The first time I felt like there was real potential for a blockchain, outside of digital currencies, was with DNS + PKI systems. Pretty much identity for websit

The first time I felt like there was real potential for a blockchain, outside of digital currencies, was with DNS + PKI systems. Pretty much identity for websites. I thought it was a much sexier alternative to the current way DNS works and how certificate authorities work. Now does it scale as well? Does it work well for light clients? And is it the right system when you know people will make mistakes and lose keys?