1 2017-12-21 01:06:12 <kamyl> is it feasible to mine BTC on a testnet with a decent CPU/GPU or am I better off asking for some BTC to test lightning network?
  2 2017-12-21 01:15:00 <echeveria> kamyl: post an address.
  3 2017-12-21 01:16:31 <kamyl> echeveria: thanks, I will once I sync, but I actually just learned that I need btcd node to test ln and it's probably offtopic here? I probably came with wrong assumption here, I'll read up a bit more about it.
  4 2017-12-21 01:17:54 <echeveria> kamyl: bitcoind doesn't need to be in sync to create an address. setting up a node would be off topic, but someone will provide you with tBTC if you post an address.
  5 2017-12-21 01:21:57 <kamyl> echeveria: thanks a lot for help, really appreciate it, I will do that once I get the actual VM working
  6 2017-12-21 01:26:58 <needcoinbase90> Hey guys. So, I want to float an idea for a BIP, unless I'm missing something. I proposed a CIP for Counterparty a few months back adding an optional fixed-size payment ID/memo to each transaction, that people could fill with data provided to them by an exchange.
  7 2017-12-21 01:27:24 <needcoinbase90> This allows all their customers to deposit assets into the same exchange address, with customers differentiated by the memo
  8 2017-12-21 01:27:45 <echeveria> why would you want this?
  9 2017-12-21 01:28:07 <needcoinbase90> Exchanges need to have a different deposit address per-customer, and after the deposits enter the address, they need to be consolidated into a single one
 10 2017-12-21 01:28:12 <needcoinbase90> let me find an example for you
 11 2017-12-21 01:28:19 <echeveria> if you have a channel to give somebody an address, you already have a channel to pass memo information. the blockchain is for financial information that's relevant to everybody verifying it, a memo is not relevant.
 12 2017-12-21 01:28:35 <needcoinbase90> https://xchain.io/address/1MBTXDNyYmj38NZbN1ogP1ktjN7TjAJLTJ
 13 2017-12-21 01:28:51 <echeveria> there is no functional difference between many outputs at one P2PKH key, and many outputs at many P2PKH keys. you fundamentally misunderstand how the UTXO model works.
 14 2017-12-21 01:28:57 <needcoinbase90> you see that to maintain a deposit address on an exchange, the exchange needs to perform two transactions for every deposit
 15 2017-12-21 01:29:24 <needcoinbase90> one to move from the customer's individual deposit wallet into the exchange hot wallet
 16 2017-12-21 01:29:32 <needcoinbase90> and one for the eventual withdrawal, when it comes
 17 2017-12-21 01:30:04 <needcoinbase90> Adding a payment ID so that the consolidation tx isn't necessary I believe would reduce the amount of data overhead necessary for exchanges (and thus lower their fees)
 18 2017-12-21 01:30:15 <echeveria> that's an inefficiency caused by poor design on the exchanges part, there's zero need to make multiple transactions, and reusing addresses does not in any way reduce the number or complexity of transactions.
 19 2017-12-21 01:30:59 <echeveria> the blockchain doesn't know, differentiate, or care if an output is sent to a re-used address or a new one. they're identical as far as storage and transactional usage is concerned.
 20 2017-12-21 01:31:16 <needcoinbase90> I'm not sure that thats the issue I'm describing
 21 2017-12-21 01:31:41 <echeveria> yes, it is.
 22 2017-12-21 01:32:03 <needcoinbase90> So, 5 customers deposit 1 coin each into their own individual deposit addresses. two sell, and one person buys 1.5.
 23 2017-12-21 01:32:24 <needcoinbase90> You are saying the exchange can send from two different customer deposit addresses?
 24 2017-12-21 01:32:30 <needcoinbase90> I guess that could work
 25 2017-12-21 01:32:35 <needcoinbase90> I'll need to look at the size of that
 26 2017-12-21 01:32:52 <needcoinbase90> xcp doesnt use a utxo model, so its a bit different
 27 2017-12-21 01:32:55 <echeveria> yes. please read how the UTXO works, you're basing your conclusions on misunderstanding.
 28 2017-12-21 01:32:55 <needcoinbase90> it just uses netting I believe
 29 2017-12-21 01:33:00 <needcoinbase90> Thank you for your time.
 30 2017-12-21 05:40:31 <Caust1c> howdy! technical question for you:  How does a full node verify the utxo that a private key has to spend?  Can someone point me in the right direction for the technical documentation and/or code for this?
 31 2017-12-21 05:41:04 <Caust1c> e.g. what's preventing me from creating a transaction which says "i'm sending N when I only have n" and broadcasting that to the network?
 32 2017-12-21 05:41:55 <Caust1c> Surely the full nodes are aware of the balance corresponding to the public key, but do they keep that in memory or on disk somewhere? or do they have to generate it dynamically for each tx?
 33 2017-12-21 05:45:00 <Caust1c> think I found it: https://github.com/bitcoin/bitcoin/blob/5d132e8b974652d96466a1b73ec1231614719fe2/src/validation.cpp
 34 2017-12-21 06:11:24 <echeveria> Caust1c: they verify the ECDSA signature, you can not forge a signature for a key you don't own.
 35 2017-12-21 06:11:37 <echeveria> Caust1c: the UTXO is stored on disk in leveldb, a key value store.
 36 2017-12-21 06:22:06 <Caust1c> neato.  The key being the publickey?
 37 2017-12-21 06:22:22 <Caust1c> and the value being the list of utxo presumably
 38 2017-12-21 06:27:57 <echeveria> Caust1c: bitcoin outputs are scripts, not public keys. the key is the hash of the transaction that created the output, and the index within that transaction.
 39 2017-12-21 06:34:04 <Caust1c> yep, I just read that with COutPoint and CoinEntry
 40 2017-12-21 06:34:22 <Caust1c> thanks for the help echeveria !
 41 2017-12-21 08:06:18 <ren0v0> Hi, does bitcoin-qt have the payment protocol implemented that Bitpay requires?
 42 2017-12-21 08:08:19 <echeveria> ren0v0: yes, this is bip70. bip70 is not a quality protocol, however.
 43 2017-12-21 08:08:49 <echeveria> it's essentially unused other than bitpay due to enormous complexity, huge number of code dependancies, and general poor utility.
 44 2017-12-21 08:09:20 <ren0v0> any idea if its in this version v0.15.0.0-g3751912e8e   ?
 45 2017-12-21 08:09:31 <echeveria> it's been in there for years.
 46 2017-12-21 08:09:46 <ren0v0> Basically i sent a payment last night for an invoice, plenty of fees, 655 sat/B, and it didn't "clear" on the network like usual
 47 2017-12-21 08:10:02 <echeveria> that's unrelated to bip70.
 48 2017-12-21 08:10:11 <ren0v0> hmm, so this is ok?  https://blog.bitpay.com/payment-protocol/
 49 2017-12-21 08:10:19 <ren0v0> just that it was a recent post i thought it might be something new
 50 2017-12-21 08:10:31 <echeveria> no, bip70 is very old and effectively abandoned.
 51 2017-12-21 08:10:45 <ren0v0> so what is this they are talking about, and does -qt support it ?
 52 2017-12-21 08:11:07 <ren0v0> if i send something from bitpay wallet, it confirms instantly, all of the time
 53 2017-12-21 08:11:10 <echeveria> < echeveria> it's been in there for years.
 54 2017-12-21 08:11:33 <ren0v0> ok, so any ideas what i'm doing wrong then, because i have 3 invoices to pay and this refund just cost me $100
 55 2017-12-21 08:12:01 <echeveria> this is a service question to take up with bitpay, not a development question.
 56 2017-12-21 08:12:26 <ren0v0> maybe, maybe not
 57 2017-12-21 08:12:36 <ren0v0> i made a payment in the same 10minute window from their wallet and it worked fine
 58 2017-12-21 08:12:51 <echeveria> this is a question to take up with bitpay.
 59 2017-12-21 08:13:06 <ren0v0> their wallet worked fine, -qt didn't, so how can they help me ?
 60 2017-12-21 08:13:15 <ren0v0> what should i asked them if -qt guys need more info?
 61 2017-12-21 08:14:14 <echeveria> there's no further way anybody but bitpay can help you.  if they 'refunded' a payment, that's their behaviour not the wallets.
 62 2017-12-21 11:02:03 <JackH> ok too many people talking to me about fee's. what article do we have where both fee's + segwit + lightning + how it actually works is put together? anyone? I am fed up defending the fact that this is how the system is supposed to work
 63 2017-12-21 11:07:08 <JackH> in an easy explained way, the bitcoincore post about segwit benefit is too technical for people
 64 2017-12-21 11:12:18 <Sentineo> JackH: I find this on about lightning easily digestible ... can't address other components (fees, segwit) ... https://letstalkbitcoin.com/blog/post/the-lightning-network-elidhdicacs
 65 2017-12-21 11:18:32 <JackH> hmm yes but I was hoping for a "all-in-one"
 66 2017-12-21 11:18:51 <JackH> why blockchain is slow, why segwit helps, why lightning is a payment layer, step by step
 67 2017-12-21 11:19:08 <JackH> and I cant dump 100 articles on someone
 68 2017-12-21 11:19:27 <Sentineo> sure, in case you find one, let us know :P
 69 2017-12-21 11:19:39 <JackH> lol
 70 2017-12-21 11:19:51 <Sentineo> JackH: ask in #bitcoin as well, lot more users there, who do write such articles
 71 2017-12-21 12:23:50 <DSidH> When creating a transaction by hand, how do I decide the scriptPubKey contents? Do I just look at the first byte of the pubKeyHash and decide that its either P2PKH or P2SH ?
 72 2017-12-21 12:50:57 <wumpus> DSidH: yes, basically there's a mapping from address types to scriptPubKey script templates. See to_scriptpubkey in https://github.com/petertodd/python-bitcoinlib/blob/master/bitcoin/wallet.py#L149 for example.
 73 2017-12-21 13:11:46 <DSidH> wumpus: ty. Needed validation from someone
 74 2017-12-21 14:28:20 <jouke> anyone any idea why sendrawtransaction of https://pastebin.com/sGQzG7r6 this tx results in a: "64: too-long-mempool-chain" error message?
 75 2017-12-21 14:29:24 <jouke> One input is confirmed, other input only has an unconfirmed chain of 1 transaction long.
 76 2017-12-21 14:31:47 <jouke> Only blockcypher and blockexplorer are willing to accept the transaction: https://blockexplorer.com/tx/3e8039607e449d13832ae4687b8400239d0c3dc08bede61b88fe0e1b263f424b
 77 2017-12-21 14:37:17 <cncr04s> core devs need to do something
 78 2017-12-21 14:37:34 <jouke> ancestorsize?
 79 2017-12-21 14:37:38 <cncr04s> can't do business if people can't send tx's
 80 2017-12-21 14:48:56 <molz> cncr04s, offtopic, but that is up entirely to exchanges and users to "do something", not core devs, they have done their part
 81 2017-12-21 14:58:28 <jouke> decendent size too big? (too many wallets spending unconfirmed transactions? :x)
 82 2017-12-21 15:02:17 <jb55> anyone have a list of these bitcoin script optimizations somewhere? or want to help out? https://github.com/jb55/btcs/issues/25
 83 2017-12-21 17:27:11 <rocketmagnet> hi guys
 84 2017-12-21 17:27:52 <rocketmagnet> does someone understand the quandl api from https://blog.quandl.com/api-for-bitcoin-data ? i just want to get the btc in dollar for a certain date/time
 85 2017-12-21 17:28:27 <rocketmagnet> i would really be thankfull if someone can help me out here
 86 2017-12-21 17:29:00 <rocketmagnet> i only found https://coinmarketcap.com/api/ that does it the easy way but they only show current data
 87 2017-12-21 21:38:41 <cluelessperson> https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki
 88 2017-12-21 21:38:53 <cluelessperson> I don't get it, is introducing a new address format really necessary?
 89 2017-12-21 21:41:09 <cluelessperson> So, I want to learn how bitcoin works, ground up
 90 2017-12-21 21:41:15 <cluelessperson> Should I just read all the BIPs in order?
 91 2017-12-21 21:51:18 <cluelessperson> https://github.com/bitcoin/bips/blob/master/bip-0008.mediawiki
 92 2017-12-21 21:51:23 <cluelessperson> "This document specifies an alteration to BIP9"
 93 2017-12-21 21:51:39 <cluelessperson> This is BIP8, how the hell does it refer to something that comes AFTER it?
 94 2017-12-21 21:51:41 <cluelessperson> that makes no sense
 95 2017-12-21 22:24:15 <wumpus> cluelessperson: BIP numbers are not sequential
 96 2017-12-21 22:24:49 <cluelessperson> wumpus: I guess I should ask, what offers a proper roadmap to learn all the technical details?
 97 2017-12-21 22:25:38 <wumpus> cluelessperson: would probably make sense to start with https://bitcoin.org/en/developer-documentation
 98 2017-12-21 22:26:02 <cluelessperson> wumpus: thoughts on the "Mastering Bitcoin" Andreas book on github?
 99 2017-12-21 22:26:05 <wumpus> cluelessperson: and only then BIPs, if you encounter one that you want to know more about
100 2017-12-21 22:26:16 <wumpus> cluelessperson: I'd certainly not recommend reading all the BIPs
101 2017-12-21 22:27:04 <wumpus> cluelessperson: I've heard good things about that one too (never read it though)
102 2017-12-21 22:27:33 <cluelessperson> wumpus: Got it.  I'm developing a roadmap as I figure things out.
103 2017-12-21 22:28:49 <wumpus> reading all BIPs would be the bitcoin equivalent of reading all RFCs to learn how the internet works :)
104 2017-12-21 22:35:25 <cluelessperson> wumpus: Thank you for your help
105 2017-12-21 22:41:25 <meshcollider> cluelessperson: I read mastering bitcoin a while back, it was very good from what I remember, so yep that's a good starting point
106 2017-12-21 22:47:52 <meshcollider> cluelessperson: there are maybe a few key BIPs to read but don't read them all at once lol. Maybe BIP32, 65, 112, 125, 141, 173
107 2017-12-21 22:48:22 <cluelessperson> meshcollider: wumpus  https://clueless.fun/blockchain/bitcoin/learning-bitcoin-1/
108 2017-12-21 22:48:23 <cluelessperson> :)
109 2017-12-21 22:48:31 <meshcollider> Just read others as necessary when you come across topics that you want to dive deeper into (e.g. compact blocks, bloom filters, etc)
110 2017-12-21 22:49:24 <meshcollider> cluelessperson: nice :) could be a good resource for others to follow in your footsteps