About me

I am a postdoctoral scholar at Stanford University's Computer Science Department, hosted by Prof. Dan Boneh. My main area of research is applied cryptography. I am particularly excited about research questions that are driven by real-world applications of cryptography, and connect practical challenges with foundational aspects of computation.
I am a Protocol Labs Postdoctoral Fellow and a Rothschild Postdoctoral Fellow.

Before joining Stanford, I completed my Ph.D. in Computer Science at the Hebrew University's School of Computer Science and Engineering, where I was fortunate to be advised by Prof. Gil Segev.
During my Ph.D. I was an Adams Fellow of the Israel Academy of Sciences and Humanities.

Contact

Office: Gates Computer Science Building, Room 188
Email: lrotem at cs.stanford.edu

Publications

  • Lior Rotem and Stefano Tessaro
    Straight-Line Knowledge Extraction for Multi-Round Protocols
    [PDF]

  • Dan Boneh, Aditi Partap, and Lior Rotem
    Traceable Secret Sharing: Strong Security and Efficient Constructions
    Advances in Cryptology - CRYPTO, 2024.
    [PDF]

  • Dan Boneh, Aditi Partap, and Lior Rotem
    Accountability for Misbehavior in Threshold Decryption via Threshold Traitor Tracing
    Advances in Cryptology - CRYPTO, 2024.
    Also presented at the Science of Blockchain Conference (SBC), 2024.
    [PDF]

  • Dan Boneh, Aditi Partap, and Lior Rotem
    Proactive Refresh for Accountable Threshold Signatures
    Financial Cryptography and Data Security (FC), 2024.
    [PDF]

  • Lior Rotem, Gil Segev, and Eylon Yogev
    From One-Time to Two-Round Reusable Multi-Signatures without Nested Forking
    Theory of Cryptography Conference (TCC), 2024.
    [PDF]

  • Dan Boneh, Aditi Partap, and Lior Rotem
    Post-Quantum Single Secret Leader Election (SSLE) From Publicly Re-randomizable Commitments
    ACM Advances in Financial Technologies (AFT), 2023.
    Also presented at the Science of Blockchain Conference (SBC), 2023.
    [PDF]

  • Lior Rotem
    Revisiting the Uber Assumption in the Algebraic Group Model: Fine-Grained Bounds in Hidden-Order Groups and Improved Reductions in Bilinear Groups
    Information-Theoretic Cryptography (ITC), 2022.
    [PDF]

  • Lior Rotem and Gil Segev
    A Fully-Constructive Discrete-Logarithm Preprocessing Algorithm with an Optimal Time-Space Tradeoff
    Information-Theoretic Cryptography (ITC), 2022.
    [PDF]

  • Lior Rotem
    Simple and Efficient Batch Verification Techniques for Verifiable Delay Functions
    Theory of Cryptography Conference (TCC), 2021.
    [PDF]

  • Lior Rotem and Gil Segev
    Non-Malleable Vector Commitments via Local-Equivocability
    Theory of Cryptography Conference (TCC), 2021.
    Journal of Cryptology, 2023.
    [PDF]

  • Lior Rotem and Gil Segev
    Tighter Security for Schnorr Identification and Signatures: A High-Moment Forking Lemma for Σ-Protocols
    Advances in Cryptology - CRYPTO, 2021.
    Journal of Cryptology, 2024.
    [PDF]

  • Lior Rotem and Gil Segev
    Algebraic Distinguishers: From Discrete Logarithms to Decisional Uber Assumptions
    Theory of Cryptography Conference (TCC), 2020.
    [PDF]

  • Lior Rotem and Gil Segev
    Generically Speeding-Up Repeated Squaring is Equivalent to Factoring: Sharp Thresholds for All Generic-Ring Delay Functions
    Advances in Cryptology - CRYPTO, 2020.
    [PDF]

  • Lior Rotem, Gil Segev, and Ido Shahaf
    Generic-Group Delay Functions Require Hidden-Order Groups
    Advances in Cryptology - EUROCRYPT, 2020.
    [PDF]

  • Moni Naor, Lior Rotem, and Gil Segev
    Out-of-Band Authenticated Group Key Exchange: From Strong Authentication to Immediate Key Delivery
    Information-Theoretic Cryptography (ITC), 2020.
    [PDF]

  • Lior Rotem and Gil Segev
    Out-of-Band Authentication in Group Messaging: Computational, Statistical, Optimal
    Advances in Cryptology - CRYPTO, 2018.
    [PDF]

  • Lior Rotem and Gil Segev
    Injective Trapdoor Functions via Derandomization: How Strong is Rudich's Black-Box Barrier?
    Theory of Cryptography Conference (TCC), 2018.
    Journal of Cryptology, 2021.
    [PDF]

  • Moni Naor, Lior Rotem, and Gil Segev
    The Security of Lazy Users in Out-of-Band Authentication
    Theory of Cryptography Conference (TCC), 2018.
    ACM Transactions on Privacy and Security (TOPS), 2020.
    [PDF]

  • Ran Cohen, Iftach Haitner, Eran Omri, and Lior Rotem
    From Fairness to Full Security in Multiparty Computation
    Security and Cryptography for Networks (SCN), 2018.
    Journal of Cryptology, 2021.
    [PDF]

  • Ran Cohen, Iftach Haitner, Eran Omri, and Lior Rotem
    Characterization of Secure Multiparty Computation Without Broadcast
    Theory of Cryptography Conference (TCC), 2016.
    Journal of Cryptology, 2018.
    [PDF]

Program Committees

  • The 44th Annual International Conference on the Theory and Applications of Cryptographic Techniques (EUROCRYPT), 2025.
  • The 22th Theory of Cryptography Conference (TCC), 2024.
  • The 4th Information-Theoretic Cryptography Conference (ITC), 2023.
  • The 20th Theory of Cryptography Conference (TCC), 2022.
  • The 42nd International Cryptology Conference (CRYPTO), 2022.

Teaching