I am a 2nd-year PhD student in the Computer Science Theory Group at Columbia University, co-advised by Tal Malkin and Henry Yuen. My research is at the intersection of cryptography and quantum computing, with an emphasis on quantum cryptography (not quite a tautology, I promise 🙂).

Previously I attended UT Austin, where I studied Computer Science and Mathematics with a Minor in Chinese, and worked as an undergraduate researcher with David Soloveichik on theoretical aspects of molecular and unconventional computing.

I enjoy learning languages, doing the NYT crossword and other puzzles (especially puzzle hunts), and skiing.

I would have loved the URL leoorshan.sky, but it was taken. On the other hand, I am an avid skier :)

Email: first-initial last-initial 2433 at columbia dot edu

Links: Google Scholar · CV

Selected Publications

Full publication list.

How To Track Qubits Through Space and Time (Or: Sailing in a Quantum Boat). J Bartusek, Z Huang, L Orshansky, H Yuen. 2026. Forthcoming to arXiv.
Private proofs of when and where. U Girish, G Gluch, S Goldwasser, T Malkin, L Orshansky, H Yuen. 2026. [arXiv, eprint]
Comparing classical and quantum conditional disclosure of secrets. U Girish, A May, L Orshansky, C Waddell. Quantum 10, 2049 (2025). [arXiv]