Jiaxin Pan

I am an Associate Professor (førsteamanuensis) at NTNU (Norway).

Before that I was a postdoc at KIT (Germany) in the group of Dennis Hofheinz. In July 2016 I obtained my PhD from Ruhr-University Bochum (Germany) under the supervision of Eike Kiltz. I am interested in theoretical and practical cryptography in general.

Email: first.last at NTNU.no.

Research Interests

  • Cryptosystems that are scalable (tightly secure) and suitable for Big Data applications

  • Foundations for large-scale privacy, such as (non-interactive) zero-knowledge proof systems

  • Efficient quantum-secure lattice-based cryptosystems

Very recently, I am passionate in proposing and improving security proofs for real-world protocols, which bridges the gap between theoretical and practical cryptography.

Professional Activities

Program Committee Member



  • Journals: ACM Transactions on Algorithms; Journal of Cryptology; Designs, Codes, and Cryptography; IET Information Security; Theoretical Computer Science.

Organizing Committee Member


Teaching Activities

  • Elementary Discrete Mathematics (NTNU, Spring 2021)

  • Cryptography (NTNU, Fall 2020, Fall 2021)

  • Digital Signatures (Lecture at KIT, Winter semester 2018/2019)

  • Cryptographic Protocols (Tutorial at RUB, Summer semester 2015)

  • Several student seminars at both KIT and RUB

Thesis Supervisions

  • Roman Langrehr (Master): Unbounded HIBE with Better Security

    • (Results led to publications at ASIACRYPT and PKC)

  • Benedikt Wagner (Bachelor): Tightly Secure Blind Signatures

    • (It was awarded the SICK Science Award 2019 for the best bachelor thesis )

  • Julia Kastner (Master): On Knowledge Assumptions and the Algebraic Group Model

  • Roman Langrehr (Bachelor): Identity-based Cryptography from Affine MACs

Student Intern

  • Benedikt Wagner from 2019 to 2020

    • (Results led to a publication at PQCrypto 2021)

  • Roman Langrehr from 2018 to 2019.

    • (Results led to an invitation to publish in the Journal of Cryptology)


  • Fine-grained Secure Attribute-based Encryption

with Yuyu Wang and Yu Chen (to appear at CRYPTO 2021)

  • Authenticated Key Exchange and Signatures with Tight Security in the Standard Model

with Shuai Han, Tibor Jager, Eike Kiltz, Shengli Liu, Doreen Riepel, and Sven Schäge (to appear at CRYPTO 2021)

  • Short Identity-Based Signatures with Tight Security from Lattices

with Benedikt Wagner (to appear at PQCRYPTO 2021)

  • Signed Diffie-Hellman Key Exchange with Tight Security

with Chen Qian and Magnus Ringerud (appeared at CT-RSA 2021, full version)

  • Unbounded HIBE with Tight Security

with Roman Langrehr (appeared at ASIACRYPT 2020, full version)

  • Signatures with Tight Multi-User Security from Search Assumptions

with Magnus Ringerud (appeared at ESORICS 2020, full version)

  • Hierarchical Identity-Based Encryption with Tight Multi-Challenge Security

with Roman Langrehr (appeared at PKC 2020, full version)

  • Shorter QA-NIZK and SPS with Tighter Security

with Masayuki Abe, Charanjit Jutla, Miyako Ohkubo, Arnab Roy, and Yuyu Wang (appeared at ASIACRYPT 2019, full version).

  • Tightly Secure Hierarchical Identity-Based Encryption

with Roman Langrehr (appeared at PKC 2019, full version). Invited and accepted to Journal of Cryptology.

  • Identity-Based Encryption Tightly Secure Under Chosen-Ciphertext Attacks

with Dennis Hofheinz and Dingding Jia (appeared at ASIACRYPT 2018, full version).

  • Simple and More Efficient PRFs with Tight Security from LWE and Matrix-DDH

with Tibor Jager and Rafael Kurek (appeared at ASIACRYPT 2018, full version)

  • More Efficient (Almost) Tightly Secure Structure-Preserving Signatures

with Romain Gay, Dennis Hofheinz, and Lisa Kohl (appeared at EUROCRYPT 2018, full version)

  • Tightly-Secure Signatures from Five-Move Identification Protocols

with Eike Kiltz and Julian Loss (appeared at ASIACRYPT 2017, full version)

  • Compact Structure-Preserving Signatures with Almost Tight Security

with Masayuki Abe, Dennis Hofheinz, Ryo Nishimaki, and Miyako Ohkubo (appeared at CRYPTO 2017, full version)

  • Optimal Security Proofs for Signatures from Identification Schemes

with Eike Kiltz and Daniel Masny (appeared at CRYPTO 2016, full version)

  • Unified Security Model of Authenticated Key Exchange with Specific Adversarial Capabilities

with Weiqiang Wen and Libin Wang (appeared at journal of IET Information Security)

  • Structure-Preserving Signatures from Standard Assumptions, Revisited

with Eike Kiltz and Hoeteck Wee (appeared at CRYPTO 2015, full version)

  • Tightly-Secure Signatures from Chameleon Hash Functions

with Olivier Blazy, Saqib A. Kakvi, and Eike Kiltz (appeared at PKC 2015, full version)

  • (Hierarchical) Identity-Based Encryption from Affine Message Authentication

with Olivier Blazy, and Eike Kiltz (appeared at CRYPTO 2014, full version)

You can also check my DBLP for my latest publications.