Areas of Interest

• Cryptology, Cryptographic Boolean functions; Quantum Computing and Cryptography, Stream Cipher Cryptanalysis.

Professional Background

From	Period	Position	Organisation
2020-08-31	Ongoing	Professor	IIT Roorkee
2012-01-01	Ongoing	Associate Professor	IIT Roorkee
2012-01-01		Associate Professor	Indian Statistical Institute
2004-01-01	8 years	Assistant Professor	IIT Roorkee
2004-01-01		Assistant Professor	IIT Kharagpur
1999-01-01	4 years	Lecturer	BITS Pilani
1997-01-01	1 year	Visiting Fellow	HRI Allahabad

Multiple Posts

From	Period	Position	Organisation
2015-01-01	1 year	OC Examination CSE	IIT Roorkee
2016-01-01	2 years	OC Administration. CSE	IIT Roorkee
2017-01-01	Ongoing	OC Maintenance. CSE.	IIT Roorkee
2017-01-01	1 year	DAPC Chairman. CSE.	IIT Roorkee

Honors and Awards

Award	Institute	Year
Visiting Professorship (Erasmus+)	University of Primorska, Koper. Slovenia.	2017
Outstanding Teacher Award	Indian Institute of Technology Roorkee	2016
ONR-Global VSP award.	Naval Postgraduate School, Monterey, USA.	2013
Institute Silver Medal	Indian Institute of Technology Kharagpur	1993

Educational Details

Degree	Subject	University	Year
Ph.D.	Mathematics	Indian Institute of Technology Kharagpur	1998
M.Sc.	Mathematics	Indian Institute of Technology Kharagpur	1993

Sponsored Research Projects

Topic	Funding Agency	Start Date	Period
Unified approach for Cryptographic Boolean Functions (Inida-Belarus Collaborative Project)	DST	2017-01	Ongoing
Lightweight Encryption Techniques for Cyber Security Applications(India-Japan Collaborative Project)	DST - JSPS	2016-01	Ongoing
Crypto. Significant Boolean Func. with Appl. in Stream and Block Ciphers (Indo-Slovenian joint proj)	DST-MHE Slovenia	2011-01	9 years 7 months
Security evaluation and design of crypto primitives for RFID and Sensor Networks (India-Japan)	DST-JST	2009-01	11 years 7 months
Noncommutative and Nonassociative Structures in Information Theory (India-Russia joint project)	DST-RFBR	2015-01	Ongoing
Information Security Education and Awareness (ISEA) Project phase II	DeitY	2014-01	Ongoing

Visits to outside institutions

Institute Visited	Purpose of Visit	Date
University of York, UK	Collaborative research	2015-01-01
INRIA Paris	Invited Professor	2020-08-31
INRIA Paris	Invited Professor	2020-08-31
Naval Postgraduate School, Monterey, California, USA.	Visiting Professor	2020-08-31
Naval Postgraduate School, Monterey, California, USA.	Visiting Professor	2020-08-31
National Institute of Advanced Science and Technology, Tsukuba, Japan	Project work	2013-01-01
University of Primorska, Slovenia	Project work	2012-01-01
Nanyang Technological University, Singapore	Research collaboration	2012-01-01
University of Primorska, Slovenia	Project work	2020-08-31
National Institute of Advanced Industrial Science and Technology, Tokyo, Japan	Project work	2020-08-31
National Institute of Advanced Industrial Science and Technology, Tokyo, Japan	Project work	2011-01-01
National Institute of Advanced Industrial Science and Techlogy, Tokyo, Japan	Project work	2020-08-31
University of Lund, Sweden	Research collaboration	2003-01-01
Indian Statistical Institute Kolkata	Visiting Scientist	2003-01-01

Courses or Conferences Organised

Conference Name	Sponsored By	Date
India-Japan Workshop on Cryptographic Techniques for Cyber Security	Partly by DST-JSPS Project	2020-08

Referred Journal Papers

• A quantum algorithm to estimate the Gowers U_2 norm and linearity testing of Boolean functions, Jothishwaran C. A., Tkachenko A., Gangopadhyay S., Riera C., and Stanica P., Springer, 2020 , Quantum Information Processing , 19(9) vols

Particulars of course

- Developed NPTEL course entitled Discrete Mathematics. - Developed a four week lecture course entitled “Introduction to Cryptology” for NPTEL under the Massive Online Open Course (MOOC) program. (2016, total enrollment over 6000)

Refereed Journal Papers

1. Maitra S, Sinha S, Siddhanti A, Anand R and Gangopadhyay S, A TMDTO attack against Lizard. IEEE Transactions on Computers (accepted). 
2. Mandal B., Singh B.,  Gangopadhyay S., Maitra S and Vetrivel  V., On Non-existence of Bent-negabent Rotation Symmetric Boolean Functions, Discrete Applied Mathematics (accepted).
3. Gangopadhyay S., Paul G., Sinha S. and Stanica P., Generalized Nonlinearity of S-boxes, Advances in Mathematics of Communications. (accepted) 
4. Mandal, B., Gangopadhyay, S. and Stanica, P., Gowers U_3 norm of some classes of Boolean functions, Des. Codes Cryptogr. DOI10.1007/s10623-017-383-z.
5. Mandal, B., Gangopadhyay, S. and Stanica, P., Cubic Maiorana-McFarland bent functions with no affine derivatives, International Journal of Computer Mathematics: Computer Systems Theory, 2(1) 14-27.  DOI 10.1080/23799927.2017.1304453.
6. Gangopadhyay, S., Pasalic, E., Stanica, P. and Datta, A note on non-splitting -bent functions, Information Processing Letters 121(2017) 1 - 5.
7. Pasalic, E., Muratovic-Ribic, A., Hodzic, S. and Gangopadhyay, S.,  On derivatives of polynomials over finite fields through integration, Discrete Applied Mathematics, 217(2017) 294 - 303.
8. Gangopadhyay, S., Kar Gangopadhyay, A.,Pollatos, S. and Stanica, P., Cryptographic Boolean functions with biased inputs, Cryptography and Communications – Discrete Structures, Boolean functions and Sequences 9(2): 301-314(2017)
9. Gangopadhyay, S., Singh, B. and Vetrivel, V., Investigations on cubic rotation symmetric bent functions, Electronic Notes in Discrete Mathematics 56(2016) 15 - 19.
10. Mandal, B., Stanica, P., Gangopadhyay, S., Pasalic, E., An Analysis of  Class of Bent Functions, Fundamenta Informaticae, 146(3) (2016) 271 - 292.
11. Gangopadhyay, S., and Mandal, B., Second-Order Nonlinearity Bounds of Cubic MMF Bent-Negabent Functions Constructed by Using Feistel Functions, in special issue for “Cryptology and Cyber-Security”, the IPSI BgD Transactions on Advanced Research, vol. 11, no. 1, 13 – 19 (2015).
12. Gangopadhyay, S., and Sharma, D., A Note on the Structure of 6-Variable Bent Functions, inspecial issue for “Cryptology and Cyber-Security”, the IPSI BgDTransactions on Advanced Researchvol. 11, no. 1, 20 – 24 (2015)
13. Bajric, S., Pasalic, E., Ribic-Muratovic, A. and Gangopadhyay, S., On generalized bent functions with Dillon’s exponents, Information Proc. Letters, 114: 222 – 227 (2014).
14. Artamonov, V. A., Chakrabarti, S. Gangopadhyay, S and Pal, S. K., On Latin squares of polynomially complete quasigroups generated by shifts, Quasigroups and related systems 21: 117 – 130 (2013).
15. Gangopadhyay, S., Pasalic, E. and Stanica, P., A note on generalized bent criteria for Boolean functions, IEEE Trans. Inform. Theory 59(5):3233 – 3236  (2013).
16. Gangopadhyay, S., Affine inequivalence of cubic Maiorana--McFarland type bent functions, Discrete Applied Mathematics 161(7-8): 1141–1146 (2013).
17. Gangopadhyay S., Joshi A., Leander G. and Sharma R. K., A new construction of bent functions based on -bent functions, Des. Codes Cryptogr. 66(1-3): 243 – 256 (2013).
18. Stanica P, Martinsen T., Gangopadhyay S. and Singh B. K.,Bent and generalized bent Boolean functions,Des. Codes Cryptogr. 69(1):77 – 94(2013).
19. Mihaljevic M., Gangopadhyay S., Paul G. and Imai H.,Internal State Recovery of Keystream Generator LILI-128 Based on aNovel Weakness of the Employed Boolean Function Information Processing Letters, 112(21):805 – 810 (2012).
20. Mihaljevic M., Gangopadhyay S., Paul G. and Imai H., Generic Cryptographic Weakness ofk-normal Boolean Functions in Certain Stream Ciphersand Cryptanalysis of Grain-128, Periodica Mathematica  Hungarica 65(2):39 – 61 (2012).
21. Stanica P., Gangopadhyay S., Chaturvedi A., Kar Gangopadhyay A. and MaitraS., Investigations on bent and negabent functions via the nega-Hadamard transform, IEEE Trans. Inform. Theory 58(6):4064 – 4072 (2012).
22. Gangopadhyay S. and Singh B. K.,On second-order nonlinearities of some  type bent functions, Fundamenta Informaticae 114(3 – 4):271 – 285 (2012).
23. Mihaljevic M., Gangopadhyay S., Paul G. and Imai H., Internal State Recovery of Grain-v1 Employing Normality Order of the Filter Function, IET Information Security 6(2): 55 – 64 (2012).
24. Garg M. and Gangopadhyay S., A lower bound of the second-order nonlinearities of Boolean bent functions, Fundamenta Informaticae 111(4): 413 – 422 (2011).
25. Gode R. and Gangopadhyay S., On lower bounds of second-order nonlinearities of cubic bent functions constructed by concatenating Gold functions, International Journal of Computer Mathematics 88(15):3125 – 3135 (2011).
26. Canright D., Gangopadhyay S., Maitra S. and Stanica P., Laced Boolean functions and subset sum problem in finite fields, Discrete Applied Mathematics 159 (11): 1059 – 1188 (2011).
27. Gode R. and Gangopadhyay S., Third-order nonlinearities of a subclass of Kasami functions, Cryptography and Communications - Discrete Structures, Boolean Functions and Sequences2: 69 – 83 (2010).
28. Gode R. and Gangopadhyay S., On higher-order nonlinearities of monomial partial spreads type Boolean functions, Journal of Combinatorics, Information and System Sciences 35(3 – 4): 341 – 360 (2010).
29. Gangopadhyay S., Sarkar S. and Telang R., On the lower bounds of second order nonlinearities of some Boolean functions, Information Sciences 180: 266--273 (2010).
30. Gangopadhyay S., Sharma D., Sarkar S., MaitraS.,On Affine (Non) Equivalence of Bent Functions, Computing85: 37 – 55 (2009).
31. Maitra S., Subba Rao Y. V., Stanica P., GangopadhyayS., Non trivial solutions to cubic seive congruence problems: x^3 = y^2 mod p, Special Issue on Applied Cryptography \& Data Security, Journal of “Computacion y Sistemas”, 12(3): 253 – 266 (2009).
32. Gangopadhyay S., Sharma D.,On construction of non-normal Boolean functions,Australasian journal of combinatorics38: 267 – 272 (2007).
33. Gangopadhyay S., Keskar P. H., MaitraS.,Patterson - Wiedemann construction revisited, Discrete MathematicsVol. 306, Issue 14, pp. 1540 – 1556, 2006.
34. Sharma R. K., GangopadhyayS.,On congruence subgroups and units in ZS_4 ,Communications in Algebra 32(2): 663 – 668 (2004).
35. Gangopadhyay S., A note on character sums with polynomial arguments,Finite Fields and Their Applications 9(4): 449 – 457 (2003).
36. Sharma R. K., Gangopadhyay S., On Units in  ZD_4, Pan American MathematicalJournal 2(1): 1 – 9 (2001).
37. Sharma R. K., Gangopadhyay S., On Chains in Units of ZA_4 , Mathematical Sciences Research Hotline 4(9): 1 – 33 (2000).
38. Sharma R. K., Gangopadhyay S., On Units in ZA_4, Mathematical Sciences Research Hotline 4(8): 13 – 29 (2000).
39. Sharma R. K., Gangopadhyay S., V. Vetrivel, On Units in ZS_3 Communications in Algebra 25(7): 2285 – 2299 (1997).