Alain Poli - Böcker

Thisvolumerepresentstherefereedproceedingsofthe7thInternationalC- ference on Finite Fields and Applications (F 7) held during May 5-9, q 2003, in Toulouse, France. The conference was hosted by the Pierre Baudis C- gress Center, downtown, and held at the excellent conference facility. This event continued a series of biennial international conferences on Finite Fields and - plications, following earlier meetings at the University of Nevada at Las Vegas (USA) in August 1991 and August 1993, the University of Glasgow (UK) in July 1995, the University of Waterloo (Canada) in August 1997, the Univ- sity of Augsburg (Germany) in August 1999, and the Universidad Aut' onoma Metropolitana-Iztapalapa, in Oaxaca (Mexico) in 2001. The Organizing Committee of F 7 consisted of Claude Carlet (INRIA, Paris, q France), Dieter Jungnickel (University of Augsburg, Germany), Gary Mullen (Pennsylvania State University, USA), Harald Niederreiter (National University of Singapore, Singapore), Alain Poli, Chair (Paul Sabatier University, Toulouse, France), Henning Stichtenoth (Essen University, Germany), and Horacio Tapia- Recillas (Universidad Aut' onoma Metropolitan-Iztapalapa, Mexico).The program of the conference consisted of four full days and one half day of sessions, with eight invited plenary talks, and close to 60 contributed talks.

The 25 revised full papers presented here together with 7 invited papers address subjects such as block codes; algebra and codes: rings, fields, and AG codes; cryptography; sequences; decoding algorithms; and algebra: constructions in algebra, Galois groups, differential algebra, and polynomials.

TheAAECCsymposiumwasstartedinJune1983byAlainPoli(Toulouse),who, together with Roger Desq, Daniel Lazard, and Paul Camion, organized the ?rst conference. The meaning of the acronym AAECC changed from "Applied - gebra and Error Correcting Codes" to "Applied Algebra, Algebraic Algorithms, and Error Correcting Codes." One reason for this was the increasing importance of complexity, particularly for decoding algorithms. During the AAECC-12 s- posium the conference committee decided to enforce the theory and practice of the coding side as well as the cryptographic aspects. Algebra was conserved, as in the past, but was slightly more oriented to algebraic geometry codes, ?nite ?elds, complexity, polynomials, and graphs. For AAECC-15 the main subjects covered were: - Block codes. - Algebra and codes: rings, ?elds, AG codes. - Cryptography. - Sequences. - Algorithms, decoding algorithms. - Algebra: constructions in algebra, Galois groups, di?erential algebra, po- nomials. The talks of the six invited speakers characterized the aims of AAECC-15: - P. Sole ("Public Key Cryptosystems Based on Rings"). - S. Lin ("Combinatorics Low Density Parity Check Codes"). - J.Stern ("Cryptography and the Methodology of Provable Security"). - D. Costello ("Graph-Based Convolutional LDPC Codes"). - I. Shparlinsky ("Dynamical Systems Generated by Rational Functions"). - A. Lauder ("Algorithms for Multivariate Polynomials over Finite Fields").

The present volume contains the proceedings of the AAECC-5 Conference held at Menorca (Balearic Islands), June 15-19, 1987. The annual International AAECC Conference covers a range of topics related to Applied Algebra, Error-Correcting Codes, Finite Algebraic Structures, Computational Methods and Complexity in Algebra and Geometry. For the AAECC-5 Conference 73 papers were presented. Out of these thirty papers were selected for publication in the proceedings. They deal with topics such as error correcting codes (concerning problems of covering radius, decoding methods, expert systems and general results in coding theory), computational algebra, Grobner basis, complexity, finite algebra and graphs. The proceedings of the 6th conference are published as Vol. 357 of the Lecture Notes in Computer Science.