The Department of Logic & Philosophy of Science Colloquium Series presents

"Alan Turing and the Applications of Probability to Cryptography"
with Sandy Zabell, Professor of Statistics and Mathematics, Northwestern University

Friday, November 2, 2012
3:00 p.m.
Social Sciences Tower, Room 777 (LPS conference room)

In the years before World War II Bayesian statistics went into eclipse, a casualty of the combined attacks of statisticians such as R. A. Fisher and Jerzy Neyman. During the war itself, however, the brilliant but statistical naif Alan Turing developed de novo a Bayesian approach to cryptananalysis which he then applied to good effect against a number of German encryption systems. The year 2012 is the centenary of the birth of Alan Turing, and as part of the celebrations the British authorities have released materials casting light on Turing's Bayesian approach. In this talk Zabell will discuss how Turing's Bayesian view of inductive inference was reflected in his approach to cryptanalysis, and give an example where his Bayesian methods proved more effective than the orthodox ones more commonly used. Zabell will conclude by discussing the curious career of I. J. Good, initially one of Turing's assistants at Bletchley Park. Good became one of the most influential advocates for Bayesian statistics after the war, although he hid the reasons for his belief in their efficacy for many decades due to their classified origins.

For further information, please contact Patty Jones, patty.jones@uci.edu or 949-824-1520.