One way to get a verifiable time stamp would be to show knowledge of an unpredictable but well-known thing in the past (providing a lower bound), then to create

One way to get a verifiable time stamp would be to show knowledge of an unpredictable but well-known thing in the past (providing a lower bound), then to create the same thing yourself (providing an upper bound). I wrote about it here: https://news.ycombinator.com/item?id=33558566 https://news.ycombinator.com/item?id=33558566. Your comment in particular made me feel like it was worth posting!