> > I'm a bit confused. It's been a long time since I looked at protobuf (and > will have to dig into it soon), but I seem to recall it doesn't have any of > the determinism properties you guys just said. > It's not guaranteed no, which is why we store signed sub-messages as byte arrays instead of typed submessages. In practice though, most implementations do seem to serialise things the same way. I recall Python used to be an odd one out, unsure if it still is. OK, I guess we can boil this down more simply. BIP 70 uses protocol buffers because I designed it and implemented the original prototype (with lots of input from Gavin and an earlier proposal by sipa). I used protocol buffers because, beyond all their nice properties, I used to work at Google and so was very familiar with them.