Computer Science Major Honored for Undergraduate Research in Applied Cryptography

Jan 13, 2018

Computer Science major Julia Len recently got word that she was a recipient of a prestigious award honoring outstanding undergraduate researchers. The awards are given annually by the Computing Research Association (CRA) to undergrads at North American universities who show "outstanding research potential in an area of computing research." The very competitive CRA program selected four awardees, four runners-up, 14 finalists and 48 honorable mentions. Len won in the runners-up category. She is the first student from UC San Diego to get this far in the CRA competition.

5th-year CS undergrad Julia Len

Len  was recognized for research in applied cryptography. She helped develop cryptographic hash functions that provided provable security guarantees. "Hash functions are some of the most vital cryptographic tools," noted Len. "For example, the TLS protocol underlying HTTPS -- which we rely on for everyday interactions with popular websites -- uses hash functions to create digital certificates that authenticate servers. If an adversary were to find a collision for such a hash function, certificates could be forged and allow servers to be impersonated, putting personal information at risk of theft."

"Our project improved the design of hash functions constructed using the Merkle-Damgard transform," she added. "The most commonly utilized hash functions are constructed using the Merkle-Damgard transform, which iterates a compression function to produce a hash function. Our work proved that weakening the condition on the compression function would still result in a collision-resistant hash function."

Len's work, done in collaboration with Ph.D. student Joseph Jaeger, began in CSE 191, a Projects in Cryptography course taught by Prof. Mihir Bellare. The three published an academic paper on the subject at the 2017 ACM Computer and Communications Security Conference (CCS). On behalf of her coauthors, Len flew to Dallas last November and presented their joint paper* on collision-resistant hashing at the 2017 ACM Computer and Communications Security Conference (CCS). The meeting brings together information security researchers, practitioners, developers and users from all over the world to explore cutting-edge ideas and results. (Also attending CCS 2017 -- to accept the CCS Test of Time Award -- was CSE professor and security researcher Hovav Shacham.)

According to Prof. Bellare, Len contributed to a method for designing hash functions that are less likely to fail in the future. "Her work provides new design paradigms that yield hash functions with improved provable-security guarantees, decreasing the likelihood of failure and moving us towards greater security in future Internet communications," observed Bellare. "Julia obtains this as part of a general framework that also explains the weaknesses of the current design paradigm and unifies different approaches and results in the area."

"Julia has done innovative, timely, real world-relevant research in cryptography leading to a paper she co-authored at CCS 2017, considered to be a first-tier conference in security and cryptography," Bellare noted in a letter nominating Len for the CRA award. "She also presented the paper in Dallas. It's very rare for an undergraduate to present at a first-tier conference, and much of the work was done while she was a junior!"

Len is a former president of the UC San Diego Scholars Society and is active in the UC San Diego chapter of Women in Computing. She became a CSE Tutor in Spring 2016, and since then has tutored for courses including Introduction to Modern Cryptography (CSE 107), Theory of Computability (CSE 105), Discrete Mathematics (CSE 20), and Computer Organization and Systems Programming (CSE 30). Len was also head tutor for the popular lower-division course, Introduction to Computer Science and Object-Oriented Programming: Java (CSE 11).

A Regents Scholar, Len is looking forward to graduating this June, and she has already applied to multiple Ph.D. programs in Computer Science. She plans to pursue cryptography research for her doctorate, and isn't wasting any time: she wants to start grad school this fall.


*Bellare, M., Jaeger, J., & Len, J. (2017, October). “Better Than Advertised: Improved Collision-Resistance Guarantees for MD-Based Hash Functions.” In Proceedings of the 2017 ACM SIGSAC Conference on Computer and Communications Security (pp. 891-906). ACM.  

CRA 2018 Outstanding Undergraduate Research Award Winners 
Streaming Video of Julia Len Presentation at CCS 2017