Welcome

I am a Postdoctoral Research Fellow at the School of Mathematical Sciences, University College Dublin. My position is funded by the Science Foundation Ireland under the PI Grant on Public-Key Cryptography Based on Finite Simple Semirings.

Moreover, I am a member of the Claude Shannon Institute for Discrete Mathematics, Coding, Cryptography and Information Security. I am also associated with the recently established COST Action on Random Network Coding where I am a member of the Irish management committee.

Before joining the Claude Shannon Institute, I was a doctoral student at the University of Zurich and a member of the Applied Algebra group led by Joachim Rosenthal at the Mathematics Institute.

Current research interests: Discrete Logarithms, Function Field Sieve. Simple Semirings. Public-Key Cryptography using Semigroup Actions. Codes over Rings. Pseudocodewords. Black-box Algorithms for Groups.

Recent conferences

• WCC 2013 . Workshop on Coding and Cryptography . Bergen, 15-19 April 2013
• Trends in Coding Theory . Centro Stefano Franscini . Ascona, 28 Oct-2 Nov 2012
• ISIT 2012 . International Symposium on Information Theory . Boston, 1-6 July 2012
• Dagstuhl Seminar . Coding Theory . Wadern, 13-18 Nov 2011
• WCS 2011 . 6th Workshop on Coding and Systems . Aveiro, 11-13 June 2011
• WCC 2011 . Workshop on Coding and Cryptography . Paris, 11-15 April 2011
• ITW 2010 Dublin . IEEE Information Theory Workshop . Dublin, 30 Aug-3 Sep 2010
• MTNS 2010 . Mathematical Theory of Networks and Systems . Budapest, 5-9 July 2010
• Alcoma 10 . Algebraic Combinatorics and Applications . Thurnau, 11-18 Apr 2010
• WCS 2009 . 5th Workshop on Coding and Systems . Dublin, 2-4 Sep 2009
• 2nd Mile High Conference . Nonassociative Mathematics . Denver, 21-27 June 2009

Short vita

• since 2009: Postdoctoral Research Fellow, University College Dublin, Ireland
• 2004-2008: Assistant and doctoral student, University of Zurich, Switzerland
• 2002-2003: Certificate of Advanced Study in Mathematics (Part III), University of Cambridge, UK
• 1999-2004: Study of mathematics (Diplom) and computer science (Vordiplom), University of Oldenburg, Germany

Read the long version (pdf).

Publications

Journal articles

• Y. Katsov, T. G. Nam, J. Zumbrägel. On simpleness of semirings and complete semirings. Preprint, Submitted, 29 pages, 2011.  arXiv
• A. Kendziorra, J. Zumbrägel. Finite simple additively idempotent semirings. J. Algebra 388 (2013), pp. 43-64.  doi  arXiv
• A. Kendziorra, S. E. Schmidt, J. Zumbrägel. Invertible matrices over finite additively idempotent semirings. Semigroup Forum 86, no. 3 (2013), pp. 525-536.  doi  arXiv
• E. Byrne, M. Greferath, J. Pernas, J. Zumbrägel. Algebraic decoding of negacyclic codes over Z₄. Des. Codes Cryptogr. 66, no. 1-3 (2013), pp. 3-16.  doi  arXiv
• M. Greferath, C. Mc Fadden, J. Zumbrägel. Characteristics of invariant weights related to code equivalence over rings. Des. Codes Cryptogr. 66, no. 1-3 (2013), pp. 145-156.  doi  arXiv
• J. Zumbrägel, V. Skachek, M. F. Flanagan. On the pseudocodeword redundancy of binary linear codes. IEEE Trans. Inform. Theory 58, no. 7 (2012), pp. 4848-4861.  doi  arXiv
• J. Zumbrägel. Classification of finite congruence-simple semirings with zero. J. Algebra Appl. 7, no. 3 (2008), pp. 363-377.  doi  arXiv

Conference proceedings

• F. Göloğlu, R. Granger, G. McGuire, J. Zumbrägel. On the Function Field Sieve and the Impact of Higher Splitting Probabilities. Accepted for Advances in Cryptology−CRYPTO 2013, Santa Barbara, CA, USA, 14 pages.  eprint
• M. Greferath, J. Zumbrägel. On the algebraic representation of selected optimal non-linear binary codes. Proc. IEEE International Symposium on Information Theory (ISIT 2012), Cambridge, MA, USA, pp. 3115-3119.  doi  arXiv
• C. Mc Fadden, M. Greferath, J. Zumbrägel. Characteristics of invariant weights related to code equivalence over rings. Proc. 7th International Workshop on Coding and Cryptography (WCC 2011), Paris, France, pp. 91-99.
• E. Byrne, M. Greferath, J. Pernas, J. Zumbrägel. Algebraic decoding of negacyclic codes over Z₄. Proc. 7th International Workshop on Coding and Cryptography (WCC 2011), Paris, France, pp. 101-110.
• J. Zumbrägel, M. F. Flanagan, V. Skachek. Exploration of AWGNC and BSC pseudoredundancy. Proc. 19th International Symposium on Mathematical Theory of Networks and Systems (MTNS 2010), Budapest, Hungary, 7 pages.  arXiv
• J. Zumbrägel, M. F. Flanagan, V. Skachek. On the pseudocodeword redundancy. Proc. IEEE International Symposium on Information Theory (ISIT 2010), Austin, TX, USA, pp. 759-763.  doi  arXiv
• J. Zumbrägel, G. Maze, J. Rosenthal. Efficient recovering of operation tables of black box groups and rings. Proc. IEEE International Symposium on Information Theory (ISIT 2008), Toronto, ON, Canada, pp. 639-643.  doi  arXiv

Theses

• J. Zumbrägel. Public-key cryptography based on simple semirings. Ph.D. dissertation, Universität Zürich, Switzerland, December 2008.  pdf
• J. Zumbrägel. Modular-Theorie und die Konstruktion nicht-kommutativer L_p-Räume nach Haagerup. Diploma thesis, Universität Oldenburg, Germany, October 2004.  pdf
• J. Zumbrägel. Subharmonic methods in Banach algebra theory. Essay as part of the Part III Examination, University of Cambridge, UK, May 2003.  pdf

Teaching

At University College Dublin:

• Differential Equations via Computer Algebra - Fall term 2010
• Calculus II - Spring term 2009

At the University of Zurich I led seminars and exercise classes for the following lectures:

• Seminar Endliche Körper - Fall term 2008
• Coding Theory - Spring term 2008
• Algebra I - Fall term 2007
• Lineare Algebra II - Summer term 2007
• Lineare Algebra I - Winter term 2006/07
• Analysis II - Summer term 2006
• Analysis I - Winter term 2005/06
• Einführung in die Angewandte Mathematik - Summer term 2005

I was enrolled in the voluntary program Teaching Skills offered by the centre for academia didactics of the University of Zurich.

During my diploma studies in Oldenburg I was conducting exercise classes on linear algebra, analysis and stochastics.