Dr. Tamir Tassa

• Contact Information
• Education
• Fields of Research
• Positions
• Publications
• Program Committees
• Travel Stories

CONTACT INFORMATION

Tel: +972-9-7781272, +972-52-3646540

Fax: +972-9-7780605

E-mail: tamirta [strudel] openu [dot] ac [dot] il

EDUCATION

1993	Ph.D., Department of Applied Mathematics, School of Mathematical Sciences, Tel Aviv University. One-sided Lipschitz stability and its applications for nonlinear conservation laws. Advisor: Professor Eitan Tadmor
1987	M.Sc. (summa cum laude), Department of Applied Mathematics, School of Mathematical Sciences, Tel Aviv University. Thesis: Applications of compensated compactness to scalar hyperbolic conservation laws. Advisor: Professor Eitan Tadmor
1984	B.Sc. in Computer Science and Mathematics (summa cum laude), School of Mathematical Sciences, Tel Aviv University.

FIELDS OF RESEARCH

• Privacy-preserving data mining and publishing, anonymization of databases and social networks.
• Cryptology - secret sharing, data security in broadcasting networks (broadcast encryption, traitor tracing, watermarking), multi-party computation.
• Combinatorial optimization - polynomial time approximation schemes, scheduling and assignment problems, mathematical programming.
• Mathematical analysis - hyperbolic conservation laws and degenerate parabolic equations, finite difference and spectral method approximations, homogenization.

ACADEMIC POSITIONS

2007-2009	Chair, Department of computer science, The Open University.
2003-present	Senior lecturer, Department of computer science, The Open University.
2003-2004	Lecturer, Department of computer science, Ben Gurion University.
2002-2003	Lecturer and researcher, School of Mathematical Sciences, Tel Aviv University.
2000-present	Lecturer, Faculty of computer science, Interdisciplinary Center, Herzelia.
1999-2003	Lecturer, Academic College of Tel-Aviv.
1996-1997	Lecturer and researcher, School of Mathematical Sciences, Tel Aviv University.
1993-1996	Assistant Professor of Computational and Applied Mathematics, Department of Mathematics, UCLA
1994, summer	Visiting Professor, Department of Mathematics, University of Metz.
1987-1993	Instructor, School of Mathematical Sciences, Tel Aviv University.
1989, fall	Graduate Fellow, Institute for Computer Applications in Science and Engineering (ICASE), NASA Langley Research Center, Hampton, Virginia

OTHER POSITIONS

9/2002-3/2003	Lead Scientist – Maya Software Technologies Ltd. Conducted research in the areas of elliptic and hyperelliptic curve based cryptography.
12/2000-11/2001	Senior Algorithm Engineer – Bigband Networks Ltd. Developed algorithms for video processing, transmission, quality evaluation and broadcast management.
4/1999-10/2000	Chief Technical Officer – Algorithmic Research Ltd. Responsibilities included: evaluating new data security technologies for decision making regarding future company activity; scientific and technical supervision and assistance in current company activity; managing intellectual property issues; managing standardization issues.
1/1997-3/1999	Chief Scientist – Orcast (a subsidiary of Cylink Ltd.) The company produced conditional access solutions as well as other components and applications for digital Pay TV systems.

PUBLICATIONS

Journal Papers

• E. Tadmor and T. Tassa On the piecewise smoothness of entropy solutions to scalar conservation laws, Communications in Partial Diffe rential Equations, Vol. 18 (1993), pp. 1631-1652. 
• H. Nessyahu, E. Tadmor and T.Tassa, The convergence rate of Godunov type schemes, Siam Journal on Numerical Analysis, Vol. 31 (1994), pp. 1-16. 
• H. Nessyahu and T. Tassa, Convergence rate of approximate solutions to conservation laws with initial rarefactions, Siam Journal on Numerical Analysis, Vol. 31 (1994), pp. 628-654. 
• T. Tassa, Regularity of weak solutions of the nonlinear Fokker-Planck equation, Mathematical Research Letters, Vol. 3 (1996), pp. 475-490. 
• E. Tadmor and T. Tassa, On the homogenization of oscillatory solutions to nonlinear convection-diffusion equations, Advances in Mathematical Sciences and Applications, Vol. 7 (1997), pp. 93-117.
• T. Tassa, Uniqueness of piecewise smooth weak solutions of multidimensional degenerate parabolic equations, Journal of Mathematical Analysis and Applications, Vol. 210 (1997), pp. 598-608.
• T. Tassa, Homogenization of two-dimensional linear flows with integral invariance, Siam Journal on Applied Mathematics, Vol. 57 (1997), pp. 1390-1405. 
• T. Tassa, On the homogenization of nonlinear convection-diffusion equations with oscillatory initial and forcing data. Mathematical Sciences and Applications, Vol. 10 (1997), Nonlinear Waves, pp. 493-501.
• T. Tassa, Homogenization with multiple scales, Asymptotic Analysis, Vol. 20 (1999), pp. 61-96.
• A. Fiat and T. Tassa, Dynamic traitor tracing, Journal of Cryptology, Vol. 14 (2001), pp. 211-223.
• T. Tassa, On finite closures of homogenized solutions of nonlinear hyperbolic equations, Asymptotic Analysis, Vol. 34 (2003), pp. 55-76.
• L. Epstein and T. Tassa, Vector assignment problems: a general framework, Journal of Algorithms, Vol. 48 (2003), pp. 360-384.
• L. Epstein and T. Tassa, Approximation schemes for the min-max starting time problem, Acta Informatica, Vol. 40 (2004), pp. 657-674.
• T. Tassa, Low bandwidth dynamic traitor tracing schemes, Journal of Cryptology, Vol. 18 (2005), pp. 167-183.
• L. Epstein and T. Tassa, Optimal preemptive scheduling for general target functions, Journal of Computer and System Sciences, Vol. 72 (2006), pp. 132-162.
• L. Epstein and T. Tassa, Vector assignment schemes in asymmetric settings, Acta Informatica, Vol. 42 (2006), pp. 501-514.
• N. Kogan and T. Tassa, Improved efficiency for revocation schemes via Newton interpolation, ACM Transactions on Information and System Security, Vol. 9 (2006), pp. 461-486.
• T. Tassa, A linear algebraic approach in teaching interpolation, Mathematics And Computer Education (2007), pp. 37-45.
• T. Tassa, Hierarchical threshold secret sharing, Journal of Cryptology, Vol. 20 (2007), pp. 237-264. 
• J. Goldberger and T. Tassa, A hierarchical clustering algorithm based on the Hungarian method, Pattern Recognition Letters, Vol. 29 (2008), pp. 1632–1638.
• A. Beimel, T. Tassa and E. Weinreb, Characterizing ideal weighted threshold secret sharing, SIAM Journal on Discrete Mathematics, Vol. 22 (2008), pp. 360-397.
• O. Blayer and T. Tassa, Improved versions of Tardos' fingerprinting scheme, Designs, Codes and Cryptography, Vol. 48 (2008), pp. 79-103.
• T. Tassa and J.L. Villar, On proper secrets, (t,k)-bases and linear codes. Designs, Codes and Cryptography, Vol. 52 (2009), pp. 129-154. 
• T. Tassa and N. Dyn, Multipartite secret sharing by bivariate interpolation. Journal of Cryptology, Vol. 22 (2009), pp. 227-258. 
• A. Gionis and T. Tassa, k-Anonymization with minimal loss of information. IEEE Transactions on Knowledge and Data Engineering, Vol. 21 (2009), pp. 206-219.
• J. Goldberger and T. Tassa, Efficient Anonymizations with Enhanced Utility. Transactions on Data Privacy, Vol. 3 (2010), pp. 149-175.
• D. Berend and T. Tassa, Improved bounds on Bell numbers and on moments of sums of random variables. Probability and Mathematical Statistics, Vol. 30 (2010), pp. 185-205.
• T. Tassa, Generalized Oblivious Transfer by Secret Sharing. Designs, Codes and Cryptography, Vol. 58 (2011), pp. 11-21.
• B. Kenig and T. Tassa, A Practical Approximation Algorithm for Optimal k-Anonymity. Data Mining and Knowledge Discovery, Vol. 25 (2012), pp. 134-168. 
• T. Tassa and D. Cohen, Anonymization of Centralized and Distributed Social Networks by Sequential Clustering. To appear in Transactions on Knowledge and Data Engineering.
• T. Tassa and E. Gudes, Secure distributed computation of anonymized views of shared databases.  Transactions on Database Systems, Vol. 37 (2012), Article 11.
• T. Tassa, Finding all maximally-matchable edges in a bipartite graph. Theoretical Computer Science, Vol. 423 (2012), pp. 50-58.
• E. Shmueli, T. Tassa, R. Wasserstein, B. Shapira and L. Rokach, Limiting disclosure of sensitive data in sequential releases of databases. Information Sciences, Vol. 191 (2012), pp. 98-127.
• T. Tassa, A. Mazza and A. Gionis, k-Concealment: An alternative model of k-type anonymity. Transactions on Data Privacy, Vol. 5 (2012), pp. 189-222.
• P. Boldi, F. Bonchi, A. Gionis and T. Tassa, Injecting uncertainty in graphs for identity obfuscation. Proceedings of the Very Large Databases Endowment (PVLDB) (2012).

Conferences

• T. Tassa, On the homogenization of nonlinear convection-diffusion equations with oscillatory initial and forcing data,  Proceedings of the 4th MSJ International Research Institute on "Nonlinear Waves", July 1995, Sapporo, pp. 478-486.
• A. Fiat and T. Tassa, Dynamic traitor tracings, Proceedings of Crypto 99, August 1999, Santa Barbara,pp. 354-371.
• L. Epstein and T. Tassa, Vector assignment problems: a general framework, Proceedings of the European Symposium on Algorithms (ESA), September 2002, Rome, pp. 461-472.
• L. Epstein and T. Tassa, Approximation schemes for the min-max starting time problem, Proceedings of the International Symposium on Mathematical Foundations of Computer Science (MFCS), August 2003, Bratislava, pp. 408-418.
• T. Tassa, Hierarchical threshold secret sharing, Proceedings of the Theory of Cryptography Conference (TCC), February 2004, MIT, Cambridge, pp. 473-490.
• L. Epstein and T. Tassa, Optimal preemptive scheduling for general target functions, Proceedings of the International Symposium on Mathematical Foundations of Computer Science (MFCS), August 2004, Prague, pp. 562-573.
• A. Beimel, T. Tassa and E. Weinreb, Characterizing ideal weighted threshold secret sharing, Proceedings of the Theory of Cryptography Conference (TCC), February 2005, MIT, Cambridge, pp. 600-619.
• A. Jaffe, M. Naaman, T. Tassa and M. Davis, Generating summaries for large collections of geo-referenced photographs (Poster), Proceedings of the International World Wide Web Conference (WWW), May  2006, Edinburgh, pp. 853-854.
• T. Tassa and N. Dyn, Multipartite secret sharing by bivariate interpolation, Proceedings of the International Colloquium on Automata, Languages and Programming (ICALP), Part II, July 2006, Venice, pp. 288-299.
• A. Jaffe, M. Naaman, T. Tassa and M. Davis, Generating summaries and visualization for large collections of geo-referenced photographs, ACM Multimedia Workshop On Multimedia Information Retrieval, October 2006, Santa Barbara, pp. 89-98.
• A. Gionis and T. Tassa, k-Anonymization with minimal loss of information. Proceedings of the European Symposium on Algorithms (ESA), October 2007, Eilat, pp. 439-450.
• A. Gionis, A. Mazza and T. Tassa, k-Anonymization revisited, Proceedings of the International Conference on Data Engineering (ICDE), April 2008, Cancun, pp. 744-753.
• J. Goldberger and T. Tassa, Efficient Anonymizations with Enhanced Utility, ICDM Workshop on Privacy Aspects of Data Mining, December 2009, Miami, pp. 106-113.
• F. Bonchi, A. Gionis and T. Tassa, Identity obfuscation in graphs through the information theoretic lens. Proceedings of the International Conference on Data Engineering (ICDE), April 2011, Hannover, pp. 924-935.

Manuscripts

• X. Liu, E. Tadmor and T. Tassa, A uniformly third order accurate scheme for genuinely nonlinear scalar conservation laws.

Patents

• T. Tassa (Inventor), Bigband Networks Ltd. (Assignee), Method for allocating media unit sequences among a plurality of output channels, US patent 6914936.
• R. Oz and T. Tassa (Inventors), Bigband Networks Ltd. (Assignee), Method and Systems for providing enhanced television services, US patent 7787439.

Articles in Hebrew

Editorial Boards and Program Committees

• Journal of Discrete Mathematics
• LATIN 2008 (The 8^th Latin American Theoretical Informatics)
• SAC 2010  (Selected Areas in Cryptography)
• ECML PKDD 2010 (European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases)
• ICITS 2011 (The 5th International Conference on Information Theoretic Security)
• PAKDD 2011 (The 15th Pacific-Asia Conference on Knowledge Discovery and Data Mining)
• PAKDD 2012 (The 16th Pacific-Asia Conference on Knowledge Discovery and Data Mining)