Last updated: August 24, 2017 at 19:14 pm

### Gérard Cohen

Due to unforeseen circumstances the talk is unfortunately cancelled

- Generalized distances and noises
- Restricted distances and angles
- Packings by coverings
- Coverings by packings
- Duality packings/coverings
- Duality coding/additive set theory.

We shall consider different level of complexity: constructive, semi-constructive (greedy algorithm, derandomization) and existential.

We present applications of these topics to traitor-tracing, broadcast encryption, hashing, writing on restricted memories, secret-sharing schemes, etc.

Gérard Cohen received the Engineer’s degree from Ecole Nationale Superieure des Telecommunications (ENST) in 1973 and Doctorat d’Etat es Sciences in Mathematics in 1980 from University Paris 6. He is currently Professor at ENST and has taught at various Universities, including Ecole Normale Superieure de Paris (Ulm), Paris 6 and supervised a dozen of PhD students. His main fields of interest are the coding theory, combinatorics, information theory and cryptography. Gérard Cohen has written over 150 papers in international Journals and co-authored 3 books. He is an IEEE Fellow, chairman and founder of the IEEE French Chapter in Information theory in 1993, and has been associate editor of the IEEE Transactions in Information theory from 2009 to 2012.

### Tor Helleseth

The cross correlation of m-sequences has been an important and challenging problem since 1968 when Robert Gold published his paper

*Maximal Recursive Sequences with 3-Valued Recursive Cross-Correlation Functions*. This paper formed the basis for the construction of the family of Gold sequences that has had many important applications in modern communications systems.

The cross correlation problem has since then been a subject for intensive research and has important connections to related problems in coding theory, cryptography, and mathematics. This problem has influenced several areas such as weight distribution of cyclic codes, difference sets, construction of sequences with two-level autocorrelation, permutation polynomials, Boolean functions, almost perfect nonlinear (APN) functions and bent functions.

This talk will present the history of the cross correlation of m-sequences and related problems during the last 50 years as well as an overview of recent results and some of the remaining unsolved open problems in this area.

Tor Helleseth received his Dr. Philos. degree in mathematics from the University of Bergen, Norway, in 1979. In 1979–1980 he was a Research fellow at the Eindhoven University of Technology, The Netherlands. From 1981 to 1984 he was at the Chief Headquarters of Defense in Norway. Since 1984 he has been a Professor at the Department of Informatics at the University of Bergen. His research interests are the coding theory, sequences, cryptography, and discrete mathematics. During 1991–1993 and 2012–2014 he served as an associate editor for the

*IEEE Transactions on Information Theory*. He is on the editorial board for several journals including

*Designs, Codes and Cryptography*;

*Cryptography and Communications: Discrete Structures, Boolean Functions and Sequences*. He was the program chair for many conferences including Eurocrypt’93, ITW1997, ITW2007, SETA (several times). In 2007-2009 he served on the Board of Governors for the IEEE Information Theory Society. He is an

*IEEE Fellow*and a member of

*Det Norske Videnskaps-Akademi*.

### Camilla Hollanti

The tutorial is based on joint work with Salim El Rouayheb, Ragnar Freij-Hollanti, Oliver Gnilke, David Karpuk, and Razan Tajeddine.

For 2004-2011 Hollanti was with the University of Turku. Since Oct. 2011, she has been with the Department of Mathematics and Systems Analysis at Aalto University, where she currently works as Associate Professor and leads a research group in Algebra, Number Theory, and Applications.

Hollanti is an editor of the AIMS Journal on Advances in Mathematics of Communications. She is a coauthor of 80 scientific peer-reviewed publications and a recipient of several grants, including five Academy of Finland grants in 2010-2016. In 2014, she received the World Cultural Council Special Recognition Award for young researchers.

### Raquel Pinto

Convolutional codes over \(Z_{p^r}\) behave very different from convolutional codes over finite fields, mainly due to the existence of zero divisors. In this talk, we will present an overview of the existing results in this area. In particular, we will focus on their distance properties, namely the free distance and the column distance and we will present constructions of codes with optimal free and column distances. We will also consider the dual of these codes and we will present an explicit construction of parity-check matrices with the purpose of their use on the decoding over the erasure channel.

In 1995, she joined the University of Aveiro, as a Teaching Assistant in the Department of Mathematics. Since 2003, she has been an Assistant Professor in the Department of Mathematics at the University of Aveiro. Her research interests are in the field of coding theory, with particular interest on convolutional coding, in the behavioural approach to systems theory, and the connections between systems theory and error control coding.

### Paul Siegel

A shaping code design strategy incorporating data compression and Varn coding is described, concluding with experimental results on a multilevel flash memory that demonstrate the potential benefit of this coding technique.

This is joint work with Yi Liu and Pengfei Huang.

His research focuses on information theory and coding, with applications to data storage and transmission. He was a Member of the Board of Governors of the IEEE Information Theory Society from 1991 to 1996 and from 2009 to 2014. He served as a co-guest editor of the 1991 Special Issue on Coding for Storage Devices of the IEEE Transactions on Information Theory and served the same Transactions as an associate editor from 1992 to 1995 and as Editor-in-Chief from 2001 to 2004. He has also been a co-guest editor of special issues of the IEEE Journal on Selected Areas in Communications. He received the 1992 IEEE Information Theory Society Paper Award and was the Society’s 2015 Padovani Lecturer. He also received the 1993 Leonard G. Abraham Prize and the 2007 Best Paper Award in Signal Processing and Coding for Data Storage from the IEEE Communications Society. He is an IEEE Fellow and a member of the U.S. National Academy of Engineering.