcontents.Itisapleasuretothankallofthe speakers for their cooperation and the high quality of their presentations.A total of 13 speakers gave talks: Mihir Bellare, University of California, San Diego; Gilles Brassard, University of Montreal; David Chaum, DigiCash; Ronald Cramer, ETH Zur .. ich; Ivan Damg? ard, BRICS; Burt Kaliski, RSA Inc.; Lars Knudsen, Bergen University; Peter Landrock, Cryptomathic; Kevin Mc- Curley, IBM Research, Almaden; Torben Pedersen, Cryptomathic; Bart Preneel, Leuven University; Louis Salvail, BRICS; Stefan Wolf, ETH Zur .. ich.