This is a new article in a mini-series that started with ‘Old-School’ Merkle Trees Rock and Merkle Trees In Pictures. This one is attempting to show blockchains in pictures. I would also like to thank Ross Pettit and Prasanna Pendse for advice and tweaks for this article :)

Blockchain before the addition of a new entry on the ledger:

Produced by OmniGraffle 7.4.3 2017-09-28 10:33:19 +0000 Canvas 5 Layer 1 most r ecently added


Blockchain after a new entry on the ledger (simple case):

Produced by OmniGraffle 7.4.3 2017-09-28 10:32:46 +0000 Canvas 5 Layer 1 pr eviously the most r ecently added most r ecently added


Not so simple case:

Things get added in fits and starts, though, and entries on the ledger are not as linear as the simple case

Produced by OmniGraffle 7.4.3 2017-09-28 10:35:40 +0000 Canvas 5 Layer 1 pr eviously the most r ecently added most r ecently added


Zoom out a little and it starts to look linear again:

Produced by OmniGraffle 7.4.3 2017-09-28 10:37:44 +0000 Canvas 5 Layer 1


Drilling deeper into the hashes:

Imagine a payload ‘A’ was just JSON like { "x": 123, "y": 456 }. And a hashing function h(A) was just shorthand for the SHA1 hash of that: 7f8a375ffad34cc488a7c7892d1a4bb81c653cbe. With some pseudocode we can illustrate what’s happening as things are added to the ledger.

Produced by OmniGraffle 7.4.3 2017-09-28 11:12:04 +0000 Canvas 5 Layer 1 abc = h( ab + h(C)) a = h(A) ledger item B ab = h( a + h(B)) ledger item C ledger item A

At least, that is what the simple case looks like.



Published

September 28th, 2017
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