Quote from: Carlton Banks on November 10, 2018, 11:48:19 AM

Right, in those days Alan Reiner/etotheipi was pretty active on bitcoin dev mailing lists and places like that, and I'm pretty sure he discussed the ideas with everyone. Was it actually Alan's idea to begin with? I can't remember that exactly.

Alan definitely just went ahead and implemented his design, whereas other wallets took a long time to follow.

Honestly I'm not sure who came up with the idea of HD wallets first. In other ecosystems that require cryptographic material management (think CAs, DNS providers), it is common practice to create one root piece of secure material offline and derive lower schedule keys from that. With this in mind, you can't argue the use of HD wallets in the Bitcoin space is actually a novel invention, as there is prior art in other spheres, even though there was the need for some engineering to suit our use case.

Therefor, with the previous paragraph in mind, while I cannot tell you with certitude who brought the idea of HD wallets to Bitcoin first, I suspect it was floating in many devs mind if not yet in the mailing list, since the practice has been common place in other industries.

The only thing I know for sure is that Armory was the first implementation of this idea in the Bitcoin ecosystem. From what I know, it was ultimately Alan's solo take on the underlying principle. Bitcoin devs with sipa in the lead improved on it to birth BIP32 about a year later (give or take).