苏杭 | Hang Su

Cryptography Research and Engineering

Email: hs2nu@virginia.edu

Github: tonyfloatersu

Blog: Nomad Note

[CV, Google Scholar]

Research Interest

Cryptography, Computer Security, Theoretical Computer Science (in general aspect).

Education

Publications

[1] Shorter and Faster Post-Quantum Designated-Verifier zkSNARKs from Lattices

Yuval Ishai, Hang Su, and David J. Wu. In ACM CCS 2021.

[Paper (ePrint Version)] [Sample Implementation]

Research Experience

Research Assistant advised by David J. Wu at University of Virginia, Jan., 2020 - May., 2021

Research Topic: Zero-Knowledge Succinct Non-Interactive Argument of Knowledge (zkSNARK) from Lattice-Based Cryptography Assumption.

  • Implemented a lattice-based post-quantum secure zkSNARK over extension fields with smaller parameters.
  • Designed and implemented an encryption scheme from Module-Learning-With-Error (MLWE) cryptographic assumption.
  • Developed a variant Fast Fourier Transform (FFT) over cosets for fields with small characteristics.
  • Obtained 10.3x smaller proof size than previous post-quantum candidates.
  • Achieved 42.1x smaller proof size and 60.2x faster prover time than prior lattice-based candidates, with a much higher level of soundness.
  • Published a first-authored full length paper at ACM CCS 2021, Seoul, South Korea.

Industry Experience

Cryptography Researcher, Cysic Labs., Oct., 2023 - Oct., 2024

Software Engineer, Algorand Inc., Jul., 2021 - Sept., 2023

Github: ahangsu

Worked with the smart contract team on Algorand Virtual Machine (AVM) programmability and safety.

  • Provided the first prototype of Application Binary Interface (ABI) for smart contract interoperability.
  • Developed features and integrated Behavior Driven Development (BDD) tests for SDKs.
  • Designed and implemented PyTeal library for smart contract development.
  • Lead the development for the Simulation Endpoint:
    • Allows a local node to simulate transactions without committing them to the network.
    • Exports fine-grained opcode-by-opcode execution traces for invoked smart contracts.
    • Improves live chain data querying flexibility by utilizing TEAL as a query language.
  • Prototyped a brand new smart contract debugger by taking advantage of the Simulation Endpoint.

Teaching Experience

Served over 200 students in UM-SJTU-JI.

  • Teaching Assistant for VE216 (Signals and Systems), Shanghai Jiao Tong University, May., 2018 - Aug., 2018
    • Led weekly lab sessions, and held weely office hours.
    • Assisted instructor in designing exams and projects.
  • Teaching Assistant for VE482 (Operating System), Shanghai Jiao Tong University, Sep., 2018 - Dec., 2018
    • Led weekly recitation class, and graded homework assignments and exams.
    • Maintained the course grading server for institute, served over 100 students.

Notes

Sometimes, I will post notes taken for some courses / papers:

MISC

I have many awesome friends over the years, and you may find their stuffs interesting: