Computer Science & Discrete Mathematics (CSDM)

Computer Science & Discrete Mathematics (CSDM) Seminar

A weekly seminar on topics in theoretical computer science and discrete mathematics

Time: Every Monday 11:00 AM-12:00 PM, and Tuesday 10:30 AM-12:30 PM,   Place: Simonyi 101

Information about CSDM

Upcoming Talk

Obfuscation is a Wheelbarrow: How to Build Long-Sought Cryptography Using Complexity Theory

Speaker: Rahul Ilango, Institute for Advanced Study
When: Tuesday, February 17, 2026 | 10:30 AM EST
Where: Simonyi 101 and Remote Access

Abstract

Over the past 50 years, cryptographers have constructed a number of surprising and important primitives like public-key encryption, which allows strangers to communicate privately even if eavesdroppers hear everything they say. However, there are still many basic primitives that cryptographers believe should exist but have not yet been able to construct.

In this talk, I’ll describe a powerful new complexity-theoretic approach to constructing cryptographic primitives. This approach has already led to multiple long-sought constructions, including public-key encryption with “optimal” security. A key idea is to use “circuit obfuscators” (I’ll explain what these are) to transfer statements from complexity theory to cryptography.

No background in cryptography assumed. Based on joint work with Alex Lombardi (https://eprint.iacr.org/2025/1087). 

Add to calendar 02/17/2026 10:3002/17/2026 12:30America/New_YorkComputer Science/Discrete Mathematics Seminar IIuse-titleTopic: Obfuscation is a Wheelbarrow: How to Build Long-Sought Cryptography Using Complexity Theory Speakers: Rahul Ilango, Institute for Advanced Study More: https://www.ias.edu/math/events/computer-sciencediscrete-mathematics-seminar-ii-612 Over the past 50 years, cryptographers have constructed a number of surprising and important primitives like public-key encryption, which allows strangers to communicate privately even if eavesdroppers hear everything they say. However, there are still many basic primitives that cryptographers believe should exist but have not yet been able to construct. In this talk, I’ll describe a powerful new complexity-theoretic approach to constructing cryptographic primitives. This approach has already led to multiple long-sought constructions, including public-key encryption with “optimal” security. A key idea is to use “circuit obfuscators” (I’ll explain what these are) to transfer statements from complexity theory to cryptography. No background in cryptography assumed. Based on joint work with Alex Lombardi (https://eprint.iacr.org/2025/1087 [https://urldefense.com/v3/__https:/eprint.iacr.org/2025/1087__;!!NubF!PljU3RkGcYYGarLBYIE29Z4g3rSTyVfH9ItX-XjRMhnJCKKjNHK1Zx4g_yenyfan1sxKzkfIOew1ziWK$]).  Simonyi 101 and Remote Accessa7a99c3d46944b65a08073518d638c23

Upcoming Schedule

Monday, Feb 23, 2026 | 11:00am
Barak Nehoran, Princeton University
Computer Science/Discrete Mathematics Seminar I
Abstract
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Add to calendar Monday, 2026-02-23 11:00Monday, 2026-02-23 12:00America/New_YorkComputer Science/Discrete Mathematics Seminar Iuse-titleSpeakers: Barak Nehoran, Princeton University More: https://www.ias.edu/math/events/computer-sciencediscrete-mathematics-seminar-i-615 Simonyi Hall 101 and Remote Accessa7a99c3d46944b65a08073518d638c23
Tuesday, Feb 24, 2026 | 10:30am
Shashank Srivastava, Institute for Advanced Study
Computer Science/Discrete Mathematics Seminar II
Abstract
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Add to calendar Tuesday, 2026-02-24 10:30Tuesday, 2026-02-24 12:30America/New_YorkComputer Science/Discrete Mathematics Seminar IIuse-titleSpeakers: Shashank Srivastava, Institute for Advanced Study More: https://www.ias.edu/math/events/computer-sciencediscrete-mathematics-seminar-ii-613 Simonyi 101 and Remote Accessa7a99c3d46944b65a08073518d638c23
Monday, Mar 02, 2026 | 11:00am
Yuval Wigderson, ETH Zürich
Color-avoiding Paths
Abstract

The very first result ever proved about tournaments is due to Rédei, who nearly 100 years ago proved that every tournament contains a Hamiltonian directed path. Since then, questions and results about directed paths in tournaments have become a major topic in extremal combinatorics and Ramsey theory.

In this talk, I will discuss some new results on color-avoiding directed paths, that is, directed paths in an edge-colored tournament whose edges all avoid some fixed color. Somewhat surprisingly, such questions turn out to have deep connections to geometric packing, error-correcting codes, k-majority tournaments, Ramsey theory for sequences, extremal problems in convex geometry, Hilbert's inequality, and hypergraph Turán questions, and I will do my best to present (some of) these connections. 

Based on joint work with Jacob Fox and Benny Sudakov.

View additional event details
Add to calendar Monday, 2026-03-02 11:00Monday, 2026-03-02 12:00America/New_YorkComputer Science/Discrete Mathematics Seminar Iuse-titleTopic: Color-avoiding Paths Speakers: Yuval Wigderson, ETH Zürich More: https://www.ias.edu/math/events/computer-sciencediscrete-mathematics-seminar-i-617 The very first result ever proved about tournaments is due to Rédei, who nearly 100 years ago proved that every tournament contains a Hamiltonian directed path. Since then, questions and results about directed paths in tournaments have become a major topic in extremal combinatorics and Ramsey theory. In this talk, I will discuss some new results on color-avoiding directed paths, that is, directed paths in an edge-colored tournament whose edges all avoid some fixed color. Somewhat surprisingly, such questions turn out to have deep connections to geometric packing, error-correcting codes, k-majority tournaments, Ramsey theory for sequences, extremal problems in convex geometry, Hilbert's inequality, and hypergraph Turán questions, and I will do my best to present (some of) these connections.  Based on joint work with Jacob Fox and Benny Sudakov. Simonyi Hall 101 and Remote Accessa7a99c3d46944b65a08073518d638c23
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Past Seminars Archive

Past Seminars Archive

Information About CSDM