It was invented in 2008 and it was appearing in conferences around 2011.
But by summer 2013 , there still had not been one article on the front page about bitcoin. I seem to remember comments on here mostly just deriding it if it was ever mentioned. (Please correct me if I am wrong).
I just feel this is important to share, not even HN knows what a hot technology is, even if it has been in the same room for years. It is interesting and sometimes I wonder what other emergent tech is on the scene which many know little about.