[Animats]

From the title, I thought that this was going to be about the lack of lower bounds in cryptography. Factoring is generally thought to be hard, because many smart people have spent many years trying to make it easier. But there's no proof of that. Maybe somebody will make a breakthrough. In the early days of asymmetric crypto, the knapsack function was believed to be hard. Then a fast way to invert it was found.

As far as I know, there's no publicly known one-way cryptographic function for which there's a provable minimum level of effort to invert.

On the hash function front, where the author seems concerned about something, perhaps the lesson is that filling up hash tables to the 90% level before expansion is pushing too hard.[1] At 70% fill, the hash function doesn't have to be near-perfect, just not awful.

[1] http://accidentallyquadratic.tumblr.com/post/153545455987/ru...