Lawrence Roy ldr709@gmail.com Postdoc, Aarhus University Updated: February 4, 2026

Research Interests

I research a range of topics related to secure multi-party computation, including oblivious transfer (OT), OT extension, garbled circuits, homomorphic secret sharing, and advanced lattice primitives. I am also interested in formal verification and proofs for cryptography and cybersecurity more generally.

Education

Thesis: “Communication-Efficient Secure Two-Party Computation From Minicrypt and OT”.
Advisor: Mike Rosulek.

Admitted following high school, undergraduate degree requirement waived.
Project: “A Complete Characterization of Security for Linicrypt Block Cipher Modes”.

Publications

I started my research in computer graphics. During my internship at IBM in 2018, I gained some experience in systems security, and its intersection with cryptography. I then switched fully to cryptography in 2019, though I maintain a side interest in systems security. These fields have different author ordering conventions.

Preprint Publications

Publications not in a peer-reviewed conference or journal. These are available only through IACR ePrint or other non-peer-reviewed repositories.

1.

Ivan Damgård, Shravani Patil, Arpita Patra, and Lawrence Roy. New Upper and Lower Bounds for Perfectly Secure MPC. Cryptology ePrint Archive, Paper 2025/1206. 2025. url: https://eprint.iacr.org/2025/1206

2.

Carsten Baum, Ward Beullens, Lennart Braun, Cyprien Delpech de Saint Guilhem, Michael Klooß, Christian Majenz, Shibam Mukherjee, Emmanuela Orsini, Sebastian Ramacher, Christian Rechberger, Lawrence Roy, and Peter Scholl. FAEST: Algorithm Specifications (Version 2.0). Part of NIST PQC Digital Signature Schemes, Round 2. 2025. url: https://faest.info/faest-spec-v2.0.pdf

3.

Damiano Abram, Lawrence Roy, and Mark Simkin. Time-Based Cryptography From Weaker Assumptions: Randomness Beacons, Delay Functions and More. Cryptology ePrint Archive, Report 2024/769. 2024. url: https://eprint.iacr.org/2024/769

Peer-Reviewed Publications

1.

Damiano Abram, Giulio Malavolta, and Lawrence Roy. “Slightly Sublinear Trapdoor Hash Functions and PIR from Low-Noise LPN”. In: TCC 2025, Part I. Ed. by Benny Applebaum and Huijia (Rachel) Lin. Vol. 16268. LNCS. Springer, Cham, Dec. 2025, pp. 280–300. doi: 10.1007/978-3-032-12287-2_10. url: https://eprint.iacr.org/2025/416

2.

Amik Raj Behera, Pierre Meyer, Claudio Orlandi, Lawrence Roy, and Peter Scholl. “Privately Constrained PRFs from DCR: Puncturing and Bounded Waring Rank”. In: TCC 2025, Part I. Ed. by Benny Applebaum and Huijia (Rachel) Lin. Vol. 16268. LNCS. Springer, Cham, Dec. 2025, pp. 301–332. doi: 10.1007/978-3-032-12287-2_11. url: https://eprint.iacr.org/2025/230

3.

Ran Cohen, Jack Doerner, Eysa Lee, Anna Lysyanskaya, and Lawrence Roy. “An Unstoppable Ideal Functionality for Signatures and a Modular Analysis of the Dolev-Strong Broadcast”. In: TCC 2025, Part IV. Ed. by Benny Applebaum and Huijia (Rachel) Lin. Vol. 16271. LNCS. Springer, Cham, Dec. 2025, pp. 675–708. doi: 10.1007/978-3-032-12290-2_22. url: https://eprint.iacr.org/2024/1807

4.

Carsten Baum, Ward Beullens, Lennart Braun, Cyprien Delpech de Saint Guilhem, Michael Klooß, Christian Majenz, Shibam Mukherjee, Emmanuela Orsini, Sebastian Ramacher, Christian Rechberger, Lawrence Roy, and Peter Scholl. “Shorter, Tighter, FAESTer: Optimizations and Improved (QROM) Analysis for VOLE-in-the-Head Signatures”. In: CRYPTO 2025, Part VI. Ed. by Yael Tauman Kalai and Seny F. Kamara. Vol. 16005. LNCS. Springer, Cham, Aug. 2025, pp. 124–156. doi: 10.1007/978-3-032-01887-8_5. url: https://eprint.iacr.org/2026/164

5.

Jake Januzelli, Mike Rosulek, and Lawrence Roy. “Lower Bounds for Garbled Circuits from Shannon-Type Information Inequalities”. In: CRYPTO 2025, Part IV. Ed. by Yael Tauman Kalai and Seny F. Kamara. Vol. 16003. LNCS. Springer, Cham, Aug. 2025, pp. 589–618. url: https://eprint.iacr.org/2025/876

6.

Damiano Abram, Giulio Malavolta, and Lawrence Roy. “Key-Homomorphic Computations for RAM: Fully Succinct Randomised Encodings and More”. In: CRYPTO 2025, Part III. Ed. by Yael Tauman Kalai and Seny F. Kamara. Vol. 16002. LNCS. Springer, Cham, Aug. 2025, pp. 236–268. doi: 10.1007/978-3-032-01881-6_8. url: https://eprint.iacr.org/2025/339

7.

Pierre Meyer, Claudio Orlandi, Lawrence Roy, and Peter Scholl. “Silent Circuit Relinearisation: Sublinear-Size (Boolean and Arithmetic) Garbled Circuits from DCR”. In: CRYPTO 2025, Part IV. Ed. by Yael Tauman Kalai and Seny F. Kamara. Vol. 16003. LNCS. Springer, Cham, Aug. 2025, pp. 426–458. doi: 10.1007/978-3-032-01884-7_14. url: https://eprint.iacr.org/2025/245

8.

Sebastian Kolby, Lawrence Roy, Jure Sternad, and Sophia Yakoubov. “Information-Theoretic Random-Index PIR”. In: ITC 2025. Ed. by Niv Gilboa. Vol. 343. LIPIcs. Schloss Dagstuhl, Aug. 2025, 5:1–5:15. doi: 10.4230/LIPIcs.ITC.2025.5. url: https://eprint.iacr.org/2025/1574

9.

Damiano Abram, Giulio Malavolta, and Lawrence Roy. “Succinct Oblivious Tensor Evaluation and Applications: Adaptively-Secure Laconic Function Evaluation and Trapdoor Hashing for All Circuits”. In: 57th ACM STOC. Ed. by Michal Koucký and Nikhil Bansal. STOC ’25. ACM Press, June 2025, pp. 1875–1886. isbn: 9798400715105. doi: 10.1145/3717823.3718164. url: https://eprint.iacr.org/2025/336

10.

Jake Januzelli, Lawrence Roy, and Jiayu Xu. “Under What Conditions Is Encrypted Key Exchange Actually Secure?” In: EUROCRYPT 2025, Part II. Ed. by Serge Fehr and Pierre-Alain Fouque. Vol. 15602. LNCS. Springer, Cham, May 2025, pp. 451–481. doi: 10.1007/978-3-031-91124-8_16. url: https://eprint.iacr.org/2024/324

11.

Ivan Damgård, Divya Ravi, Lawrence Roy, Daniel Tschudi, and Sophia Yakoubov. “Efficient Secure Communication over Dynamic Incomplete Networks with Minimal Connectivity”. In: TCC 2024, Part IV. Ed. by Elette Boyle and Mohammad Mahmoody. Vol. 15367. LNCS. Springer, Cham, Dec. 2024, pp. 266–292. doi: 10.1007/978-3-031-78023-3_9. url: https://eprint.iacr.org/2024/972

12.

Pierre Meyer, Claudio Orlandi, Lawrence Roy, and Peter Scholl. “Rate-1 Arithmetic Garbling From Homomorphic Secret Sharing”. In: TCC 2024, Part IV. Ed. by Elette Boyle and Mohammad Mahmoody. Vol. 15367. LNCS. Springer, Cham, Dec. 2024, pp. 71–97. doi: 10.1007/978-3-031-78023-3_3. url: https://eprint.iacr.org/2024/820

13.

Carsten Baum, Ward Beullens, Shibam Mukherjee, Emmanuela Orsini, Sebastian Ramacher, Christian Rechberger, Lawrence Roy, and Peter Scholl. “One Tree to Rule Them All: Optimizing GGM Trees and OWFs for Post-Quantum Signatures”. In: ASIACRYPT 2024, Part I. Ed. by Kai-Min Chung and Yu Sasaki. Vol. 15484. LNCS. Springer, Singapore, Dec. 2024, pp. 463–493. doi: 10.1007/978-981-96-0875-1_15. url: https://eprint.iacr.org/2024/490

14.

Carsten Baum, Jens Berlips, Walther Chen, Ivan Bjerre Damgård, Kevin M. Esvelt, Leonard Foner, Dana Gretton, Martin Kysel, Ronald L. Rivest, Lawrence Roy, Francesca Sage-Ling, Adi Shamir, Vinod Vaikuntanathan, Lynn Van Hauwe, Theia Vogel, Benjamin Weinstein-Raun, Daniel Wichs, Stephen Wooster, Andrew C. Yao, and Yu Yu. “Efficient Maliciously Secure Oblivious Exponentiations”. In: CiC 1.3 (2024), p. 10. doi: 10.62056/a66cy7qiu

15.

Maciej Obremski, João Ribeiro, Lawrence Roy, François-Xavier Standaert, and Daniele Venturi. “Improved Reductions from Noisy to Bounded and Probing Leakages via Hockey-Stick Divergences”. In: CRYPTO 2024. Ed. by Leonid Reyzin and Douglas Stebila. Vol. 14925. LNCS. Aug. 2024, pp. 461–491. doi: https://doi.org/10.1007/978-3-031-68391-6_14. url: https://eprint.iacr.org/2024/1009

16.

Damiano Abram, Lawrence Roy, and Peter Scholl. “Succinct Homomorphic Secret Sharing”. In: EUROCRYPT 2024, Part VI. Ed. by Marc Joye and Gregor Leander. Vol. 14656. LNCS. May 2024, pp. 301–330. doi: 10.1007/978-3-031-58751-1_11. url: https://eprint.iacr.org/2024/814

17.

Carsten Baum, Lennart Braun, Cyprien Delpech de Saint Guilhem, Michael Klooß, Emmanuela Orsini, Lawrence Roy, and Peter Scholl. “Publicly Verifiable Zero-Knowledge and Post-Quantum Signatures from VOLE-in-the-Head”. In: CRYPTO 2023, Part V. Ed. by Helena Handschuh and Anna Lysyanskaya. Vol. 14085. LNCS. Aug. 2023, pp. 581–615. doi: 10.1007/978-3-031-38554-4_19. url: https://eprint.iacr.org/2023/996

18.

Yashvanth Kondi, Claudio Orlandi, and Lawrence Roy. “Two-Round Stateless Deterministic Two-Party Schnorr Signatures from Pseudorandom Correlation Functions”. In: CRYPTO 2023, Part I. Ed. by Helena Handschuh and Anna Lysyanskaya. Vol. 14081. LNCS. Aug. 2023, pp. 646–677. doi: 10.1007/978-3-031-38557-5_21. url: https://eprint.iacr.org/2023/216

19.

Diego F. Aranha, Michele Battagliola, and Lawrence Roy. “Faster coercion-resistant e-voting by encrypted sorting”. In: Proceedings of E-Vote-ID 2023. https://e-vote-id.org/. Tartu University Press, June 2023. url: https://eprint.iacr.org/2023/837

20.

Lawrence Roy and Jiayu Xu. “A Universally Composable PAKE with Zero Communication Cost (And Why It Shouldn’t Be Considered UC-Secure)”. In: PKC 2023, Part I. Ed. by Alexandra Boldyreva and Vladimir Kolesnikov. Vol. 13940. May 2023. url: https://eprint.iacr.org/2022/1607

21.

Lawrence Roy. “SoftSpokenOT: Quieter OT Extension from Small-Field Silent VOLE in the Minicrypt Model”. In: CRYPTO 2022, Part I. Ed. by Yevgeniy Dodis and Thomas Shrimpton. Vol. 13507. LNCS. Aug. 2022, pp. 657–687. doi: 10.1007/978-3-031-15802-5_23. url: https://eprint.iacr.org/2022/192

22.

Tommy Hollenberg, Mike Rosulek, and Lawrence Roy. “A Complete Characterization of Security for Linicrypt Block Cipher Modes”. In: CSF 2022 Computer Security Foundations Symposium. IEEE Computer Society Press, Aug. 2022, pp. 439–454. doi: 10.1109/CSF54842.2022.9919676. url: https://eprint.iacr.org/2022/1033

23.

Ian McQuoid, Mike Rosulek, and Lawrence Roy. “Batching Base Oblivious Transfers”. In: ASIACRYPT 2021, Part III. Ed. by Mehdi Tibouchi and Huaxiong Wang. Vol. 13092. LNCS. Dec. 2021, pp. 281–310. doi: 10.1007/978-3-030-92078-4_10. url: https://eprint.iacr.org/2021/682

24.

Honorable Mention for Best Paper!

Mike Rosulek and Lawrence Roy. “Three Halves Make a Whole? Beating the Half-Gates Lower Bound for Garbled Circuits”. In: CRYPTO 2021, Part I. Ed. by Tal Malkin and Chris Peikert. Vol. 12825. LNCS. Virtual Event, Aug. 2021, pp. 94–124. doi: 10.1007/978-3-030-84242-0_5. url: https://eprint.iacr.org/2021/749

25.

Lawrence Roy and Jaspal Singh. “Large Message Homomorphic Secret Sharing from DCR and Applications”. In: CRYPTO 2021, Part III. Ed. by Tal Malkin and Chris Peikert. Vol. 12827. LNCS. Virtual Event, Aug. 2021, pp. 687–717. doi: 10.1007/978-3-030-84252-9_23. url: https://eprint.iacr.org/2021/274

26.

Ian McQuoid, Mike Rosulek, and Lawrence Roy. “Minimal Symmetric PAKE and 1-out-of-N OT from Programmable-Once Public Functions”. In: ACM CCS 2020. Ed. by Jay Ligatti, Xinming Ou, Jonathan Katz, and Giovanni Vigna. ACM Press, Nov. 2020, pp. 425–442. doi: 10.1145/3372297.3417870. url: https://eprint.iacr.org/2020/1043

27.

Lawrence Roy, Stanislav Lyakhov, Yeongjin Jang, and Mike Rosulek. “Practical Privacy-Preserving Authentication for SSH”. In: USENIX Security 2022. Ed. by Kevin R. B. Butler and Kurt Thomas. USENIX Association, Aug. 2022, pp. 3345–3362. url: https://eprint.iacr.org/2022/740

28.

Guerney D. H. Hunt, Ramachandra Pai, Michael V. Le, Hani Jamjoom, Sukadev Bhattiprolu, Rick Boivie, Laurent Dufour, Brad Frey, Mohit Kapur, Kenneth A. Goldman, Ryan Grimm, Janani Janakirman, John M. Ludden, Paul Mackerras, Cathy May, Elaine R. Palmer, Bharata Bhasker Rao, Lawrence Roy, William A. Starke, Jeff Stuecheli, Enriquillo Valdez, and Wendel Voigt. “Confidential Computing for OpenPOWER”. In: Proceedings of the Sixteenth European Conference on Computer Systems. New York, NY, USA: Association for Computing Machinery, 2021, pp. 294–310. isbn: 9781450383349. url: https://doi.org/10.1145/3447786.3456243

29.

Yue Zhang, Lawrence Roy, Ritesh Sharma, and Eugene Zhang. “Maximum Number of Transition Points in 3D Linear Symmetric Tensor Fields”. In: Topological Methods in Data Analysis and Visualization V. Ed. by Hamish Carr, Issei Fujishiro, Filip Sadlo, and Shigeo Takahashi. Springer International Publishing, 2020, pp. 237–250. isbn: 978-3-030-43036-8. url: linear_3d_tensor_field_transition_point.pdf

30.

Botong Qu, Lawrence Roy, Yue Zhang, and Eugene Zhang. “Mode Surfaces of Symmetric Tensor Fields: Topological Analysis and Seamless Extraction”. In: IEEE Transactions on Visualization and Computer Graphics (2020). url: https://arxiv.org/pdf/2009.04601

31.

Fariba Khan, Lawrence Roy, Eugene Zhang, Botong Qu, Shih-Hsuan Hung, Harry Yeh, Robert S Laramee, and Yue Zhang. “Multi-Scale Topological Analysis of Asymmetric Tensor Fields on Surfaces”. In: IEEE Transactions on Visualization and Computer Graphics 26.1 (2019), pp. 270–279. url: https://web.engr.oregonstate.edu/~zhange/images/2Dasymmetric_multiscale.pdf

32.

Lawrence Roy, Prashant Kumar, Yue Zhang, and Eugene Zhang. “Robust and Fast Extraction of 3D Symmetric Tensor Field Topology”. In: IEEE Transactions on Visualization and Computer Graphics 25.1 (2018), pp. 1102–1111. url: http://web.engr.oregonstate.edu/~zhange/images/3DTensorTopology_Detection.pdf

33.

Jonathan Palacios, Lawrence Roy, Prashant Kumar, Chen-Yuan Hsu, Weikai Chen, Chongyang Ma, Li-Yi Wei, and Eugene Zhang. “Tensor Field Design in Volumes”. In: ACM Trans. Graph. 36.6 (Nov. 2017). issn: 0730-0301. doi: 10.1145/3130800.3130844. url: https://web.engr.oregonstate.edu/~zhange/images/3Dtensor_design.pdf

34.

Lawrence Roy, Prashant Kumar, Sanaz Golbabaei, Yue Zhang, and Eugene Zhang. “Interactive Design and Visualization of Branched Covering Spaces”. In: IEEE Transactions on Visualization and Computer Graphics 24.1 (2017), pp. 843–852. doi: 10.1109/TVCG.2017.2744038. url: http://web.engr.oregonstate.edu/~zhange/images/Paper_BCSVis.pdf

35.

Sanaz Golbabaei, Lawrence Roy, Prashant Kumar, and Eugene Zhang. “Construction and Visualization of Branched Covering Spaces”. In: SIGGRAPH ASIA 2016 Technical Briefs. SA ’16. Macau: Association for Computing Machinery, 2016. isbn: 9781450345415. doi: 10.1145/3005358.3005367

Presentations

Recorded Talks

Shorter, Tighter, FAESTer: Optimizations and Improved (QROM) Analysis for VOLE-in-the-Head Signatures
Video ($19min$)
Silent Circuit Relinearisation: Sublinear-Size (Boolean and Arithmetic) Garbled Circuits from DCR
Video ($21min$)

Rate-1 Arithmetic Garbling from Homomorphic Secret-Sharing
Video ($15min$)

Improved Reductions from Noisy to Bounded and Probing Leakages via Hockey-Stick Divergences
Video ($20min$)

Distributed Discrete Logarithms and Applications
Presented jointly with Pierre Meyer.
Pierre’s Part ($36min$), My Part ($34min$)

Succinct Homomorphic Secret Sharing
Video ($22min$)

One Tree to Rule Them All: Optimizing GGM Trees and OWFs for Post-Quantum Signatures
Video ($20min$)

A Universally Composable PAKE with Zero Communication Cost (And Why It Shouldn’t Be Considered UC-Secure)
Video ($17min$)

SoftSpokenOT: Quieter OT Extension From Small-Field Silent VOLE in the Minicrypt Model
Video ($23min$)

Communication-Efficient Secure Two-Party Computation From Minimal Assumptions
Video ($16min$)

SoftSpokenOT: Communication–Computation Tradeoffs in OT Extension
Video ($23min$)

Three Halves Make a Whole? Beating the Half-Gates Lower Bound for Garbled Circuits
Prerecorded Video ($25min$), Live Presentation ($10min$)

Minimal Symmetric PAKE and 1-out-of-N OT from Programmable-Once Public Functions ($10min$)

Honors and Awards

Academic

Capture The Flag (CTF) Competitions¹

Service

Program Committees

Sorted by conference year, not submission year.

Ad Hoc Reviewing

Other