Ziyan Chen
Post-quantum cryptography
Mathematical ideas underlie public-key cryptography: a method of conveying protected information on open channels. The most widely used ideas are the Rivest-Shamir-Adleman (RSA) public-key algorithm and elliptic curve cryptography, and they rely on the difficulty of factorising large numbers. The trouble is that when sufficiently powerful quantum computers are available, large integers will be factorised quickly, and so we need new mathematical ideas that will be difficult to decode, even for quantum computers. This project explores two mathematical directions: braid groups and modular lattices
Ziyan Chen
The University of Sydney
Ziyan (Andy) Chen is a Bachelor of Science student in Computer Science and Mathematics at the University of Sydney, where he maintains a WAM above 90. His academic recognitions include the 2024 Dean’s List of Excellence (with Academic Merit Prize) and the 2023 Vice-Chancellor’s International Scholarship.
His research spans machine learning theory, optimization, and applied finance. He is currently a research assistant at Macquarie University on a multimodal loan-default prediction project, and previously a Winter research student at Monash University working on SCIPPlan with a focus on constraint generation and stochastic extensions. At USYD, he investigates theoretical aspects of machine learning — most recently a study applying Neural Collapse ideas to imitate optimal policy in reinforcement learning and another study of exploring covariance-aware key-value cache compression in large language model. Earlier, he contributed to a meme-coin trading study with panel regression analyses.
Beyond academia, he interned at China Merchants Bank (Sydney), producing sector briefs and supporting the “Future Banker” program, and at Shanghai Huicheng, where he built an ETF arbitrage background and completed CTA arbitrage program. Apart from that, he took part in U21 Global Citizen in 2025 and won micro-credential.
