Now that the BlockChain technology is getting more and more attention, I returned to an old lecture I viewed some time ago. For me it has been one of the best sources to understand in depth the inner workings of Blockchain technology and of Bitcoin in specific.
The lecture is:
This is part of the "Bitcoin and Cryptocurrency Technologies Online Course" provided by Princeton University. The full series can be found here: https://www.youtube.com/channel/UCNcSSleedtfyDuhBvOQzFzQ/feed
