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Informatics Institute Informatics Institute

Prof. dr. C. (Christian) Schaffner

Faculty of Science
Informatics Institute
Photographer: Bastiaan Heus
Visiting address
  • Science Park 900
  • Room number: L6.07
Postal address
  • Postbus 19268
    1000 GG Amsterdam
Contact details
Social media
  • Positions and Homepage

    Positions

    Professor in Theoretical Computer Science at Informatics Institute, group leader of the Theory of Computer Science (TCS) group.

    Director of QuSoft, Research Center for Quantum Software

    Chairman of Quantum.Amsterdam, innovation hub for quantum software, technology and applications

    co-PI of Challenges in Cyber Security gravitation project.

    Personal Homepage

    personal homepage at https://staff.science.uva.nl/c.schaffner/

  • Publications

    2024

    2022

    • Don, J., Fehr, S., Majenz, C., & Schaffner, C. (2022). Efficient NIZKs and Signatures from Commit-and-Open Protocols in the QROM. In Y. Dodis, & T. Shrimpton (Eds.), Advances in Cryptology – CRYPTO 2022: 42nd Annual International Cryptology Conference, CRYPTO 2022, Santa Barbara, CA, USA, August 15–18, 2022 : proceedings (Vol. II, pp. 729-757). (Lecture Notes in Computer Science; Vol. 13508). Springer. https://doi.org/10.1007/978-3-031-15979-4_25 [details]
    • Don, J., Fehr, S., Majenz, C., & Schaffner, C. (2022). Online-Extractability in the Quantum Random-Oracle Model. In O. Dunkelman, & S. Dziembowski (Eds.), Advances in Cryptology – EUROCRYPT 2022: 41st Annual International Conference on the Theory and Applications of Cryptographic Techniques, Trondheim, Norway, May 30–June 3, 2022 : proceedings (Vol. III, pp. 677-706). (Lecture Notes in Computer Science; Vol. 13277). Springer. https://doi.org/10.1007/978-3-031-07082-2_24 [details]

    2021

    • Alagic, G., Brakerski, Z., Dulek, Y., & Schaffner, C. (2021). Impossibility of Quantum Virtual Black-Box Obfuscation of Classical Circuits. In T. Malkin, & C. Peikert (Eds.), Advances in Cryptology – CRYPTO 2021: 41st Annual International Cryptology Conference, CRYPTO 2021, virtual event, August 16–20, 2021 : proceedings (Vol. I, pp. 497-525). (Lecture Notes in Computer Science; Vol. 12825). Springer. https://doi.org/10.1007/978-3-030-84242-0_18 [details]

    2020

    • Dulek, Y., Grilo, A. B., Jeffery, S., Majenz, C., & Schaffner, C. (2020). Secure multi-party quantum computation with a dishonest majority. In A. Canteaut, & Y. Ishai (Eds.), Advances in Cryptology – EUROCRYPT 2020: 39th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Zagreb, Croatia, May 10–14, 2020 : proceedings (Vol. III, pp. 729-758). (Lecture Notes in Computer Science; Vol. 12107). Springer. https://doi.org/10.1007/978-3-030-45727-3_25 [details]
    • Landerreche, E., Stevens, M., & Schaffner, C. (2020). Non-interactive Cryptographic Timestamping Based on Verifiable Delay Functions. In J. Bonneau, & N. Heninger (Eds.), Financial Cryptography and Data Security: 24th International Conference, FC 2020, Kota Kinabalu, Malaysia, February 10–14, 2020, Revised Selected Papers (pp. 541-558). (Lecture Notes in Computer Science; No. 12059). Springer. https://doi.org/10.1007/978-3-030-51280-4_29 [details]

    2019

    • Coopmans, T., Kaniewski, J., & Schaffner, C. (2019). Robust self-testing of two-qubit states. Physical Review A, 99(5), Article 052123. https://doi.org/10.1103/PhysRevA.99.052123 [details]
    • Czajkowski, J., Hülsing, A., & Schaffner, C. (2019). Quantum Indistinguishability of Random Sponges. In A. Boldyreva, & D. Micciancio (Eds.), Advances in Cryptology – CRYPTO 2019: 39th Annual International Cryptology Conference, Santa Barbara, CA, USA, August 18–22, 2019 : proceedings (Vol. 2, pp. 296-325). (Lecture Notes in Computer Science; Vol. 11693). Springer. https://doi.org/10.1007/978-3-030-26951-7_11 [details]
    • Don, J., Fehr, S., Majenz, C., & Schaffner, C. (2019). Security of the Fiat-Shamir Transformation in the Quantum Random-Oracle Model. In A. Boldyreva, & D. Micciancio (Eds.), Advances in Cryptology – CRYPTO 2019: 39th Annual International Cryptology Conference, Santa Barbara, CA, USA, August 18–22, 2019 : proceedings (Vol. 2, pp. 356-383). (Lecture Notes in Computer Science; Vol. 11693). Springer. https://doi.org/10.1007/978-3-030-26951-7_13 [details]

    2018

    2017

    • Alagic, G., Dulek, Y., Schaffner, C., & Speelman, F. (2017). Quantum Fully Homomorphic Encryption with Verification. In T. Takagi, & T. Peyrin (Eds.), Advances in Cryptology – ASIACRYPT 2017: 23rd International Conference on the Theory and Applications of Cryptology and Information Security, Hong Kong, China, December 3-7, 2017 : proceedings (Vol. 1, pp. 438-467). (Lecture Notes in Computer Science; Vol. 10624). Springer. https://doi.org/10.1007/978-3-319-70694-8_16 [details]
    • Santoli, T., & Schaffner, C. (2017). Using Simon's Algorithm to Attack Symmetric-Key Cryptographic Primitives. Quantum Information & Computation, 17(1&2), 65-78. https://arxiv.org/abs/1603.07856 [details]

    2016

    • Alagic, G., Broadbent, A., Fefferman, B., Gagliardoni, T., Schaffner, C., & St. Jules, M. (2016). Computational security of quantum encryption. In A. C. A. Nascimento, & P. Barreto (Eds.), Information Theoretic Security: 9th International Conference, ICITS 2016, Tacoma, WA, USA, August 9–12, 2016 : revised selected papers (pp. 47-71). (Lecture Notes in Computer Science; Vol. 10015). Springer. https://doi.org/10.1007/978-3-319-49175-2_3 [details]
    • Broadbent, A., & Schaffner, C. (2016). Quantum cryptography beyond quantum key distribution. Designs, Codes and Cryptography, 78(1), 351-382. Advance online publication. https://doi.org/10.1007/s10623-015-0157-4 [details]
    • Dulek, Y., Schaffner, C., & Speelman, F. (2016). Quantum homomorphic encryption for polynomial-sized circuits. In M. Robshaw, & J. Katz (Eds.), Advances in Cryptology – CRYPTO 2016: 36th Annual International Cryptology Conference, Santa Barbara, CA, USA, August 14-18, 2016 : proceedings (Vol. 3, pp. 3-32). (Lecture Notes in Computer Science; Vol. 9816). Springer. https://doi.org/10.1007/978-3-662-53015-3_1 [details]
    • Gagliardoni, T., Hülsing, A., & Schaffner, C. (2016). Semantic security and indistinguishability in the quantum world. In M. Robshaw, & J. Katz (Eds.), Advances in Cryptology – CRYPTO 2016: 36th Annual International Cryptology Conference, Santa Barbara, CA, USA, August 14-18, 2016 : proceedings (Vol. 3, pp. 60-89). (Lecture Notes in Computer Science; Vol. 9816). Springer. https://doi.org/10.1007/978-3-662-53015-3_3 [details]

    2015

    • Piovesan, T., Scarpa, G., & Schaffner, C. (2015). Multiparty Zero-Error Classical Channel Coding With Entanglement. IEEE Transactions on Information Theory, 61(2), 1113-1123. Advance online publication. https://doi.org/10.1109/TIT.2014.2379273 [details]
    • Salvail, L., Schaffner, C., & Sotáková, M. (2015). Quantifying the leakage of quantum protocols for classical two-party cryptography. International Journal of Quantum Information, 13(4), Article 1450041. Advance online publication. https://doi.org/10.1142/S0219749914500415 [details]

    2014

    • Buhrman, H., Chandran, N., Fehr, S., Gelles, R., Goyal, V., Ostrovsky, R., & Schaffner, C. (2014). Position-based quantum cryptography: Impossibility and constructions. SIAM Journal on Computing, 43(1), 150-178. https://doi.org/10.1137/130913687 [details]
    • Buhrman, H., Fehr, S., & Schaffner, C. (2014). On the Parallel Repetition of Multi-Player Games: The No-Signaling Case. In S. T. Flammia, & A. W. Harrow (Eds.), 9th Conference on the Theory of Quantum Computation, Communication and Cryptography: TQC 2014, May 21-23, 2014, National University of Singapore, Singapore (pp. 24-35). (Leibniz International Proceedings in Informatics; Vol. 27). Schloss Dagstuhl - Leibniz-Zentrum für Informatik. https://doi.org/10.4230/LIPIcs.TQC.2014.24 [details]
    • Damgård, I., Fehr, S., Salvail, L., & Schaffner, C. (2014). Secure identification and QKD in the bounded-quantum-storage model. Theoretical Computer Science, 560(1), 12-26. https://doi.org/10.1016/j.tcs.2014.09.014 [details]

    2013

    • Bouman, N. J., Fehr, S., González-Guillén, C., & Schaffner, C. (2013). An all-but-one entropic uncertainty relation, and application to password-based identification. In K. Iwama, Y. Kawano, & M. Murao (Eds.), Theory of Quantum Computation, Communication, and Cryptography: 7th Conference, TQC 2012, Tokyo, Japan, May 17-19, 2012: revised selected papers (pp. 29-44). (Lecture Notes in Computer Science; Vol. 7582). Springer. https://doi.org/10.1007/978-3-642-35656-8_3 [details]
    • Buhrman, H., Fehr, S., Schaffner, C., & Speelman, F. (2013). The Garden-Hose Model. In ITCS'13: proceedings of the 2013 ACM Conference on Innovations in Theoretical Computer Science : January 9-12, 2013, Berkeley, California, USA (pp. 145-157). Association for Computing Machinery. https://doi.org/10.1145/2422436.2422455 [details]
    • Buhrman, H., van der Gulik, P. T. S., Klau, G. W., Schaffner, C., Speijer, D., & Stougie, L. (2013). A Realistic Model Under Which the Genetic Code is Optimal. Journal of molecular evolution, 77(4), 170-184. Advance online publication. https://doi.org/10.1007/s00239-013-9571-2 [details]
    • Fehr, S., Gelles, R., & Schaffner, C. (2013). Security and Composability of Randomness Expansion from Bell Inequalities. Physical Review A, 87(1), Article 012335. https://doi.org/10.1103/PhysRevA.87.012335 [details]

    2012

    2011

    • Boneh, D., Dagdelen, Ö., Fischlin, M., Lehmann, A., Schaffner, C., & Zhandry, M. (2011). Random Oracles in a Quantum World. In D. H. Lee, & X. Wang (Eds.), Advances in Cryptology – ASIACRYPT 2011: 17th International Conference on the Theory and Application of Cryptology and Information Security, Seoul, South Korea, December 4-8, 2011 : proceedings (pp. 41-69). (Lecture Notes in Computer Science; Vol. 7073). Springer. https://doi.org/10.1007/978-3-642-25385-0_3 [details]
    • Buhrman, H., Chandran, N., Fehr, S., Gelles, R., Goyal, V., Ostrovsky, R., & Schaffner, C. (2011). Position-based quantum cryptography: impossibility and constructions. In P. Rogaway (Ed.), Advances in Cryptology – CRYPTO 2011: 31st Annual Cryptology Conference, Santa Barbara, CA, USA, August 14-18, 2011: proceedings (pp. 429-446). (Lecture Notes in Computer Science; Vol. 6841). Springer. https://doi.org/10.1007/978-3-642-22792-9_24 [details]
    • Tomamichel, M., Schaffner, C., Smith, A., & Renner, R. (2011). Leftover Hashing Against Quantum Side Information. IEEE Transactions on Information Theory, 57(8), 5524-5535. https://doi.org/10.1109/TIT.2011.2158473 [details]

    2010

    2009

    • Damgård, I., Fehr, S., Lunemann, C., Salvail, L., & Schaffner, C. (2009). Improving the security of quantum protocols via commit-and-open. In Advances in Cryptology - CRYPTO 2009 - 29th Annual International Cryptology Conference, Proceedings (pp. 408-427). (Lecture Notes in Computer Science; Vol. 5677). Springer. https://doi.org/10.1007/978-3-642-03356-8_24
    • Fehr, S., & Schaffner, C. (2009). Composing quantum protocols in a classical environment. In Theory of Cryptography - 6th Theory of Cryptography Conference, TCC 2009, Proceedings (pp. 350-367). (Lecture Notes in Computer Science; Vol. 5444). Springer. https://doi.org/10.1007/978-3-642-00457-5_21
    • König, R., Renner, R., & Schaffner, C. (2009). The operational meaning of min- and max-entropy. IEEE Transactions on Information Theory, 55(9), 4337-4347. https://doi.org/10.1109/TIT.2009.2025545
    • Salvail, L., Schaffner, C., & Sotáková, M. (2009). On the power of two-party quantum cryptography. In Advances in Cryptology - ASIACRYPT 2009 - 15th International Conference on the Theory and Application of Cryptology and Information Security, Proceedings (pp. 70-87). (Lecture Notes in Computer Science; Vol. 5912). Springer. https://doi.org/10.1007/978-3-642-10366-7_5
    • Schaffner, C., Terhal, B., & Wehner, S. (2009). Robust cryptography in the noisy-quantum-storage model. Quantum Information & Computation, 9(11-12), 963-996. https://doi.org/10.26421/QIC9.11-12

    2008

    • Fehr, S., & Schaffner, C. (2008). Randomness extraction via δ-biased masking in the presence of a quantum attacker. In Theory of Cryptography - Fifth Theory of Cryptography Conference, TCC 2008, Proceedings (pp. 465-481). (Lecture Notes in Computer Science; Vol. 4948). Springer. https://doi.org/10.1007/978-3-540-78524-8_26

    2007

    • Damgård, I. B., Fehr, S., Renner, R., Salvail, L., & Schaffner, C. (2007). A tight high-order entropie quantum uncertainty relation with applications. In Advances in Cryptology - CRYPTO 2007 - 27th Annual International Cryptology Conference, Proceedings (pp. 360-378). (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics); Vol. 4622 LNCS). Springer Verlag. https://doi.org/10.1007/978-3-540-74143-5_20

    2006

    • Crépeau, C., Savvides, G., Schaffner, C., & Wullschleger, J. (2006). Information-theoretic conditions for two-party secure function evaluation. In Advances in Cryptology - EUROCRYPT 2006 - 24th Annual International Conference on the Theory and Applications of Cryptographic Techniques, Proceedings (pp. 538-554). (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics); Vol. 4004 LNCS). Springer Verlag. https://doi.org/10.1007/11761679_32
    • Damgård, I. B., Fehr, S., Salvail, L., & Schaffner, C. (2006). Oblivious transfer and linear functions. In Advances in Cryptology - CRYPTO 2006 - 26th Annual International Cryptology Conference, Proceedings (pp. 427-444). (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics); Vol. 4117 LNCS). Springer Verlag. https://doi.org/10.1007/11818175_26

    2005

    • Damgård, I. B., Fehr, S., Salvail, L., & Schaffner, C. (2005). Cryptography in the bounded quantum-storage model. In IEEE Information Theory Workshop on Theory and Practice in Information-Theoretic Security, 2005 (pp. 24-27). IEEE. https://doi.org/10.1109/ITWTPI.2005.1543950

    2022

    2016

    • VC3BI commissie, Sandberg, J., Belleman, R., Bredeweg, B., Visser, A., Endriss, U., Roelofsen, F., Schaffner, C., van Schoot, T., Sluijter, B., Fokkink, W., Haasdijk, E., de Boer, V., & Klein, M. (2016). Eindrapport VC3BI commissie. UvA. [details]

    Membership / relevant position

    • Schaffner, C. (2016). PC member, TQC 2016, Berlin.
    • Schaffner, C. (2015-). PC member, 10th Conference on the Theory of Quantum Computation, Communication and Cryptography (TQC 2015).

    Media appearance

    Journal editor

    Talk / presentation

    • Schaffner, C. (speaker) (17-3-2020). Secure Multi-Party Quantum Computation with a Dishonest Majority, The Quantum Wave in Computing, Berkeley. https://www.youtube.com/watch?v=JWeMpFlc8Jo
    • Schaffner, C. (speaker) (3-4-2019). Landing Festival Berlin, Landing Festival, Berlin.
    • Schaffner, C. (speaker) (13-1-2018). Tutorial on Quantum Cryptography Beyond Key Distribution, Quantum Information Processing 2018, Delft.
    • Schaffner, C. (speaker) (2018). Towards obfuscation using quantum homomorphic encryption, Workshop on cryptography in the quantum age.
    • Schaffner, C. (speaker) (2018). Invited Tutorial, QCALL Secure Quantum Communications (SQC) School.

    Others

    • Schaffner, C. (organiser) & Fehr, S. (organiser) (10-8-2020 - 14-8-2020). QCrypt 2020, Amsterdam (organising a conference, workshop, ...). https://2020.qcrypt.net/team/
    • Schaffner, C. (visiting researcher) (10-12-2019 - 15-6-2020). Simons Institute for the Theory of Computing (visiting an external institution).

    2024

    • Sotáková, J. (2024). Isogenies and cryptography. [Thesis, fully internal, Universiteit van Amsterdam]. [details]

    2022

    • Czajkowski, J. M. (2022). Post-quantum security of hash functions. [Thesis, fully internal, Universiteit van Amsterdam]. Institute for Logic, Language and Computation. [details]

    2021

    • Dulek, Y. M. (2021). Delegated and distributed quantum computation. [Thesis, fully internal, Universiteit van Amsterdam]. Institute for Logic, Language and Computation. [details]
    This list of publications is extracted from the UvA-Current Research Information System. Questions? Ask the library or the Pure staff of your faculty / institute. Log in to Pure to edit your publications. Log in to Personal Page Publication Selection tool to manage the visibility of your publications on this list.
  • Ancillary activities
    • Quantum Gateway Solutions BV
      Scientific advisor
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