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A from-scratch tour of Bitcoin in Python

karpathy.github.io

281–290 of 293 posts

Re: A from-scratch tour of Bitcoin in Python

#281

Earlier quoted context omitted.

You are incorrect. Deposits in banks are securities, I suggest you read this section titled "Every security that is issued must be held by someone until it is retired" here: https://www.hussmanfunds.com/comment/mc210614/ Copyright doesn't cover the computer reference machine code number, it covers actual intellectual content. Just like it is not settled whether Ethereum or Bitcoin is a security- thoughts on this can…

We're talking about the law, not some guy's blog. If you believe that bank accounts and Bitcoin are securities under the law, then you are incorrect. It doesn't matter whether some guy calls bank accounts securities on his blog. That doesn't change the law. Saying the law could change is literally always true, it means nothing. Will it change? You could make an argument for Ethereum, and I tend to agree that the comm…

Here is a good article. https://www.investopedia.com/terms/f/financialasset.asp

Bank deposits are financial assets- which gets its value from a contractual right or ownership claim.

When you deposit money in a bank, they lend that money out, they make a return, and in a sane world you would receive interest on that money.

Using this definition of a financial asset, I don't think bitcoin qualifies, it is more of an intangible. It might be a financial asset only if it is held at a custodian.

Congress and the courts decide what a security is, not the SEC. The SEC is the enforcement agency from what I can tell.

Re: A from-scratch tour of Bitcoin in Python

#282

Earlier quoted context omitted.

We're talking about the law, not some guy's blog. If you believe that bank accounts and Bitcoin are securities under the law, then you are incorrect. It doesn't matter whether some guy calls bank accounts securities on his blog. That doesn't change the law. Saying the law could change is literally always true, it means nothing. Will it change? You could make an argument for Ethereum, and I tend to agree that the comm…

Here is a good article. https://www.investopedia.com/terms/f/financialasset.asp Bank deposits are financial assets- which gets its value from a contractual right or ownership claim. When you deposit money in a bank, they lend that money out, they make a return, and in a sane world you would receive interest on that money. Using this definition of a financial asset, I don't think bitcoin qualifies, it is more of an in…

Congress defines a security, and the SEC interprets the definition, and the courts subsequently interpret it if the SEC sues. Congress has made a definition that does not apply to Bitcoin, and the SEC has interpreted the definition to not apply to Bitcoin. It hasn't come up in court, and it won't unless the SEC changes their minds first. But their arguments are sound and it's extremely unlikely that their interpretation could change, or that a court would agree with them if they did change.

It's also unlikely that Congress would change the existing definition to apply to Bitcoin. It's much more likely that they would pass specific regulations for Bitcoin and cryptocurrency.

Re: A from-scratch tour of Bitcoin in Python

#283
post #203
post #60

Earlier quoted context omitted.

No, the hardest way is using pencil and paper to mine a block :) https://gizmodo.com/mining-bitcoin-with-pencil-and-paper-164...

That's basically just a SHA256 hashing on pen and paper, doesn't have much to do with how bitcoin works.

To be fair, performing sha256 hashing is kind of the only work that Bitcoin is doing, from a kilowatt hour’s perspective.

Re: A from-scratch tour of Bitcoin in Python

#284

This is reminds me of Ken Shirriff's 2014 "Bitcoins the Hard Way" blog post that also used Python to build a Bitcoin transaction from scratch: http://www.righto.com/2014/02/bitcoins-hard-way-using-raw-bi... (The subtitle of the blog is "Computer history, restoring vintage computers, IC reverse engineering, and whatever" and it is full of fascinating articles, several of which have been featured here on HN)

> The 'dumbcoin' jupyter notebook is also a good reference: "Dumbcoin - An educational python implementation of a bitcoin-like blockchain" https://nbviewer.jupyter.org/github/julienr/ipynb_playground...

https://github.com/yjjnls/awesome-blockchain#implementation-... and https://github.com/openblockchains/awesome-blockchains#pytho... list a few more ~"blockchain from scratch" [in Python] examples.

... FWIU, Ethereum has the better Python story. There was a reference implementation of Ethereum in Python? https://ethereum.org/en/developers/docs/programming-language...

Re: A from-scratch tour of Bitcoin in Python

#285
post #24

I'm amazed that he has time for this kind of hobby work.

He was doing this kind of hobby work well before. I learnt solving Rubik's cube from his page[0]. [0] http://badmephisto.com

I think I still have my printouts of the PLL algorithms somewhere…

Cool to learn this is the same guy.

Re: A from-scratch tour of Bitcoin in Python

#286
post #244

Earlier quoted context omitted.

I don't understand. How do Bitcoin transfers happen off-chain? Are those Bitcoin transactions that don't actually use the blockchain?

The exchange itself holds a fluctuating amount of Bitcoin and then updates entries in its own database when transfers occur between exchange participants to reflect a change in ownership. These constitute the vast majority of transactions that occur and none of them are recorded to the blockchain.

And the exchange is centralized?

Re: A from-scratch tour of Bitcoin in Python

#287
post #190

Earlier quoted context omitted.

That's just a lab demo of a single system, not the network or even a common node configuration.

Years ago, there was a presentation [1] by Peter Rizun of Bitcoin Unlimited at Stanford that demonstrated ~100TPS on Bitcoin, and the potential for 1000+ TPS if certain bottlenecks were removed. People said the same thing you're saying back then, but it served to motivate the big block community, and now today BSV routinely does 300+ MB blocks (1000+ tps). This Teranode software is the future of BSV and will become t…

That's not the issue. Block size has to be limited to protect decentralization. Decentralization is the only thing that has value in blockchains, otherwise you're better off using centralized databases.

Re: A from-scratch tour of Bitcoin in Python

#288
post #62

If you, like me, were curious about what the secret key 1 is on the mainnet, then here you are: 1 1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH https://www.blockchain.com/btc/address/1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH Some others: 2 1cMh228HTCiwS8ZsaakH8A8wze1JR5ZsP https://www.blockchain.com/btc/address/1cMh228HTCiwS8ZsaakH8A8wze1JR5ZsP 3 1CUNEBjYrCn2y1SdiUMohaKUi4wpP326Lb https://www.blockchain.com/btc/address/1CUNEBjYrCn2y1S…

If you are really curious, all the secrets are out there. https://keys.lol/bitcoin/22486853933768128433444208678976948... Finding one with a balance is the hard part.

I was wondering if monitoring those starter addresses could be lucrative... They've transacted quite a lot

Re: A from-scratch tour of Bitcoin in Python

#289

Implementing things from scratch is probably the ultimate test of thorough understanding. Chapeau! On another note I am amused that Mr. Karphathys name describes exactly what he is doing in his day job.

Sometimes implementing things from scratch is the ultimate proof of thorough misunderstanding.

That's very true, I don't know why you're getting downvoted

Re: A from-scratch tour of Bitcoin in Python

#290

Earlier quoted context omitted.

There's been a history of mathematical information used in cryptography produced by the NSA, for which it's later revealed, they had pre-developed an attack. Example: the s-boxes of DES.

Except NSA strengthened DES against this not-yet-known-to-the-public attack (differential cryptanalysis). https://en.wikipedia.org/wiki/Data_Encryption_Standard#NSA's... https://en.wikipedia.org/wiki/Differential_cryptanalysis#His...

While keeping DES to 56 bits, to keep the attack within reach.
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