It's quite amazing that most of my peer programmers have a very difficult time overcoming the prejudice against cryptocurrencies. I have no idea where this prejudice comes from, but I know very smart people that can solve the most difficult web scalability problems, but that never once glanced over Satoshi Nakamoto extremely short original paper describing the blockchain.
Seriously, the Bitcoin: A Peer-to-Peer Electronic Cash System paper is so ridiculously small and easy to understand that most computer science students should be able to understand it. So all the smart programmers I know should be able to grasp it in a coffee break. Any average programmer should be able to read and understand this paper in 30 minutes or so.
Sehr gut zusammengefasst, wie Blockchains funktionieren. Alternativ dazu ist auch der Wikipedia Artikel aufschlussreich.