As I have said elsewhere (
http://bt.irlbtc.com/view/4793.msg70391#msg70391 ): Great work! :-) I just fear that it might not be able to inspire the kind of fascination that Bitcoin deserves. But that is hard to do, for sure, and I saw in this thread that it is meant to be more of a kickstarter and a more technical video might follow at some point. So that sounds good!
I have been kicking an idea around for a little while on how to explain the technical side of Bitcoin and just wanted to document it here in case someone finds some inspiration in it. I would approach it from the question "What would it take to build a decentralized payment system?" and from there explore the difficulties and Bitcoin's answers to it. I think this way there is a chance for a newcomer to quickly appreciated what all the alien concepts ("block chain") are needed for.
So here is a rough outline following 'Professor Bitcoin' in inventing a payment system:
-- Start of script --
Professor Bitcoin: "Let's invent a payment system today! Moving cash or wealth in general around is part of our everyday live and something we increasingly do online as well. Before we build our own system to do that, let's look at one of our competitors: Paypal. When using Paypal, you give them some of your money and the record it in their books [show some image of a big Paypal book in the center]. Moving your money to someone else who has Paypal is easy now. You can just change the owner in the big Paypal book [animation of a new transaction recorded in the big Paypal book]. So, what's wrong?"
"In a central solution everyone depends on the entity that manages the big transaction book. If they don't like you, they can just freeze your account [animation of entry in the big PayPal book being frozen]. Can we somehow get ride of the need for a big central book?"
"How about this: we just give a copy of the book to every single participant [show animation of the big Paypal book being copied and distributed to a number of participants and the big book itself vanishing] Nice, now everyone has a copy. But how do we make sure they all say the same thing? [let one of the smaller books show the transaction "Mallory to Alice" and another book "Mallory to Bob"]. We no longer have a central authority, so we need a system to keep these records in sync."
"How about some form of voting? Everybody votes on what is the correct version. The one with the most votes wins out, in the hope that honest people hold the most votes. How are votes granted though? It's the Internet, everybody is anonymous and we don't want to ask for IDs. Maybe one vote per IP address? easy to fake. Let's try this: The more CPU power you have, the more votes you get! Maybe not the fairest voting system, but at least everyone can stay anonymous and a supercomputer isn't found at every corner"
"How can we make sure that someone has the computing power they claim? Cryptography to the rescue! Fortunately there are some very hard mathematical problems with just take some time to find the solutions to, even with some of the fastest computers. To vote for a version of the transaction book, you need to spend the time solving these problems [show animation of one version of the transaction book being covered in more and more mathematical formulas until it forms a huge pile; show another version of the transaction book next to it covered in a smaller pile of mathematical formulas]."
"Very good! We have found a way for a number of decentralized and anonymous participants to reach consensus on what is recorded in the transaction book. One last problem remains: how to get money in and out of the system?"
"We can't just let everyone write something in the book - even with the voting in place, nobody could be sure the money is actually there. So we design it as a closed system instead: Those who invest CPU power to keep the voting going and keep everybody honest will occasionally be rewarded with some fresh 'Bitcoins' which they are allowed to record in the book of transactions. To use the Bitcoin system, you either have to invest a lot of CPU power yourself to get some Bitcoins or buy them from other people who are doing so. In effect you pay them for keeping the system going, which is only fair."
-- End of script --
This has some holes, especially the part of what it means to "write in the book" and how you can not just write anything (but only move your own coins around). I'm not sure there is a nice way of explaining that without having to go to deep into public/private key stuff. But still, maybe this approach to explaining it can turn out to be useful.
