Title: Kangaroos, Card Tricks and Discrete Logarithms

Speaker: Steven Galbraith (University of Auckland)

Abstract: The talk will explain the "Kruskal count" card trick and its application to random walk algorithms. I will explain the discrete logarithm problem in a finite group (this is the computational problem: Given g, h in G to find an integer x, if it exists, such that h = g^x) and its applications in cryptography. I will sketch Pollard's Kangaroo algorithm and some subsequent work. The talk will be accessible to a general audience.

Profile: Professor Steven Galbraith has a Bachelor degree from the University of Waikato (NZ), a Master of Science from Georgia Institute of Technology (USA) and a doctorate from Oxford University (UK). He held research positions at Royal Holloway University of London (UK), University of Waterloo (Canada), the Institute for Experimental Mathematics, Essen (Germany) and the University of Bristol (UK). He moved to the University of Auckland in 2009 and is currently the Head of the Mathematics Department.
His research is in computational number theory, computational algebraic geometry and applications in public key cryptography. Currently his main research focus is post-quantum cryptography. He is an international leader in the mathematics of public key cryptography and wrote a large book with this title that was published in 2012 by Cambridge University Press.

This talk is part of the Thematic Program "Isogeny-Based Cryptography", which runs from January 13 to February 28, 2026. The accompanying school on "Introduction to Isogeny-based Cryptography" will be held from February 9-13, 2026.

Language: English

Target audience: General audience/everyone at OIST and beyond.
Freely accessible to all OIST members and guests without registration.

This talk will also be broadcast online via Zoom:
Meeting ID: 946 5822 6839
Passcode: 293486

※ Please note that this event may be recorded and the videos uploaded. In addition, photos may be taken during the event. These are intended for publication online (the OIST website, social media, etc.)※