Blockchain Pixie Dust

...being a place I have put a few discussions, and/or links to interesting articles and resources, about blockchains and what they might or might not be good for. [I'm Jonathan Poritz; if you care, there is a whole lot more information about me on my home page.]

First of all, I should say that while I am quite critical of many proposed blockchain applications, I very much like the technology. I've done research in related areas of computer science. I've taught about blockchains from both a theoretical perspective on cryptography and from a practical perspective as an intricate and fun programming task. I would like nothing more than to teach about blockchains again — and I heartily encourage computer science students to take the class: it is full of useful and intricate ideas and practicalities related to cryptogrphy, PKI, hash functions, networking, data structures, distributed computation, consensus protocols, threat models, ... the goodies go on and on.

Unfortunately, I just don't see how this marvelous piece of computer science is at all the appropriate choice in most of the situations in which it is offered as a transformational new technology.

But I am trying to have an open mind! Please, explain to me where I'm wrong in my critique! Invite me to debate the topic! I promise I will be respectful and consider your answers carefully and without preconceptions (other than those coming from understanding the technicalities rather well).

• Well, first of all there is an article I wrote for Inside Higher Ed on the topic of applications in higher education. Here is a page [on this site] which has the link to the IHE article as well as a useful appendix which I wrote but that IHE didn't publish.
• On the opposite end of the spectrum from the concrete, specific objections I made in that IHE article, here is a page of metaphors which I sometimes use when talking about blockchains. The idea is to give people some intuitive feelings for what blockchains are, or are good for, to compensate for the image from enthusiasts who claim blockchain "dices, slices, and mixes your favorite drinks!"
• Anything Nicholas Weaver has written or said about blockchain and cryptocurrencies is well worth your time. E.g., watch these videos:
  • Blockchains and Cryptocurrencies: Burn It With Fire (Nicholas Weaver) — or here is a nice summary of Weaver's video (by Dan Goodin, titled "Fire (and lots of it): Berkeley researcher on the only way to fix cryptocurrency," in Ars Technica; and here is an annotated slide deck by Weaver himself of his presentation.
  • The Cryptocurrency Fraud in 4 Slides
  • Nicholas Weaver talks about Bitcoin at the Naval Postgraduate School
• Same goes for David Gerard, author of Attack of the 50 Foot Blockchain: Bitcoin, Blockchain, Ethereum & Smart Contracts. In particular, keep an eye on his blockchain blog, it's wonderful.
• Bitcoin and Cryptocurrency Technologies is a wonderful book to learn about the computer science of cryptocurrencies. It is, however, a technical book on that subject: I've used it to teach advanced undergrand and masters computer science students; it is absolutely not intended for the general public.
• Bruce Schneier is one of the [very few] great cryptographers today who also thinks about public policy about IT and security — and writes clearly and understandibly on the subject: he has written a series of books on these topics for a general audience [at least one of which was a New York Times best-seller!]. He wrote an interesting article for WIRED about blockchains recently, being: There's No Good Reason to Trust Blockchain Technology, which only addresses a few of the problems with blockchains ... but with devastating effect!
• ...I'll keep adding to this list, as time permits and when I come across something particularly good.

NOTE: The favicon for this website is a cropped version of a [public domain] image of a beautiful flower by the Dutch painter Pieter van Kouwenhoorn (1599-1654), found at Wikimedia Commons.