Comments by "SAL" (@SAL-fs1mr) on "3Blue1Brown" channel.

  1. it is decentralized because the difficulty adjustment rules are performed by (and enforced by) ALL NODES on the network. basically, pretty much anyone, even YOU, can take a regular desktop computer, and start a network full node and start enforcing the protocol rules of bitcoin! (keep in mind that this is different from bitcoin mining).
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  2. Libra is basically just a trusted set of servers - boring!
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  3. Actually that data is not encrypted.
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  4. All network participants (miners and non-miners) are constantly checking to ensure that cannot happen, it violates the protocol rules.
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  5. You can run a network node yourself on your own computer to be sure.
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  6. That could potentially happen, but to me it seems likely that bitcoin would upgrade to a quantum resistant algorithm before it becomes a problem.
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  7. Miners don't have power to forge transactions (even if they all teamed up). Transactions REQUIRE the sender to supply a valid digital signature, miners are simply not able to forge that signature. If they tried, then they will fork themselves into a brand new blockchain that no one else uses (it will be a new blockchain following broken consensus rules). To ensure you stay on the valid blockchain (regardless of what miners try to pull), you should run a full node on your own computer! By running a full node, you are validating all the work the miners do (constantly watching for any rule breaking). Once you keep studying this tech, it should become clear that miners have very limited power to cheat/alter the rules.
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  8. They would not "stop and wait for the next block", they would first verify the mined block (to make sure it follows the consensus rules), then immediately start mining the subsequent block.
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  9. The proof of work blockchain solves the trusted third party problem - instead of trusting a bank or company, you can just look at and verify the blockchain. It isn't necessarily the longest chain that is the correct one - the correct chain is the one with the most cumulative proof of work. basically, by being a peer node on the bitcoin network, it means you are keeping track of the bitcoin blockchain in real time. If another peer node tried to show you a different chain to say "look, this chain is the correct one, trust this instead", your node would instantly know that is incorrect because there is a blockchain that everyone else is using that has more proof of work hashing power behind it.
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  10.  @Jack-sy6di  Bitcoin continuing to run for over 10 years is the proof it actually works. Run a bitcoin network node on your own computer to verify the integrity of the proof of work blockchain (you don't have to trust anyone else's verification). To show it doesn't work, then all you have to do is find a blockchain that has more proof of work mining behind it (good luck with that).
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  11. Banking system without banks that enables global free trade.
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  12. This is the basis for digital security for many things including cryptocurrencies.
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  13. 1. Each individual block contains thousands of transactions. 2. Even if there are no new transactions, the miner could mine an empty block and still earn the new coins reward for that block. 3. The initial interest seemed to be as a digital collectable. These days, people are buying bitcoin because they believe it could serve as a better long term store of value over dollars and there are people all over the world who are using bitcoin as a means of bypassing banks and sanctions (such as in Venezuela for example).
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  14.  @dw61w  that is the double edge sword nature of bitcoin, it is decentralized so it can bypass any censorship, but that means there is no central authority to guarantee a certain value. It is left completely up to the free market to determine what the fair value is, similar to how gold's value is determined. But with regard to being accepted at restaurants, there is a growing number of restaurants that do accept Bitcoin, none I've found that accept gold or elixir.
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  15. The item most used in a barter system becomes the money of the system. Barter systems always transition to a system with currency.
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  16. The system guarantees that conflicting transactions can't occur at the same time time. For example, if A has only 1 bitcoin and made transactions to send 1 bitcoin to B AND 1 bitcoin to C, the system will ensure only one can occur.
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  17. Yes, but realistically it takes a lot of computational power (electricity and expensive computers) to find a valid solution to the next block.
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  18. Hashgraph is a database managed by a few governing nodes. It isn't decentralized.
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  19. Transactions fees are already being paid to the miners.
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  20.  @parthasarathyvenkatadri  for bitcoin transactions today (happening on the bitcoin blockchain), fees are not optional, they are essentially required. Miners already earn about 2% of their income from fees and about 98% from new coins and this will very gradually shift more and more to fees. So when no new coins are left to be mined, mining will continue with miner income coming 100% from fees.
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  21.  @parthasarathyvenkatadri  Well, we can't know for sure until it happens, but bitcoin has a built-in mechanism called the bitcoin mining difficulty adjustment, which should lead to an equilibrium being reached between income from fees and amount of mining power. Just FYI, hosting the blockchain doesn't require any mining. I personally host the copy of the bitcoin blockchain by running a bitcoin network node on this computer.
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  22. You would just have your bitcoin node software connect to one other specific node (of the person you are trying to fool). But it won't really achieve much because the person you are trying to fool is likely connected with other nodes who will be providing them with accurate blocks.
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  23. Not necessarily, miners still have to operate within the rules of the protocol.
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  24. I don't think " fees " is the primary problem Bitcoin is trying to solve. There's ever growing demand for a global transaction system that has no central party control. Miners are not the ones who control the system, it is actually everyone who run network nodes on their computers.
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  25. The hashing operation is a one way function.
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  26. Your method is easily gamed. I could spin up thousands of network nodes (make it look as if they were all different participants) and totally dominate the voting to what I want. To fix that problem, you could have a federation of known nodes, but the question if who gets to choose the federation is a clear point of centralization (for example, XRP has the Ripple company determine who can be validator nodes). Bitcoin solved a this very difficult problem via proof of work, people thought it was unsolvable. Also, when a miner solves proof of work for a block, you don't trust the miner, your node does the checking to ensure the block contents and proof of work are completely valid.
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  27. Each block is broadcast separately, it only needs to include the most recent transactions since the last block!! this is because the transactions in previous blocks have already in broadcast the everyone on the network already has them!!
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  28. Once the sender digitally signs the transaction, that transaction message gets broadcast to the entire network, each node verifying it is correctly signed. If nodes see that it isn't a valid signature, then they don't propagate it. If it is a valid signature, it will then be added to the immutable blockchain by a miner.
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  29.  @ivannovotny7511  All nodes already have all the account balances with associated public ADDRESSES (and addresses can only be derived from an associated public key which must be derived from the private key). So whenever a sender makes a transaction, it is digitally signed with their private key and it will show the public key and show and that it **matches to that specific public address**. So no, an attacker can't alter the transaction without the correct private key - it would be invalid as it won't "match" the public address. The transaction effectively states to the network "this X amount of bitcoin now belongs to this NEW address", and there is no way for an attacker to change it (unless of course they somehow manage to steal your private key and make a transaction before you do). I hope I was able to explain that well enough.
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  30. If you don't learn and understand the basics, then you'll be vulnerable to people scamming you. That is what happens to many people.
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  31. Correct. In Bitcoin, there are 2 sources of rewards that go to pay miners. There is the new coins that get released to the miner who finds a block (this will decrease per block over time, go read about bitcoin "halving"), and the miner also gets all the fees of every transaction they include in a block they mine (which is expected to grow to be worth more than the new coins made in each block).
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  32. An EMP is unlikely to completely wipe out all digital systems the world over. Access to bitcoin is dependent on having the private key, which can be kept on paper. Then when you are able to re-establish digital access, you use your private key to move your bitcoin as you see fit, until then, it stays secured on the blockchain. Bitcoin is a completely peer to peer network, regular computers/laptops run the full network node software, no servers needed at all.
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  33. It is called a nonce, which is basically the special number miners are trying to find to get that small (many leading zeroes) sha256 output. The nonce is very hard to find, but very easy to verify that it meets the criteria to get that sha output.
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  34. All network nodes (whether they are mining or not) have a full copy of the entire blockchain and they all know all the balances of all addresses. Anyone can run a node.
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  35.  @NoTruce  currently, the Bitcoin blockchain is about 250 gigabytes in size, which most laptops can handle without trouble. At maximum capacity, bitcoin will grow at a maximum of 100 gigabytes each year, which would still manageable on home desktop computers over the long term. It is not too hard to get a 10 terabyte hard drive.
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  36. The private key can be used to make a digital signature that proves it corresponds to the public key without the private key being revealed. In other words, very complicated math.
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  37. Yup.
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  38.  @ProvAlex  actually, no. If the sources of renewables are too far away from populated areas, it can't be delivered to people. This is because the typical maximum transmission distance for electricity is about 300 miles.
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  39. Correct, rejected blocks are totally disregarded.
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  40.  Dirk Knight  you are right about nodes not being able to explicitly check for that, but other miners who don't have access to the new mining method will notice how their mining profitability isn't matching their calculations. And with some close scrutiny of the blocks, this is what has lead to finding out that some Chinese bitcoin miners were using a modified mining algorithm called ASICboost.
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  41. Your mom is a smart lady, clearly she wants the best for you! Learn as much as you can!
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  42. It depends. It will initially just sit there "unconfirmed" until it gets mined into the blockchain. Usually no miner will do this for free, so yea, eventually it will just get dropped and doesn't go through. However, if the recipient of that zero fee transaction is serious about wanting that transaction, the recipient can pick up that zero fee transaction and use it in a subsequent transaction (to themselves) that does have a fee (the fee for the subsequent transaction will cover the 2 transactions). This is known as a "child pays for parent (CPFP)" transaction.
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  43. By the time that becomes a reality, bitcoin would have upgraded to a quantum resistant algorithm.
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  44.  @000Dragon50000  bitcoin has done several upgrades already, and there already exists algorithms that are quantum resistant. So why exactly do you think it would not be possible to do?
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  45. You have to account for transaction fees. So if someone wants to send 0.25 bitcoin, they'll instead send 0.251 so that the extra 0.001 goes to the miner who includes the transaction in the next block.
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  46.  @sh-kj2mm  I am a bitcoin user, yes.
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  47. They would know. As soon as a new block is found, all users on the network, including all miners, check to see if every aspect of the block is valid. In bitcoin, you aren't trusting anyone as you are doing all verification on your node on your own computer.
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  48. Potentially could happen in the future, but at that point, Bitcoin would have been upgraded to a quantum resistant algorithm.
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  49. The transaction was digitally signed with Alice's private key, and only Alice's key can sign the transaction she sends. If Bob tries to make a change, it wouldn't be valid - it will simply be ignored by the network.
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  50. Anyone who wants to.
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