@dang: The year 2012 in the post title appears to be incorrect. Several slides in the linked-to deck refer to events in 2015, and the deck's filename is slides-djb-20151005-a4.pdf, suggesting that the correct year is 2015.
You are absolutely right, my mistake. I saw "2012" in another submission and didn't care to check myself. I can't edit the title myself, though, so hopefully dang will correct it.