**Preface**
This book contains papers based on lectures presented at the NATO Advanced Study Institute “Information Security and Related Combinatorics”, held in the beautiful town of Opatija at the Adriatic Coast of Croatia from May 31 to June 11, 2010. On behalf of all participants, we would like to thank the NATO Science for Peace and Security Programme for providing funds for the conference, as well as the local sponsors, which included the Ministry of Science and Education of the Republic of Croatia, the Croatian Academy of Sciences and Arts, the Primorsko-goranska County, the University of Rijeka and its Mathematics Department, the Foundation of the University of Rijeka, the Society of Mathematicians and Physicists, the Login Co., the Opatija Tourist Board, the City of Opatija, the City of Rijeka, and Brodokomerc.nova.

The Advanced Study Institute had fourteen lecturers: K.T. Arasu (USA), C. Colbourn (USA), F. Fuji-Hara (Japan). W. Haemers (The Netherlands), M. Jimbo (Japan), J.D. Key (USA), H. Kharaghani (Canada), C. Lam (Canada), S. Magliveras, (USA), J. Moori (South Africa), T. Shaska (USA), L. Storme (Belgium), V.D. Tonchev (USA), R. Wilson (USA), and was attended by over 60 graduate students and junior scientists from Albania, Armenia, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Germany, Italy, Macedonia, The Netherlands, Russia, Turkey, and USA.

The unifying theme of the conference was combinatorial mathematics used in applications related to information security, cryptography, and coding theory.

The book will be of interest to mathematicians, computer scientists and engineers working in the area of digital communications, as well as to researchers and graduate students who are willing to learn more about the applications of combinatorial mathematics to problems arising in communications and information security. The majority of papers are surveys on topics that are subject to current research and are written in a tutorial text book style that makes this volume a good source as an additional text for a course in discrete mathematics or applied combinatorics. The book can be used in graduate courses of applied combinatorics with a focus on coding theory and cryptography.

Dean Crnković and Vladimir Tonchev