I think the problem is that crypto is a devil-in-the-details issue. I'll cast around and see if I can dig up a survey of the general divergences in crypto schem

I think the problem is that crypto is a devil-in-the-details issue. I'll cast around and see if I can dig up a survey of the general divergences in crypto schemes, but one chink in an implementation sinks the ship. Haven't dug into it, but I guess another interesting question would be "Are various crypto solutions using the same underlying base libraries (and versions) or each rewriting their own implementation of a new system?"