Tracking innovation, development and experimentation in information studies and library science and spotting new technologies, trends, fun stuff and much more.
Friday, July 17, 2009
Probability Theory, the Birthday Paradox, Web Security and Free Beer
On the off-chance that the above doesn't make it crystal clear for you, what I am trying to say is the probability that in a set of randomly chosen people some pair of them will have the same birthday. In a group of at least 23 randomly chosen people, there is more than 50% probability that some pair of them will both have been born on the same day. For 57 or more people, the probability is more than 99%, and it reaches 100% when the number of people reaches 366 (by the pigeon hole principle, ignoring leap years). The mathematics behind this problem leads to a well-known cryptographic attack called the birthday attack, often discussed as a potential weakness of the internet's domain-name service system and digital signatures.
Actually, I don't really care about all of that, but was trying to figure the odds of winning a bar bet and a free beer by exploiting the stats.
No comments:
Post a Comment