
Blockchains from the ground up: Part 1 - mthwsjc_
http://johnmathews.eu/blockchain-introduction.html
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dostovskk
The Minimum Viable Blockchain ([https://www.igvita.com/2014/05/05/minimum-
viable-block-chain...](https://www.igvita.com/2014/05/05/minimum-viable-block-
chain/)) is by far the best introduction to blockchain I have read.

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jcfrei
I always find this introduction (including a "live demonstration") by Anders
Brownworth very illustrative:
[https://anders.com/blockchain/](https://anders.com/blockchain/)

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jfaucett
This is a great video/site. After watching this, it made me think how amazing
the blockchain would be if our accounting and trading systems were built on
top of it. As a programmer outside the financial services sector, it seems to
me something like this has to be the future. But it would be really
interesting to see what quants and others in the field think.

~~~
fergazen
Back in 2008 I invented an algorithm for tree structures where the definition
of the hash of any node, was "the hash of hashes of all its immediate
children". I had invented a way to do 'tree node comparisons' where any time
two tree nodes on a tree had the same 'hash' i knew the content (recursively
deep into the tree) of those nodes was identical. I never went forward on that
algorithm, because i knew it meant each time a tree node was modified, the
hash of all it's parents (i.e. path to root), had to be recalculate. But I had
explained it to several developers who were all amazed by it. It now realize I
had invented blockchain. I am pretty sure i'm not the first one to realize
hashing actual hashes (in a recursive or chained way) is a powerful concept. I
may add this to my current project SubNode (sbnode.com), and I could pivot
that app into a blockchain technology!

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pacaro
I think Merkle got there first, in about 1979 or so.

[https://en.m.wikipedia.org/wiki/Merkle_tree](https://en.m.wikipedia.org/wiki/Merkle_tree)

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fergazen
Very interesting, thanks. I had never heard of Merkle Tree. Since a linked
list is merely a special case of a 'tree structure' (i.e. one where there is
always only one child), we can consider Merkle to be the true 'inventor' of
blockchain. However, really the concept is so simple and obvious that I
wouldn't be surprised if Babbage/Lovelace era folks had written papers on it.

I'm sure there's at least one arse who'll tell me the DIFFERENCE between a
tree and a linked list. lol. Gotta love social media.

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komaromy
He'd also be the true inventor of Git then. It's a widely useful data
structure.

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fergazen
Merkel WAS a genuine innovation, and it DOES collapse into plain blockchain if
all 'nodes' on a given tree have one child, because in this case the directed
graph (tree) is a linked list. If the key innovation in both structures were
not the same then your snarkyness would have been appropriate.

~~~
sbmassey
The point is that there is more to blockchain technology than just Merkle
trees, I think. Just focussing on the underlying datastructure is like saying
filesystems are just B trees or something.

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pacaro
Yes. I think that there a bunch of interesting ideas in blockchain technology,
not all of which are necessarily new, but they are often new to the blog
writer and/or audience. So introductory articles often focus on those basic
concepts, which leads to this confusion

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avenoir
Here is a really great video [1] which really made blockchains click for me. I
believe this was posted on HN a while back.

[1] [https://anders.com/blockchain/](https://anders.com/blockchain/)

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benchaney
This article has a few issues.

First, you spend the first half of the article explaining a signature scheme
that isn't based on cryptography. It isn't really clear what that part of the
article is actually about.

> "Signed by John" <\- John encrypts this line using his private key

This isn't how message signing works. It has all the problems you described in
the first part, before you introduced asymmetric encryption.

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mthwsjc_
Thanks, I corrected the post.

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Niksko
I've found this a really clear and helpful explanation of blockchain concepts
in the past: [http://www.michaelnielsen.org/ddi/how-the-bitcoin-
protocol-a...](http://www.michaelnielsen.org/ddi/how-the-bitcoin-protocol-
actually-works/)

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jkbbwr
One thing that bothers me about all blockchain demos or tutorials is that they
work on the concept of tracking outputs of transactions rather than just
maintaining state.

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webwanderings
Is there a Blockchain email system? Wouldn't that be a solid evolution
forward, in terms of human communication?

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runeks
> Wouldn't that be a solid evolution forward, in terms of human communication?

How so?

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webwanderings
No spam, no solicitation, you know whose line (email) you're picking up, and
whom you're dialing (sending).

