Serge Fehr
 Full Name
 Prof.dr. S. Fehr
 Function(s)
 Professor  Universiteit Leiden, Scientific Staff Member
 Serge.Fehr@cwi.nl
 Telephone
 +31 20 592 4257
 Room
 M259
 Department(s)
 Cryptology
 Homepage
 https://www.cwi.nl/~fehr/
Biography
Scientific staff member of the Cryptology Group at CWI, the Dutch Center for Mathematics and Computer Science in Amsterdam. Management committee member of the EU CryptoAction: Cryptography for Secure Digital Interaction, and member of QuSoft, the Dutch research center for quantum software. Supported by NWO, Netherlands Organisation for Scientific Research, and by DIAMANT, the Dutch national mathematics research network on Discrete, Interactive & Algorithmic Mathematics, Algebra & Number Theory.Research
Serge's primary field of interest is the mathematics of information security and cryptology, covering theoretical foundations as well as practical aspects. One main motivation is bringing theory and practice closer together by developing efficient systems whose security lies on firm theoretical ground. For example, one area of central interest is the feasibility of obtaining secure protocols in a partly dishonest multiplayer environment, as well as their algebraic and number theoretic aspects. Some keywords in this context are (verifiable) secret sharing, threshold cryptography, and multiparty computation. Another area of interest is informationtheoretic cryptography and quantum cryptography, i.e., the study of unconditionallysecure implementations of various cryptographic tasks, based on physical assumptions like a noisy channel or a quantum channel, again with a focus on practical yet provablysecure solutions. Furthermore, Serge is interested in and working on various other topics, like publickey encryption and zeroknowledge proofs. You are welcome to browse his list of publications.
Publications

Attema, T, Cramer, R.J.F, & Fehr, S. (2021). Compressing proofs of koutofn partial knowledge. In Advances in Cryptology (pp. 65–89). doi:10.1007/9783030842598_3

Chung, K.M, Fehr, S, Huang, Y.H, & Liao, T.N. (2021). On the compressedoracle technique, and postquantum security of proofs of sequential work. In Proceedings of EUROCRYPT 2021 (pp. 598–629). doi:10.1007/9783030778866_21

Fehr, S, & Yuan, C. (2020). Robust secret sharing with almost optimal share size and security against rushing adversaries. In TCC 2020: Theory of Cryptography (pp. 470–498). doi:10.1007/9783030643812_17

Fehr, S, & Vaudenay, S. (2020). Sublinear bounds on the distinguishing advantage for multiple samples. In Advances in Information and Computer Security (pp. 165–183). doi:10.1007/9783030582081_10

Don, J.W, Fehr, S, & Majenz, C. (2020). The measureandreprogram technique 2.0: Multiround FiatShamir and more. In CRYPTO 2020: Advances in Cryptology (pp. 602–631). doi:10.1007/9783030568771_21

de Boer, K, Ducas, L, & Fehr, S. (2020). On the Quantum Complexity of the Continuous Hidden Subgroup Problem. In Lecture Notes in Computer Science/Lecture Notes in Artificial Intelligence. doi:10.1007/9783030457242_12

Don, J.W, Fehr, S, Majenz, C, & Schaffner, C. (2019). Security of the FiatShamir transformation in the Quantum RandomOracle Model. In Advances in Cryptology  CRYPTO 2019 (pp. 356–383). doi:10.1007/9783030269517_13

Fehr, S, & Yuan, C. (2019). Towards optimal robust secret sharing with security against a rushing adversary. In Lecture Notes in Computer Science/Lecture Notes in Artificial Intelligence. doi:10.1007/9783030176594_16

Dupuis, F, Fehr, S, Lamontagne, P, & Salvail, L. (2018). Secure certification of mixed quantum states with application to twoparty randomness generation. In International Conference on Theory of Cryptography (pp. 282–314). doi:10.1007/9783030038106_11

Fehr, S, Karpman, P, & Mennink, B.J.M. (2018). Short nonmalleable codes from relatedkey secure block ciphers. In IACR Transactions on Symmetric Cryptology (pp. 336–352). doi:10.13154/tosc.v2018.i1.336352
Current projects with external funding

Hybrid Approach for quantumsafe Public Key Infrastructure Development for Organisations (HAPKIDO)

PRivacy preserving pOstquantuM systEms from advanced crypTograpHic mEchanisms Using latticeS (PROMETHEUS)
Professional activities
 Editor: Journal: Journal of Cryptology
Grants
 NWO Open Competition (2008)
 Veni Innovational Research Grant NWO (2005)