> Toggle pointless gifs off<p>First time I've seen that. That should really be the standard for any author who decides to pepper their articles with 'memes' and other unrelated distractions.<p>Perhaps this is a cultural or generational thing that I am interpreting in the wrong way, but whenever I follow a link to a blog post filled with these kinds of distracting animated pictures I tend to just give up on the article after encountering the first one. I just can't fathom why someone who wishes to inform or enlighten readers on a certain topic feels the need to include a plethora of irrelevant distractions.<p>Nice to have a way to turn them off so I can give the article a chance based on its merits rather than the presence of memes.
The best explanation of blockchain has to be (unsurprisingly) 3Blue1Brown: <a href="https://www.youtube.com/watch?v=bBC-nXj3Ng4" rel="nofollow">https://www.youtube.com/watch?v=bBC-nXj3Ng4</a><p>Would highly recommend watching this video for anyone who hasn't already.
> See how the hash-chaining mechanism of a blockchain means that even a single corrupt or tampered-with block will invalidate the entire chain after it.<p>Is that strictly required to understand that the entire chain is invalidated? Since blocks are in order, if block X's previous hash doesn't check out, can't we just assume that every block thereafter is also invalid? Effectively a fork has happened at X-1 block.<p>I'm guessing there are more dynamics (speed?) that come into this. Maybe the following questions will make it more clear:<p>1. How do the blocks update when there is a change in a past block?<p>2. In the real world, what process does a node use to validate the chain on an ongoing basis?
I always read that crypto currencies will replace money, because they are distributed.<p>But does a blockchain, that is at the core of every(?) crypto currency really scale well?<p>Keeping the whole ledger constantly available seems rather storage and traffic intensive to me.
One thing that never clicked with me before is that the blockchain is really just a historical ledger, its not actually referenced in real time. When you send a transaction out on the network, nobody is actually validating it against the blockchain. Instead every node is expected to process the blockchain to produce a realtime database called the UXTO which provides a fast lookup to tell you if coins can be spent or not. So the blockchain is a history or transactions, while the UXTO is a statement of all current balances.<p>So while the BTC blockchain is 137 GB in size, the UXTO is only 2.7 GB which easily fits in memory.
<i>IEEE Spectrum</i> has a special report about blockchains:<p><a href="https://spectrum.ieee.org/static/special-report-blockchain-world" rel="nofollow">https://spectrum.ieee.org/static/special-report-blockchain-w...</a><p>It goes into permissioned ledgers and smart contracts, among other applications.
Something I noticed, but didn't see in the article (unless I just missed it). In reference to the security part at the end, if the hash only included the previous block's data, and not its previous hash. If you could edit two consecutive blocks you could change, say, block 2's data and block 3's previous hash. Now everything looks fine because this doesn't change block 3's data so block 4's previous hash looks fine and everything looks legit. Seems like a greater concern than breaking the chain because it wouldn't be detected unless you compared two versions of the chain.
this is still my favorite <a href="https://anders.com/blockchain/" rel="nofollow">https://anders.com/blockchain/</a>
Skip this article (which hilariously tries to rename and redefine a hash properties) and play with this instead: <a href="https://anders.com/blockchain/" rel="nofollow">https://anders.com/blockchain/</a>
I just would like to say thanks to the author for spending his time on this article. I found it very well written and I look forward to seeing part 2. I recommend this article to everyone who asks me about the blockchain technology.
Nice.<p>You should probably mention that what you are describing is a variant of a Merkle tree.<p><a href="https://en.wikipedia.org/wiki/Merkle_tree" rel="nofollow">https://en.wikipedia.org/wiki/Merkle_tree</a>
"it's quite customary to represent hashes in hexadecimal notation (that is, using 0-9 and a-z) - that's what we'll use in this article." -- hexadecimal is 0-9 and a-f