BiBa — One Time Signature

You are at a fairground, and there’s a fun challenge. In front of you are five bins, and the challenge is for you to fire a ball at the bins, and where they will fall randomly into one of the bins. If you get two balls in the bin, you will win, but every attempt will cost you $1. The prize money is $4. Is it a good bet?

Okay. You have five bins, and you want to get to the point where one bin has two balls. For this you will have a 1-in-5 probability that any throw of the ball will go into a specific bin. What is the likely number of throws that it will take to win? Well, as a maximum…

--

--

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store
Prof Bill Buchanan OBE

Prof Bill Buchanan OBE

Professor of Cryptography. Serial innovator. Believer in fairness, justice & freedom. Based in Edinburgh. Old World Breaker. New World Creator. Building trust.