Birthday Paradox

M.C Escher inspired birthday balloons overlapping each other paradoxically. Watercolor illustration by Allen West.

M.C. Escher inspired birthday balloon paradox watercolor by Allen West.

A math magician appears before you on the street in a puff of smoke, and he will make you his apprentice if you can but answer one question. You fantasize how you could make your investment portfolio grow if only you knew magic, or how you could star in your own series of blockbuster films–move aside Harry Potter! But before you get carried away, the magician posits his question to you: how many people off of the street do I need to invite to my magic show to have a 50% chance that any two of them celebrate their birthday on the same day? You sweat a little, think a little, then sweat a little more before answering: 183.

You won’t be attending Hogwarts anytime soon, my friend. You’ve been hit by, you’ve been struck by, a Birthday Paradox! Continue reading

Subresource Integrity – The Cyber Defense of 2016 You Haven’t Heard Of

Padlock over circuit board layoutAs we make plans this New Year’s Eve to bid farewell to 2016, we’re continually beleaguered by headlines concerning cyber attacks. The stories range from the latest allegations of Russian malware found on a Vermont utility’s computer, to leaked e-mails ahead of the U.S. Presidential Election, and you could even include Apple’s refusal earlier this year to furnish U.S. Government law enforcement agencies with a backdoor they insisted upon to enable encrypted data access. Cybersecurity must go down as one of the leading themes of 2016, and likely will go on to concern us for years to come.

That’s why we should take a moment to recognize a most important development within the information security community during 2016: the publication of the Subresource Integrity (SRI) recommendation by the W3C. Continue reading