texts: bitcoin-qt 0.21.0 in win10 keep hight disk I/O, and GUI not respond

texts:
My OS is win10, and I used to use bitcoin-qt 0.13.0, it was fine but I found it syncs very slow now, so I upgraded bitcoin-qt to 0.21.0.
I feel 0.21.0 syncs much faster, but it always keep high disk reading (about 2M bytes /sec average) even while income network traffic is low (and disk writing is 0).
This is somehow strange, and causes GUI almost not respond. The process is not frozen  or dead locked, the block chain sync is progressing, and my mouse click can get handled in about 2 minutes.
Is there any command line option could prevent bitcoin-qt 0.21.0 from high disk reading?


texts: I changed BCH in my Trezor to BTC using the wallet coin splitting tool and sent it back again to the same wallet using a new BTC receive address rather than another external wallet like eg Electrum using Shapeshift exchange. But the BTC didn't arrive. Have I lost the coins or are they just lurking in cyberspace waiting to be found again ?


texts: why is getdescriptorinfo returning a "function needed" error with a sortedmulti descriptor?

texts:
When trying:

bitcoin-cli getdescriptorinfo "wsh(sortedmulti(2,tpubDFck48zH8ZzteKKZCR9WMVBJwHZayhQmtCDyDRzHsU7VMTwEXohD23h1CBiizKtFtWck2fVegNDRM193nGx3VLs1RTSGNc1iePKpc1JvsS6/*,tpubDEfXroYtWB6rQ1vNuCUAErUJtxSQ6bjxtz63rWWRaByADcudNFtV6HZz5PM7yeXQLG4GWmrdcRkMEGgdXWWu5TyuRpMXURCiwJoGQYH743f/*,tpubDFSz52YB4yCdbgKeLB5BcJfW1f1AzmLcdzB3nGz6Yft2MVHy2rj4uXBFT8d3maYS4rCxjJdBfExJAM9JCjWmYzkJyaLP4Rk8nALDUSfWbT8/*))"

I get:

error code: -5
error message:
A function is needed within P2WSH

What am I doing wrong?


texts: Slow sync running Bitcon full node on Mac Mini OSX

texts:
It is Jul 2018, I need help after several attempts to sync a full node running on a Mac Mini.

I have tried several times and Bitcoin-qt starts pretty well for the initial sync, downloading with progress that ranges from 1% per hour up to 3 % per hour. But when sync goes around 30% (blockchain around 50 GB) sync slows down to 0.2% per hour so it'd take weeks.

HARDWARE:

1.4GHz dual-core Intel Core i5
OSX 10.13.6
500GB (5400-rpm) hard drive
RAM 4GB of 1600MHz LPDDR3 memory
Good internet speed.

SOFTWARE:

Installed Bitcoin Core implementation 0.16
I tried both, installing the .dmg for mac and also tried to homebrew
Both successful in the beginning, and then sync goes down

I get good connections, and I have the port 8333 opened so I have no clue of what is going on, whether it is problem with the hardware (mac works fine) or the implementation.

Actually I have been running Litecoin and Monero nodes in the same hardware, implementing OSX builts and those worked fine, but Bitcion Core doesn't .

I hope someone can help me, if faced the same difficulties with bitcoin.
I really would like to succeed in this and support the network


texts: How to use Signed Hash to Send Coins in bitcoinj

texts:
I am very new to bitcoinj library. I am using 0.14.7 version of bitcoinj and developing my own application in java. I have created a watch-only wallet by using the tPub of the Offline wallet. Upto Receiving payments on watch-only wallet, it is working fine. Now, i have to spend those coins. For that, I have created a transaction and found its transaction Hash.

To sign that transaction Hash with private key, I have followed How to sign raw transaction given a private key and SHA hash (in java) code. and now I am getting the signed hash. Please guide me that how can I use this signed hash to send and broadcast the transaction.?

Your help will be appreciable. Thanks in advance.

The sample code is given below:

// Through this way, I am finding the Transaction Hash.

SendRequest request = SendRequest.to(Address.fromBase58(params,externalAddress), Coin.parseCoin(amount));
request.signInputs = false;
request.tx.getInputs();
request.missingSigsMode = Wallet.MissingSigsMode.USE_DUMMY_SIG;
String hash = request.tx.getHashAsString();

//now using createSignHash method, which is taking transaction hash and signing that with private key and returning the Signed Hex.
System.out.println("Signed Hash : " + createSignHash(hash));


texts: Is it possible to know my ip address by simply connecting to the Bitcoin network?

texts:
It is saying that in order to stay anonymous, it is usefull to use Tor whenever connecting to the Bitcoin network.

How does someone can discover my ip adress if I'm simply connecting
to the bitcoin network through bitcoin-qt without doing any
transaction ? (I assume the IP are display only during bitcoin
transaction)
Let's say the only transaction i'm doing is receiving bitcoin with
bitcoin-qt (not sending) and without using Tor. Does my identity is
also exposed ?


texts: Does Bitcoin RPC API have a realtime websocket?

texts:
I am trying to create some app based on RPC API call from bitcoin core.

I want to make my btc core daemon send a notification whenever a new transaction is observed. Does BTC core RPC API have a websocket interface to make a call when new transaction happens ?


texts: How Do I Redeem Bitcoin for USD Currency?

texts:
What is the step by step process to redeem Bitcoin into USD Currency & what other options do I have?

Is there a so called prepaid credit card I could redeem it for/into so I can use the cash for purchases, goods, services?


texts:
I'm reading about the concept of UTXO. Everywhere I read, it says that a UTXO in an account is indivisible. One analogy said: "It's as if you wanted to make a $5 purchase with a $10 bill. You wouldn't tear the bill in half."

Let's say I have 0.1 BTC as one coin in my wallet and I want to send 0.05 to someone. What I'd do (minus the fees) is send 0.05 to the person and 0.05 coin back to myself, right? That is, it will be marked in the coin's ledger that I and they respectively are assigned that fraction of it. At the moment of the transaction, wouldn't the coin be split?

Also, at the moment of original mining, aren't all new coins worth 1 BTC? If that is that case, they must be split in some way at some point. Otherwise, the amount of bitcoin that people own in the world would all be integers.


texts: Intuition for Simplicity's CheckSigHashAll

texts:
So, I downloaded Simplicity and started a REPL using cabal new-repl Simplicity. Then I enabled type applications using :set -XTypeApplications.

Consider these invocations:

> (pkwCheckSigHashAll @CommitmentRoot @() lib (Schnorr.PubKey True (read "0")) (Schnorr.Sig (read "0") (read "1")))
CommitmentRoot {commitmentRoot = Hash256 {hash256 =
"\CAN\r\201\231\SO0:1\183\130a\DC3m4u!\193\247e\EOT\194nO\US\208\150\&2\182\ACK\203\151>"}}

> (pkwCheckSigHashAll @CommitmentRoot @() lib (Schnorr.PubKey True (read "1")) (Schnorr.Sig (read "0") (read "1")))
CommitmentRoot {commitmentRoot = Hash256 {hash256 =
"\215\222oj\251&\134\SOZ\202@N\161(\185j2\DELt\156\147\136Nz\183\179\EOTH\166\FS\141F"}}

> (pkwCheckSigHashAll @CommitmentRoot @() lib (Schnorr.PubKey True (read "1")) (Schnorr.Sig (read "0") (read "0")))
CommitmentRoot {commitmentRoot = Hash256 {hash256 =
"\215\222oj\251&\134\SOZ\202@N\161(\185j2\DELt\156\147\136Nz\183\179\EOTH\166\FS\141F"}}

If I understand correctly, the commitment root goes into an transaction output. Since the signature shouldn't play a role, the output from Haskell makes sense since I change the sig and it doesn't affect the commitment root. The example above seems consistent with this intuition. Are both my intuition and the example code correct?

Now, I can call the same method with WitnessRoot:

> (pkwCheckSigHashAll @WitnessRoot @() lib (Schnorr.PubKey True (read "0")) (Schnorr.Sig (read "0") (read "0")))
WitnessRoot {witnessRoot = Hash256 {hash256 =
"\185\FS\176\179\b{Xc2\216\n\240\186\205v\208\164NW\\\DLE\193:\ETB\bMO\211\152*I%"}}

> (pkwCheckSigHashAll @WitnessRoot @() lib (Schnorr.PubKey True (read "1")) (Schnorr.Sig (read "0") (read "0")))
WitnessRoot {witnessRoot = Hash256 {hash256 =
"\240h\NUL\188z4\ACK\200\ETX\151\DC1&Y\253\t\152\176P\146\186\137\NAKm!\STX\DC3\182\148\193\246\172O"}}

> (pkwCheckSigHashAll @WitnessRoot @() lib (Schnorr.PubKey True (read "0")) (Schnorr.Sig (read "0") (read "1")))
WitnessRoot {witnessRoot = Hash256 {hash256 =
"\205\DEL\132Q\245\166!\196\178\248\136\194aO\243+\145T\200E\129I#\253F\134\173i\243K\154J"}}

Again, if I understand correctly, the witness root goes into the spending transaction input. It seems like the witness root is affected if I change either signature or public key, which corresponds to my intuition. Simplicity uses BIP-Schnorr which doesn't allow for pubkey recovery. Again, is my intuition consistent with the above code?

I assume these hash values contain mock transaction metadata like nLocktime, embedded in the lib, correct?

Now, let's say I wanted to do a 2-of-2 MAST-based multisig with Simplicity, how would that look like? There must be a way to compose two different calls to CheckSigHashAll. And the spending transaction would surely need to provide a MAST path through the script, how do I pass that to Simplicity? With oooh?


texts: What are the benefits of running a crypto exchange website?

texts:
Getting straight to the question. Say I want to run a cryptocurrency exchange platform where people could come and buy/sell Bitcoin or Altcoin. The way I understood I have to partner up with a Bank in Order to be able to buy coins and have them in my websites depository to sell and even be able to buy from people instantly in exchange for cash. What are the benefits of this? How much profit is in running such a website? Would be that much profit that could convince a Bank to invest in it?

And is there any way that I could run it with less deposit? like taking the money from user and the buy the Coin instantly and send it to them? like, being a middle man.

Bests.


texts: What is "Cash Address" or "CashAddr"? Is that a new Bitcoin Cash address format?


texts: Is there a type of signature that will be valid in a transaction with multiple inputs/outputs that are unknown at the time of signing?

texts:
Alice is the owner of input_a (txid: xxxyyyzzz). Can Alice do a transaction that will entirely spend input_a (txid: xxxyyyzzz) minus fees to Bob (outout_a pkh: 1aaabbbccc) that can later be picked up by someone else and merge it into another transaction that spends 9 other different inputs (input_b, input_c...k) to 9 other different outputs? Alice needs to do the signature without being aware of which the rest 9 inputs / outputs are, nor the signatures for them.

Anyone knows a trick that could make this happen?


texts: In Ethereum smart contracts is it cheaper to keep all the data, or delete old data?

texts:
As I understand, Ethereum smart contracts can store data internally. I am wondering - is it cheaper for a smart contract to keep all of its data forever if it is keeping the data for any length of time, or does deleting unnecessary data from the contract after it has been used better (even though you have to pay for the operations)?

For example, if I have a contract that keeps a record of everyone that triggered it in the last day, does it make sense for me to remove that data the following day when it is no longer needed, or since the storage was already paid for, there is no point in deleting the old data?


texts: I am using linux mint 14 and was in the process of loading block files. I had a power failure and now it tells me failed to read Block. I would delete the blockchain and start over but IDK where to find it. I am not worried about loosing anything. Please help I am frustrated. I tried uninstalling but this did not work. Please be detailed in response I am a noob.


texts: What does the term "Electronic Cash" stand for in computer science lingo?

texts:
Very often in various online discussions, people cite the word "cash" from the Bitcoin whitepaper title as evidence that Bitcoin should be used for everyday transactions.

I've seen mentions that the term "Electronic Cash" as it appears in the whitepaper title has a very specific meaning in the cypherpunk/computer science community. I've tried looking for a definition online, but I couldn't readily find a more elaborate definition of the term.

What is the meaning of "Electronic Cash" in the computer science lingo?


texts: Why maturity rule on coinbase tx requires too many confirmations w.r.t an arbitrary tx?

texts:
For an arbitrary tx, it is often said that 6 confirmations is sufficient. However, maturity rule states that coinbase tx can't be spent until it receives 101 confirmations. Why do we have this disperancy?

Why 6 confirmations on coinbase transaction is not considered as sufficient for example ?


texts: Why were miners still mining BTC at times when BCH was 2-4x more profitable to mine?

texts:
From August 2017 until mid November (prior to BCH's hardfork with the difficulty adjustment algorithm) there have been some occasions (notably end of August, beginning of October and mid November prior to HF) where mining BCH was 2-4x more profitable than mining BTC. See: https://bitinfocharts.com/comparison/mining_profitability-btc-bch.html#1y

You would expect that in such cases, where mining one coin compared to the other is much more profitable, all miners would switch to the more profitable coin. However, this did not happen, even when BCH was 4x more profitable, there was still hashrate on the BTC chain (see: https://bitinfocharts.com/comparison/hashrate-btc-bch.html#1y).

What could be a possible explanation for this? I am looking to hear a miner's perspective on this.

Thanks in advance!


texts: Would it be theoretically possible to make a Cryptocurrency in a scripting language like PHP, Python, or Ruby?

texts: Just wondering if this is even possible.  If so, are there any practical reasons not to?


texts: Does Trezor have any shortfalls security-wise?

texts: Or do you have a recommendation for another cold wallet?


texts: Can Litecoin & Bitcoin have overlapping Transaction Ids (txid)

texts:
Im currently coding my own transaction lookup page for cryptos. Since Litecoin and Bitcoin are so similar to their txid. I wanted to ask if its actually possible that these 2 currencies have overlapping txid's. I know that Bitcoin uses sha256 & Litecoin uses scrypt.
Let me know, im really interested.


texts: How does a node find a transaction in the blockchain?

texts:
If a (light) SPV client asks a full node for the Merkle branch containing a specific transaction (or the value of an address), how does the full node find this transaction (or the UTXOs) in the blockchain?
Does the full node scan linearly through the entire blockchain or is there a faster way to link transactions and blocks?


texts: NBitcoin: Get address out of raw block stream

texts:
OK, I am sure that this is a really dumb, rookie question, so sorry in advance...
I am trying to read through the blockchain and display the receiving address(es) for all transactions in the chain. (Just like Blockchain-Explorer would do.) My library is NBitCoin in C#, so I am not really working through the raw data here. My starting point is the the Hash that is in the output transaction part (TxOut.ScriptPubKey.PaymentScript.Hash). I read in another post that in order to convert that Base160 encoded hash to a BitCoin address I would have to add 00 in front and then do a Base58 encode of the resulting array. So I did that:

Base58Encoding.Encode(ArrayHelpers.ConcatArrays(DoubleZero,TO.ScriptPubKey.PaymentScript.Hash.ToBytes()))

Then I took a sample and compared it with the output blockexplorer.com had for the same transaction, and unfortunately it didn't match. (And yes, I checked the comment made in this question (Deriving the Bitcoin address from the raw block script), my test transaction has a Base160 encoding, so according to my understanding it was sent to an address.
The hash is: caf74d35ff967c946f99588cb03b774350d83331
My generated output is: 13q1EyUVtUfvpixnYkDRoZUsi5ZVi
Blockexplorer.com shows: 16va6NxJrMGe5d2LP6wUzuVnzBBoKQZKom

Just for the sake of it I tried using all the other hashes in that ScriptPubKey block as well, but none yielded the result blockexplorer.com had.
What am I missing here?
thx


texts: I create my own altcoin based on litecoin source version 0.15 . I have any seed seted,but i have in wallet config addnode=ip. Why my wallet don t sync with blockchain ? It sync if i mine.....


texts: Some miners set the nVersion field of the block header to 0x8000004. What were they signalling for? Was this an error?

texts:
Some miners set the nVersion field of the block header to 0x8000004. What were they signalling for? Is this an error? I have been through a lot of the BIP documentations, but cannot seem to find any references for it.
The first one occurred at block height 416,832. The last at block height 455,757.
https://www.blockchain.com/btc/block/416832
https://www.blockchain.com/btc/block/455757


texts: addrindex patch bitcoin core. it does not show unconfirmed tx

texts:
I'd like to ask about addrindex patched bitcoin core by btcdrak. The diff between bitcoin core and the patch is the following.

https://github.com/bitcoin/bitcoin/compare/0.13...btcdrak:addrindex-0.13

My question is that searchrawtransactions RPC command does not retrieve my unconfirmed tx even though addrindex=1 is set and bitcoin-cli getrawmempool retrieve the tx.

The unconfirmed tx is retrieved by getrawmempool.

$ bitcoin-cli getrawmempool | grep 90e225e60dc36f3d323ffcf6897858e056681b8a9e015ee4371558c7b1f0241f
  "90e225e60dc36f3d323ffcf6897858e056681b8a9e015ee4371558c7b1f0241f",

$ bitcoin-cli getrawtransaction 90e225e60dc36f3d323ffcf6897858e056681b8a9e015ee4371558c7b1f0241f
 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

However, searchrawtransactions does not retrieve the tx.

$curl --user 'xxx:xxx' --data-binary '{"jsonrpc":"1.0","id":"curltext","method":"searchrawtransactions","params":["12sWrxRY7E7Nhmuyjbz4TtGE9jRewGqEZD", 1, 0, 100000]}' -H 'content-type:text/plain;' http://127.0.0.1:xxxx | grep 90e225e60dc36f3d323ffcf6897858e056681b8a9e015ee4371558c7b1f0241f

Have you ever seen this issue? I tried it on addrindex version 0.12.1 and 0.13.2.

I'm sure that unconfirmed txes are showed normally before. The recent high mempool size might be the cause.

I already posted this issue on github but I did not get answer for now. I need to fix it as soon as possible. So I posted this question here too. https://github.com/btcdrak/bitcoin/issues/20


texts:
Possible Duplicate:
  How do you obtain bitcoins?

I just want a straightforward answer, I read a few answers but the explanations are convoluted. Where can I buy bitcoins online? Is there a site or sites? Do/can we buy them with a bank card or credit card or directly with my bank account? If not, how the hell am I supposed to get them lol


texts: How to build a web site on which clients can send and receive bitcoins without an account?

texts:
I've been asked to write a gambling website using bitcoins. The gambling part is easy but I found out about bitcoins only yesterday. I've been following the links and reading but I'm buried in technical jargon; like block chain, wallets, mining etc.

I just want to know the following things.

What does the website need to hold bitcoins?
What does the website need to request funds from player?
How to transfer funds from player to website?
What does the website need to give out funds to player?
How to transfer funds from website to player?

I'd like to know the answers to be as specific as possible, even code level.
Oh, a requirement is not need to open an account on my website or using any payment gateway.

Thank you all in advance.
Moe


texts: How did anyone buy bitcoins before exchanges?

texts:
How did the first bitcoins get bought by anyone?

I understand how miners got them, but what did they do with them?


texts: Differences between types of paper wallets at bitaddress.org

texts:
What are the differences between the different types of paper wallets offered at bitaddress.org? I think the same question applies for the paper wallets offered at bitcoinpaperwallet.com.

On bitaddress.org, the options currently include:

Single Wallet
Paper Wallet
Bulk Wallet
Brain Wallet
Vanity Wallet
Split Wallet
Wallet Details


texts: What are the special Ripple accounts ACCOUNT_ZERO, ACCOUNT_ONE, and root account?

texts:
What are the special accounts ACCOUNT_ZERO, ACCOUNT_ONE, and root account? It's not clear from the Ripple wiki what they are meant for. A little explanation would be nice.

What makes these accounts "special?"


texts:
I'm currently working on my bachelor thesis in which I have to analyze which are the scalability issues the bitcoin protocol has and try to see how it react changing different parameters ( for example the block size ecc... ).
I have downloaded the entire blockchain and I'm currently setuping a private regtest network. I also have been asked to try to use the real transactions up to next week, "load" them in my regtest mode and start testing on this environment. Is this possible? I mean, is there a way to import the real bitcoin transactions on the blockchain into a private blockchain? Do you know any other solution/advice that could help me perform this task?
Moreover, if you know any interesting article/paper about scalability and blockchain would be really useful.
Thanks everyone! :)


texts: Will a bitcoin miner work for other currencies?

texts: If I purchase a card (or similar device) that claims to mine Bitcoins at 10 GH/s, will that device also work for other currencies?  That is, would the device also work on a multi-pool for litecoins, dogecoins, etc?


texts:
I have noticed when running lncli closedchannels, that I have some channels that are closed by my node (close_type: local_force_close).

I am quite sure I have not initiated this manually myself. Is there some logic in LND that drops some channels?


texts: How do text, scripts, and other information get embedded inside the blockchain?

texts: Someone recently suggested that scripts could get embedded inside the blockchain and executed independently by designated machines. What exactly can get stored inside the blockchain, and what are the limits? For instance, if someone uses Bitcoin to purchase electronics from an online site, could the review get embedded inside the transaction and be available for all to view (as opposed to controlled by the seller site)?


texts: generating master public key from address

texts: I want to know is it possible to generate master public key from an address? if not, what is needed to generate xpub key?


texts: Can Large Bitcoin Collider break into the wallet which is created by new version of Electrum?

texts:
I have heard that Large Bitcoin Collider can only break into wallets that are created by broken software.
My other question is that it seems the last private key that they found was on 2017-11-15 01:25:58 UTC. Am I right? Does it mean that their project is not successful any more?


texts: what is the most suitable time interval for updating information on a block while mining the block

texts: So, Bitcoin block consists of some static (magic number, version, previous hash...) and dynamic (timestamp, Merkle Root, transaction count and transactions) elements. What I don't understand is if we update active parts, wouldn't we start guessing nonce from the beginning every time and also calculating the new merkle root would be time-consuming for each transaction? I understand that since PoW is memoryless it doesn't effect much if it is updated every seconds or with every transaction but it may be slower to compute new hashes and root. I'm sorry if I'm wrong but, if miners freeze the block at certain time would they have an advantage. I searched a lot, but couldn't find an article or video of what really happens during mining in slo-mo.


texts:
I have a corrupted wallet.dat that is unreadable by pywallet and db5.3-util.
Having a look in the corrupted wallet in a hex editor, its easy to find the plaintext pubkeys.
Is the structure of the dat file such that it is possible to copy/paste sections of the corrupted wallet so that the key is now part of a new wallet file?
edit - it also seems useful to ask if there is any other manual process for key recovery?


texts:
Reading the docs on target:

  The maximum target used by SHA256 mining devices is:

  0x00000000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF

  Because Bitcoin stores the target as a floating-point type, this is truncated:

  0x00000000FFFF0000000000000000000000000000000000000000000000000000

I know that the purpose is to force miners to generate hashes with a value lower than the target. But the docs are vague, why is this truncation required? And then, why truncate after the first four Fs?


texts: Where can I find altcoin inflation rates?

texts:
I know I can use coincap.io and CoinMarketCap to see a lot of good information about altcoin relative values, and cryptocompare has good detailed information, but where can I access inflation rates for each currency?

I could find the info by reading white papers one by one, but I'm sure someone out there has already done this?


texts:
What is in the Bitcoin Core LevelDB dbcache? Is it full records or metadata?
This question was asked on IRC by Anonymous.


texts: Can I look for transaction in the genesis block?

texts:
I'm testing bitcoin and, as an experiment, I added a transaction after the coinbase to the genesis block. However, it appears that it can't be searched with the rpc commands. Why is that?
I already read that the coinbase in the genesis block can't be spent and this is ok, but what about the other transactions?


texts:
Let's say an organization decides to attack bitcoin by launching a 50% attack.

Can someone estimate how big the effort is?

How expensive would such an attack be from scratch (buying enough
ASICs)?
How feasible is it for an organization with a lot of
computers to do it using their existing computational power?

For example, can a company like google do it by, say, turning 5% of their computers towards attacking bitcoin?
Can the US government do it (if they chose)?
Can a few banks group up, buy some equipment and hijack bitcoin this way?

I understand that these are all possible in principle, so I'm looking for back of the envelope estimates of how realistically feasible such scenarios are.


texts: Are there any publications about deanonymizing Bitcoin?

texts:
At the Model United Conference I attend, there is a resolution proposed to de-anonymize BTC in order to cull Darknet transactions.

I know it is impossible but how do i prove it to the other delegates?

Scientific peer-reviewed publications would be amazing.


texts:
How can I setup pushpool on my ubuntu dedi?

I have bitcoind up and running with latest blocks, what's next?


texts: What does it mean when a confirmed transaction gets reversed?

texts:
I am using bitcoin-cli to do verification of transfer. From the wiki, it mentions that a transaction has a higher confidence in confirmation after 6 blocks deep. However, a block that is put into the blockchain should not to be reverted or removed.

So I want to know what will trigger a confirmed transaction to become invalid and what will actually happen to the blocks and the blockchain?

Especially in bitcoin-cli when I get a block with the target transaction, what will happen if this transaction does not get the final confirmation?

Reference: https://en.bitcoin.it/wiki/Confirmation


texts: How to create a transaction without broadcasting

texts: I would like the create a transaction without broadcasting it to the network.


texts: how to double spend Bitcoin transaction?

texts:
How it's possible to double spend a transaction if the transaction outputs are already spent? and why these types of attacks are not preventable?

is it about blockchain sync time between nodes?


texts: How can one unstuck an unconfirmed transaction with Bither?

texts:
I've sent a transaction with the Bither wallet, but accidentally included too little fee. I've since updated my wallet software, so it shouldn't happen again. However, what can I do to speed up the stuck transaction's confirmation or to replace it?

This is a complementary question to Why is my transaction not getting confirmed and what can I do about it? which answers the question's broader implications and proposes mitigation mostly focused on Bitcoin Core.


texts: How to cancel the callback url registered on blockchain.info

texts:
So i was testing the Blockchain receive API, and during the first trial, I had a typo on the callback url.

Does that mean blockchain.info will retry to call that bad url 1000 times before it finally gives up ?

Is there a way to cancel the unwanted callback registered on blockchain.info ?


texts: is every Block of blockchain is connect to each other?

texts: like as we create a new block , so it will connected to existing Blockchain or it will create a new blockchain?


texts: What is xbtc? I saw many articles refered xbtc,just like "btc to xbtc". But there's no material telling what it exactly is.


texts: parsing bitcoin input and output addresses from scripts

texts:
can someone walk me through the process of combining script inputs and outputs to reveal the base58 encoded input and output addresses. take for example, block 728. this has two raw script inputs:

493046022100e26d9ff76a07d68369e5782be3f8532d25ecc8add58ee256da6c550b52e8006b022100b4431f5a9a4dcb51cbdcaae935218c0ae4cfc8aa903fe4e5bac4c208290b7d5d01

and

493046022100a2ab7cdc5b67aca032899ea1b262f6e8181060f5a34ee667a82dac9c7b7db4c3022100911bc945c4b435df8227466433e56899fbb65833e4853683ecaa12ee840d16bf01

the first byte of each (49 hex = 73 dec) is the instruction to push 73 bytes onto the stack. according to the wiki each of these input scripts consists of a signature and a public key.

the raw output script is

76a91412ab8dc588ca9d5787dde7eb29569da63c3a238c88ac

which translates to the instructions

OP_DUP OP_HASH160 OP_PUSHDATA0(20 bytes) 12ab8dc588ca9d5787dde7eb29569da63c3a238c OP_EQUALVERIFY OP_CHECKSIG

so given this information, how can i extract input addresses (as shown in blockexplorer.com)? is this even possible?

1Miuw7ifaTYY5qrzKYFcTDiojSFxRfAqwP and 18KrJNtPVu6LWRNPQReqF29iFm7vDhirMk

and output address

12higDjoCCNXSA95xZMWUdPvXNmkAduhWv


texts: Have there been any articles or presentations about Bitcoins in any influential or respected law-related websites or perhaps interviews with notable lawyers or the like?


texts: How big is the NXT blockchain in disk usage compared to the Bitcoin Blockchain as of June 2014? And rate of increase?

texts: Currently I'm looking for the disk usage size of the NXT and Bitcoin blockchain size as of June 2014 and the current rate of of increase every day/week/year?


texts: Will Electrum mnemonic seeds be forward compatible with all future versions of Electrum?

texts:
If I use the newest version of Electrum (2.6.4) to create a mnemonic seed and the current source code (2.6.4) later becomes unavailable, will I be still able to use a mnemonic seed I create now with all future version of Electrum?

I know that Electrum has changed the type of mnemonic seeds it uses at least once (from 12 to 13 words). Should I be concerned that future updates will eliminate compatibility with current mnemonic seeds?

Are there any advantages of my retaining a copy of Electrum (2.6.4) if my only purpose in doing so is wallet recovery several years from now?


texts: Example of data that is hashed in the merkle tree for a transaction

texts:
So I am reading this (excellent resource) on the Bitcoin merkle tree for a transaction.

  The merkle tree is constructed bottom-up. In the following example, we start with four transactions, A, B, C, and D, which form the leaves of the merkle tree, as shown in Calculating the nodes in a merkle tree. The transactions are not stored in the merkle tree; rather, their data is hashed and the resulting hash is stored in each leaf node as HA, HB, HC, and HD:

HA = SHA256(SHA256(Transaction A))

  Consecutive pairs of leaf nodes are then summarized in a parent node, by concatenating the two hashes and hashing them together. For example, to construct the parent node HAB, the two 32-byte hashes of the children are concatenated to create a 64-byte string. That string is then double-hashed to produce the parent node’s hash:

HAB = SHA256(SHA256(HA + HB))

  The process continues until there is only one node at the top, the node known as the merkle root. That 32-byte hash is stored in the block header and summarizes all the data in all four transactions.

That makes sense, but I have a few questions. First is how the Transaction like Transaction A is hashed, and what is included in a transaction in practice. For example, if it's a JSON object stringified, or a byteArray in JavaScript, or if data must be in a specific format, etc.. I would like to see for example how a record would be hashed, like { a: 'foo', b: 'bar', c: 123, ... } or something like that.

Second is, if this is where the idea of the Patricia Merkle Tree (or perhaps even Merkle DAG, which I have seen somewhere) comes in, to shorten the amount of stuff you have to store in memory because the hashes don't completely overlap and so would have a lot of empty tree nodes.

Finally, what an example set of transactions would look like in a single block where they say on average they have 1900 transactions. This would be a pretty deep merkle tree, and I would like to see what the transactions are actually called and some more info on their data structure. For example, if they go all the way down to the ISA (Instruction Set Architecture) operations, or they are much higher level. That's basically all I'd like to know. I didn't see that in the book linked to above yet, but will take a closer look.


texts: What is the appropriate forum for technical discussions about Ripple?

texts:
Is there a mailing list where software developers and other interested parties can have technical discussions about the Ripple source code and other aspects of the network?

Bitcoin Stack Exchange is more suitable for Q&A, where questions have definite answers.


texts: Can Coinbase Bitcoin network fee really be 50%

texts:
Ive just bough £47.81 of bitcoin.  After fees i'm left with 0.00375837 BTC.
I want to buy another cryptocurrency but the network fee is 0.00186539 so i'm left with only £24.41.

Can this fee be correct?  Thats close to 50%.  Is it the sum im trying to trade?


texts: How can I send bitcoins with Bitcoin-QT using the API?

texts:
I'm making a bitcoin-based online marketplace. I've been reading/studying the Bitcoin API commands, and some of the commands need "unlocked wallet". Does this mean a wallet without a passphrase?
I think it's vital that the wallet be encrypted at all times. Still, if I've understood everything correctly, I need to decrypt the wallet (at least for a while) to be able to send bitcoins to another wallet.
So how should I proceed? If someone on the website wants to take his/her coins on to another wallet, do I need to make it so the API removes the PIN or encryption from the wallet, sends the bitcoins and encrypts it again?
Is it secure to do so?

Oh, and I'm using Bitcoin-QT to handle the coins.


texts: Are "coin mixers" actually a real thing? Can they be trusted?

texts:
Ever since I started hearing about Bitcoin, people have been mentioning "coin mixers" to me, and told me to use them. However, even early on, when they were practically throwing away Bitcoins to the left and to the right for anyone to grab, due to their low market price, these always seemed fishy to me.
I just couldn't trust them, even for small amounts of Bitcoin. Certainly not with all my coins.
Today, I just could never trust such a service to do anything but simply steal my coins and don't do anything besides keeping them.
At the same time, I really want privacy. I've paid such extra margins for all these years for purchasing Bitcoin in a "P2P" manner, but my name/identity is still known by various individuals with whom I have traded or purchased goods from.
When I start my Bitcoin service, I will necessarily have to send some Bitcoin out to customers every now and then. And then it will pick "pieces" from my wallet which are known to be tied to me! And that will violate my privacy. But I can't risk losing them entirely, or pay even more than what I've already lost from paying all these extra costs and not to mention the huge transaction fees that the Bitcoin network itself charges. Extra fees for "mixing" the coins is more or less unthinkable.
Are these really a thing? Or just another scam? How can I trust them? Do you all use them? Why wasn't this feature simply built into Bitcoin and automated?


texts: In the basic Wallet based in QT, How can i get by RPC the stored addresses and labels?

texts: this question is for you to ask about the QT wallet, in the section to send coins, there is an address window, and it has the list of the stored addresses we save along the time. So using RPC, do you know if there is a way to obtain this data from inside? i am not refering myself on creating a new address or getaddresses by account command, i mean all the addresses we save, independently if they are ours or not.


texts: What are some http mining pools out there?

texts: The open source FPGA miner with source available at https://github.com/progranism/Open-Source-FPGA-Bitcoin-Miner does not support stratum, so in order to test it, I need an http pool. Are there any left?


texts: Can I move my BTC back into an exchange and still collect BTG?

texts:
I'm new to all this, I exported my private key from my wallet (Exodus) but I don't know how any of this works.  I'm just confused on how the private key works, wont the key be invalid if my BTC amount changes or if I trade away?  I also heard there isn't replay protection on BTG yet.

Coinomi doesn't support BTG yet like they said they would, where can I collect my BTG?

Thanks for any detailed advice.


texts: Where can I find the core binaries for v.0.1.5 to v.0.3.21?

texts:
I have been looking for core binaries (i.e. win32-setup.exe & win32.zip & macosx.zip) for earlier clients. Any advice on where they are hosted? They have all been removed from SourceForge.

https://satoshi.nakamotoinstitute.org/code/ (Only v.0.1.0 to v.0.1.3)
https://bitcoin.org/en/version-history (Only v.0.3.21 to v.0.20.0)
https://github.com/bitcoin/bitcoin/releases (Only tar.gz, also not accurate)

Any advice appreciated!


texts: Will merged mining mine each chain as efficiently as non-merged mining?

texts:
Let's say I get a hash rate of X when mining either Bitcoin or Namecoin.

When using Merged Mining, will I be able to still do X concurrently on both blockchains, or will I do significantly less than X?

In other words, if I merge-mine other coins, will it hurt my Bitcoin mining rate at all?


texts:
Trying to run the Main file of the wallet template from bitcoinj but JavaFX not found. When I run the main file of the wallettemplate I get multiple errors of javafx packages not found. When I try to run the entire thing I get an error missing a cucumber thing.

All the tutorials are outdated and I have only coded basic stuff.

Has anyone tried to use bitcoinj on intellij and java 10? Thank you.


texts: How are nodes supposed to update their inclusion proofs with Utreexo?

texts:
With Utreexo, full nodes can build and verify blocks without storing the UTXO set. This is done by using proofs that the UTXOs in a transaction are included in the Utreexo accumulator. These proofs are broadcast with the transaction. To update the Utreexo accumulator, the only thing required are the UTXOs to be added, and the inclusion proofs of the now-used outputs to be removed.
However, I don't see anywhere in the paper that describes how unused inclusion proofs are updated in this process. It only mentions that "maintaining and updating proofs of every element in the set incurs no additional computational cost above computing the roots". I would guess that in the process of adding or deleting leaves, every UTXO who's proof changes will be touched, and could therefore be easily extracted simultaneously. Does anyone know more in depth how that process would happen?
Also, bonus question: do other kinds of accumulators (eg RSA accumulators) have a way of keeping proofs up to date like this?


texts: Bitcoin will not open instead I see: error loading blkindex.dat

texts:
I have downloaded it onto my windows pc 3 separate times and each time it goes to start the program it shows the bitcoin wallet "loading addresses", then it's "loading block index" then my computer makes a noise and I receive this: error loading blkindex.dat. I click OK and it disappears with no options on how to fix.

I'm not very computer savvy. Please help.


texts: What prevents miners in a pool from retaining the reward?

texts: From what I understand miners submit their hashes to the pool. What prevents a miner to disengage the pool as soon as she finds the right hash?


texts: Can SegWit block weight be increased without a hard fork?

texts: I know segwit's block weight is 4MB. Can it be increased without a hard fork? If no, was that option even considered, and is it even possible?


texts: How can I list my mined coins using RPC? And spend them?

texts: I've mined a few blocks on a blockchain, and I'm trying to figure how to actually see them. What is the correct RPC command ? I've managed to see all the coinbase transactions thanks to listtransactions, and my getbalance output seems ok, but they don't show up in listreceivedbyaddress nor listreceivedbyaccount.


texts:
Doing a simple Google search shows that there are many places on the Internet that say that they give out free bitcoins. All you need to do is give them your deposit address and confirm that you're not a robot, and boom, free bitcoins!

Do "faucets" like this really work, or are they scammers?

Can a faucet do anything with your deposit address (other than deposit coins in it)?


texts:
I have a high performance Desktop computer with a powerful NVIDIA GPU available.
I wonder if there is some software similar to NiceHash Miner which I can install in Linux to make some little cash while I'm working on the machine doing other things.


texts: Can anyone explain these bandwidth download spikes that are linked to bitcoind?

texts:
I am running bitcoind on a linode.com vps server and they provide some really great graphs to the owner of the account.

I logged in and noticed these spikes the other day: http://i.imgur.com/aWoWfie.png

Every minute that those graphs were being generated, bitcoind was running at about 400MB of memory usage and exactly 10 connections to the Bitcoin network.

Any anyone explain the green download spikes shown in the picture I linked to above?

I am positive that I did not upgrade my system or perform and other downloading during the time frame seen on the graphs.


texts: What Bitcoin Securities / Stock exchanges are around?

texts:
As a historical user of GLBSE I thought the concept was brilliant. Sadly that did not end well but many more have appeared.

https://btct.co/ appears to be the most popular.

Which other stock exchanges are available and what are their advantages & disadvantages?


texts: Say I have a moderate amount of hashing power and I want to maximize my profit by using the pool that would give the best rewards for mining with them, what should I look at when choosing a pool?


texts: Is the Cloudflare proposed ODOH protocol a thing that could improve Bitcoin node privacy?

texts:
Recently Cloudflare proposed an improvement to the DNS over HTTPS protocol called ODOH (Oblivious DNS over HTTPS). It allows separating a DNS server into two parts: the resolver and the proxy that receives DNS requests from an end-user, thus avoiding leaking an IP address to the resolver and an actual query to the proxy server.
When running the Bitcoin node with the onlynet=onion parameter, one has to either leave DNS queries enabled (which could potentially reveal a user is running Bitcoin), either to disable the DNS queries completely (dnsseed=0 and dns=0), and then to seed some good nodes with the addnode= parameter.  Both options aren't perfect.
Does (hypothetically) using the ODOH protocol for the initial node discovery make any sense from the privacy perspective?


texts: Why must be the Merkle Tree a full binary?

texts: Bitcoin uses a Merkle tree with hash functions. I mean I do not get it why there must be a full binary tree? A complete could also be possible?


texts: My Bitcoin transaction remained unconfirmed for 20 days now

texts: I sent a bitcoin transaction from one of my wallets into another wallet meant for trading. Its been 20 days now and the transaction remained unconfirmed. Please I need help because I sent this coin from my blockchain.com wallet. I need step by step assistance on how to use the RBF or CPFP on blockchain.com wallet


texts: cgminer works just fine for BTC but LTC mining won't get temps over 50C

texts:
These are the screenshots. Temp on LTC won't go over 50C although I set it to intensity 12 on my 6770. I get 200Mh/s on BTC and I shouuld be getting 200Kh/s, instead I'm getting 80Kh/s.

http://i.stack.imgur.com/LyUea.jpg

http://i.stack.imgur.com/jCgsA.jpg

What's going on?


texts: How do i get info from Bitcoin QT 0.7 to Bitcoin QT 0.11?

texts: I'm having trouble with Bitcoin QT 0.11 not automatically extracting address info from my Bitcoin QT 0.7. When I try to open my Bitcoin QT wallet it comes up with an error code saying it is to unsafe to continue. How can I get hold of my info from my Bitcoin QT wallet.


texts: Help please.  In 2013 I could not remember my password.  I just recovered my password.  I try to open the same wallet I used before but only get a message from Adobe Reader "unable to open because file is not supported or is damaged".  This happens on all my back-ups also.  What can I do to get in my wallet? Thank you in advance.


texts: Checking the first and last characters of a cryptocurrency address?

texts:
When confirming that an address entered on a site/app is what I expect it to be, I often check the first and last 3-4 characters to see if they match.

Is this practice dangerous? Could an attacker feasibly generate an address that matches at the beginning and end, but is different in the middle?


texts: What financial instruments are under development for Bitcoin?

texts:
I'm thinking here specifically of instruments that take a Bitcoin-like approach to trusted parties, eliminating them wherever possible and typically built with Bitcoin as their platform.  (As opposed to simply having a real-world trusted entity issue a Bitcoin-containing or Bitcoin-related financial instrument in the traditional method).

Financial instruments include things like bonds, stocks, contracts, additional currencies, etc.

For example, I know jgarzik was working on smartcoin for a while (has development stopped?) and there are things like this you can do with coloured coins.  Can anyone offer some insight on what is actually being developed re: these and other approaches, and especially what has reached an implemented, usable level?


texts: How can i know which utxo in my wallet will be sent?

texts:
Assuming that i have several utxos in my wallet.
Can i know which utxos will be sent when i request a transaction?
For example, there are 3 utxos in my wallet: 3 BTC, 5 BTC, 7 BTC.
when i send 1 BTC to someone, which utxo will be spent?

biggest one first
oldest one first
smallest one first (but bigger than sending amount)

Of course it depends on the client program, but I'm curious about how it runs in general.
(What about bitcoin-core or exchanges?)


texts: bitcoin-qt restored wallet.dat all synced closes after correct passphrase "assertion error crypt" HELP

texts:
Installed bitcoin-qt and replaced new wallet.dat with old wallet.dat backup

Opened bitcoin-qt and let it sync and all blocks synced and wallet has correct funds and past transactions.

I Want to send money from this wallet to new wallet not bitcoin-qt.

Bitcoin-qt asks for wallet password to send or recieve bitcoins.

I input correct password, bitcoin-qt closes!

Following error on log = bitcoin-qt: crypter.cpp:189: bool
   CCryptoKeyStore::Unlock(const CKeyingMaterial&): Assertion `false'
   failed

I know the password is the correct one. (Confirmed)

Other passwords give error. I've done -salvagewallet -rescan

Update:
I started bitcoind -daemon and did bitcoin-cli walletpassphrase "pass" 120 and gave me the exact same error as above.

Please help.


texts: How to use blockstream's REST api to retrieve JSON output on an address?

texts:
I have a bitcoin address and I want to get the JSON format of the balance using blockstreams api service.

It's this one: https://github.com/Blockstream/esplora/blob/master/API.md#transaction-format

It's not clear on what I need to put in the URL. I tried:

  https://blockstream.info/address/:bc1xxxxxxx

and it doesn't work.


texts: Which nVersion bit is the "hard fork bit?"

texts:
A 2015 draft BIP suggested using a "hard fork bit":

  The most significant bit in nVersion is defined as the hardfork bit. Currently, blocks with this header bit setting to 1 are invalid, since BIP34 interprets nVersion as a signed number and requires it to be >=2 (with BIP66, >=3). Among the 640 bits in the block header, this is the only one which is fixed and serves no purpose, and therefore the best way to indicate the deployment of a hardfork.

https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2015-July/009576.html

If bit indexes increase from left to right, then I imagine the hard fork bit occupying index 31, marked as * below (nVersion is a 32-bit value).

0                   1                   2                   3
0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1|2|3|4|5|6|7|8|9|0|1
                                                              *

According to the proposal, setting bit 31 of nVersion should cause a block to be rejected as invalid.

BIP-9 places further constraints on the available bits, specifically, bits 0-2 must be set as [0, 0, 1]:

  Blocks in the STARTED state get an nVersion whose bit position bit is set to 1. The top 3 bits of such blocks must be 001, so the range of actually possible nVersion values is [0x20000000...0x3FFFFFFF], inclusive.

https://github.com/bitcoin/bips/blob/master/bip-0009.mediawiki

In addition, BIP-9 arranges version bits in increasing order from right to left. That is, version bit 0 is nVersion bit 31, version bit 1 is nVersion bit 30, and so on.

But if this were the case, then version bit 0 would be off-limits. BIP-9 says nothing about this, and in fact BIP-68 was signaled using version bit 0:

  This BIP is to be deployed by "versionbits" BIP9 using bit 0.

https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki

My questions are simple:

Given my diagram above, which nVersion bit index is the "hard fork bit?"
If I'm correct in my interpretation (I don't believe I am), then how could BIP-68 have been signaled without causing the blocks doing so to be rejected as invalid?

Update: the source of my confusion was thinking that nVersion bit indexing and version bit indexing ran in opposite directions. The don't. To signal readiness for a proposal using version bit 1, for example, nVersion bit 1 is set. BIP-9's rules activate when an nVersion signature is detected. This signature is bits 29-31 set as 1, 0, and 0, respectively. This leaves bit 31 unset.

Peter's answer addresses question (1) above.

As for question (2) BIP-68 signaling didn't cause block rejection because bit 0 was being set, not bit 31.


texts: Bitcoin cli Error: too few parameters OS X Big Sur

texts:
I'm running Bitcoin core,I struggled for bitcoin conf file till I found this and this is what I just have in it
server=1
rpcuser=username
rpcpassword=password
rpcallowip=127.0.0.1
rpcport=1300
I have problem with bitcoin cli. I couldn't find any solution to fix it since I have no idea about coding. This is what I see when I try to run it
"Error: too few parameters [Process completed]"
any idea?
I have been searching for solution! let me know if there is anything missing.


texts: Can full node with only IPv4 connect to another full node with only IPv6?

texts:
As far as I know, IPv4 and IPv6 are two different protocols and direct connection between an IPv4 and IPv6 cannot be established.
If I run a full node with only IPv4, can my node connect to another node with IPv6 only?
If no, why do I sometimes see my node's peers are IPv6?

Likewise, is it true that nodes with IPv6 can only connect to other nodes with IPv6?
Since there are only about 1000+ IPv6 full nodes in the network now, isn't that they have much fewer choices of peers?


texts: How to use the bitcoin client without downloading the blockchain?

texts:
I would like to be able to use the bitcoin python client to be able to do things like sign transactions offline, create transactions, create multisig transactions, etc.

Is there a way to do this without having to download the whole bitcoin blockchain 20 GB?

I don't mind looking up the bitcoin addresses, outputs and such using an external website (e.g., blockchain.org) using some sort of API.

Is the a client that does this?


texts: How much time does it take for a Lightning node to forward an HTLC?

texts: How much time passes between the moment an intermediary node receives an HTLC and the moment it forwards if to the next hop? At least what order of magnitude is it? Is it comparable with network-latency (tens to hundreds of milliseconds)?


texts: "bitaddress.org": It generates a BTC or BCH address?

texts:
(1) Is the address generated by www.bitaddress.org a BTC address? Or BCH address (Bitcoin Cash) ?

(2) Is there a general method to recognize BTC address from BCH address?


texts:
So, MultiBit is not updating the transactions in my wallet, I can see the transactions in the blockchain etc, so the money is there but its just not quite working...

I'm hoping to load that wallet with another client, and have been looking at Electrum.

I read another post on here but it seems to be for an older version and while it tells you how to export keys, which I've done, I can't work out how to import it in to Electrum properly.

Can anyone help me out?


texts: How do i find out what city and whatwas posted with code?

texts: 065e7ad1111963cacd4e2ca978ff57023b8297c123911ffbb8a61011d29d1849 how can I see where that was posted and time


texts: Who controls the Payment Hub in tumblebit?

texts:
Who controls the "Payment Hub" in tumblebit?

Is it another protocol or company or is there something else / someone else involved?


texts: Bitcoin addresses are essentially 160-bit hashes of a 256-bit public key. Huh? How can all possible numbers in 256-bit space be squeezed into 160-bit space? Does that mean any given bitcoin address could be derived from more than just one public key?


texts: Is Bitcoin inherently dependent on electricity?

texts:
Obviously, the computing power necessary to create the blockchain requires access to fast hashing which requires electricity. Given that local power outages do occur, and this can cause a lack of network availability, does this act as the Achilles heel for Bitcoin?

Is it possible to conduct Bitcoin transactions in the absence of electricity?


texts: What's the difference between PoW and PoS?

texts:
I'm looking for an explanation of the difference between Proof of Work algorithm and the Proof of Stake and how they relate to Bitcoin and the Blockchain.

Also looking for a fairly simple, non-technical answer. You can get a little technical but I'm not a dev and have no clue how to code.

Peace and Love,

Krypto Kid


texts: How to compute merkle root without coinbasetxn?

texts: How do you build a merkle root without a coinbase transaction? I compute the merkle root without the coinbase portion and I get a different root then the submitter.


texts: How to send bitcoin programatically using API? Bitcoin Transaction. (Without Setting Node)

texts:
Want to send BTC from one address to another address without using
  JSON-RPC.

Followed and used:

https://bitcore.io/api/
https://www.npmjs.com/package/bitcoin-transaction/v/1.1.1

2nd:bitcoin-transaction Working good for testnet but giving each time new errors for Mainnet.

If anyone knows better way to send BTC, kindly let me know.


texts:
I am writing a study work related to blockchain and the potential in my area of working. Therefore I am now analysing how blockchain works.I have some confusion and hope somebody here can help me with a good source or directly help me to understand it.

I use the bitcoin blockchain as example to explain it.

Person A send Person B xx amount of btc
the transaction is not yet on the blockchain (unconfirmed)
The nodes (miner) verify the transaction mathematically in a block and chain in in the blockchain
TX is confirmed and Person B receives xx amount of btc
-> this I got!

Now every 10min a new block is generated with xx amount of BTC (Based on the algorithmus)

The Blockchain runs with SHA-256, every block has a unique hash so every miner understands where is the current ending of the blockchain.

My problem is to understand/connect those three points, I wanna illustrate it on a timeline.

We have a chain lets say this chain has only 5 blocks. So the miners look for the 6th block. The 5th block has a unique hash so every miner knows where to line up the 6th block.

Then we have a list of unconfirmed transaction, every TX has a little incentive fee for the miners.

The miners work (verify old Tx and search for a new block)
I read that they have to solve mathematical quizzes -> where is the link to a new block then?
Do they create blocks while searching for a new block with btc inside?
-> if a new block is found has this block also Tx inside? Does somebody has a sample on the blockchain?
Do they then use those blocks, add Tx and match it to the blockchain?
How many Tx can go in a block?
Are there also empty blocks?

Sorry if my questions sounds stupid.


texts: Mining pool hashrate effect on a miner's income

texts:
Newbie miners have many misconceptions about how the hashrate of the pool they mine in will affect their mining income.

If a big miner joins the pool there are some unhappy miners who think that now they will get paid less because big miners take a big share of the mined coins, while others are cheering because they think a big miner will help them pull in more coins.

Some miners believe you should pick a big/medium/small pool depending on whether your own hashrate is high or low.

How does pool hashrate actually affect miner income? Assuming the pool is not PPS (fixed pay).


texts: How to sign a transaction using multi signature using bitcoind?

texts:
I created a multisignature address using

bitcoin-cli createmultisig 2 '["04A97B658C114D77DC5F71736AB78FBE408CE632ED1478D7EAA106EEF67C55D58A91C6449DE4858FAF11721E85FE09EC850C6578432EB4BE9A69C76232AC593C3B","04019EF04A316792F0ECBE5AB1718C833C3964DEE3626CFABE19D97745DBCAA5198919081B456E8EEEA5898AFA0E36D5C17AB693A80D728721128ED8C5F38CDBA0","04A04F29F308160E6F945B33D943304B1B471ED8F9EACEEB5412C04E60A0FAB0376871D9D1108948B67CAFBC703E565A18F8351FB8558FD7C7482D7027EECD687C"]'
{
    "address" : "38aNB81yPqNp6X2T3rXYZN8Z3C4pSbqEvs",
    "redeemScript" : "524104a97b658c114d77dc5f71736ab78fbe408ce632ed1478d7eaa106eef67c55d58a91c6449de4858faf11721e85fe09ec850c6578432eb4be9a69c76232ac593c3b4104019ef04a316792f0ecbe5ab1718c833c3964dee3626cfabe19d97745dbcaa5198919081b456e8eeea5898afa0e36d5c17ab693a80d728721128ed8c5f38cdba04104a04f29f308160e6f945b33d943304b1b471ed8f9eaceeb5412c04e60a0fab0376871d9d1108948b67cafbc703e565a18f8351fb8558fd7c7482d7027eecd687c53ae"
}

Now my address is : 38aNB81yPqNp6X2T3rXYZN8Z3C4pSbqEvs.

I have to send some coins to another address with my address ( created using multisignature). To create a transaction, I have to sign with atleast 2 private keys. Could anyone explain how to do that?


texts: How to reduce Proof of Work in bitcoind?

texts:
I am trying to create a new genesis block. But it is taking too long to compute (still running). How do I reduce ProofOfWork needed ?

Is it this line that I have to modify ?

chainparams.cpp#L117

  bnProofOfWorkLimit = ~arith_uint256(0) >> 32;

and change it to some small value (i.e replace 32 by 16)?

also do I have to change nBits ?

chainparams.cpp#L148

  genesis.nBits    = 0x1d00ffff;


texts:
When the Ripple client starts, it connects to some initial servers.

How does its find the initial list of servers it should connect to?
Is the initial list hardcoded?


texts: Is SegWit activated and when exactly did that happen? I keep getting conflicting information, any help would be much appreciated!


texts: What part of the code is responsible for coinbase payouts?

texts: Looking for the part of the code responsible for doling out coinbase to the miner who solves the puzzle. I'm guessing it's somewhere in src/rpc/mining.cpp, but it's tough to figure out from the code where the payout is happening. Can anyone clear this up?


texts: synchronizing takes weeks and more than 120 gb

texts:
Do I have to download all 120 gb?
I sent myself 100 euro in bitcoin weeks ago. Waited till bitcoin core synchronised to receive them. but it took weeks. And no money in my wallet. And my pc is out of free space.


texts: Has there been any research papers where someone has completed a full security proof model on blockchain / bitcoin ?


texts: How do I get my Bitcoin Cash from my Blockchain.info wallet?

texts: I am pretty much a Bitcoin novice. Bought some a few years ago, they went into my Blockchain.info wallet and I only checked it again a few days ago. It says I can get the same amount of Bitcoin Cash as I had in actual Bitcoins. It's not very clear whether this will do anything to my Bitcoin value or whether it just gives you a load of Bitcoin cash too. I don't want to do anything to risk my Bitcoins obviously. What do I need to do to "download" my Bitcoin Cash to my Bitcoin wallet? Should I send my Bitcoins to a new Blockchain.info wallet to keep them safe while I get the Bitcoin Cash?


texts:
Okay so I understand that bitcoin's price is increasing/decreasing by its utility, its rarity on the market, how it is publicly perceived, innovations, media, investors exc..

My question is, who decides the price of bitcoin? Or any other cryptocurrency? The cryptocurrencies have value because we believe they have values. But who are the we here? Who changes its values hourly sitting in front of a computer?

I am asking, who is the guy  or the group of people who changes the number that's on this link ?

Also this comes with further questions. The people who decide value of the currency can also try to manipulate it(increase/decrease) by their own interests right? For example if they have tons of bitcoins sitting in their wallet, they will try to increase its value so that they benefit economically. I mean, who would not do that?


texts: Bitcoin sent, confirmed on my end - never received on the other end

texts:
I made a purchase and paid using bitcoin.  They sent me a link which took me to a coinbase processor.  I got the wallet address and sent the money from my Electrum Wallet.  I have 157 confirmations, Electrum shows it's there and complete, but the receiver says they had never received it.   I have been waiting a day for them to send me the wallet address they use so I can see if I sent it to the correct place.

Someone told me that if BTC is not claimed within 30 days it automatically goes back to where it came from.   I do not know if that is true since someone said: "once it's gone it's gone".  But I got some back that exact way.    I just want to know where it got screwed up.

If I know the money will come back, then I don't care if they help or not.   It's their loss.  I would have used it to pay for my purchase.

So where could the money be if they say they no longer use bitcoin?  isn't it still in that wallet?  They just have to get it right?

I hope this is not too convoluted.


texts: What is the point of a soft fork when it's backwards compatible?

texts:
I understand a soft fork occurs when changes in the Bitcoin protocol are backwards compatible, but why is that a fork? Is there really a branch or is that just a formality? Or does this give me a chance to run an older version of Bitcoin (older than the soft fork), and still be part of the system? But, again, why would I do such a thing. For example, is there any active "soft" branches in the network that I can transfer on?
Thank you guys!


texts: How are transactions verified with only the Bitcoin address, not the public key?

texts:
I understand how asymmetric cryptosystems and digital signatures work:

You generate a (private key, public key) pair. You never share the private key, you make the public key ... well, public.
You have a set of functions:

encrypt(public key, plain text) = cipher text
decrypt(private key, cipher text) = plain text
sign(private key, plain text) = signed text
verify_signature(public key, signed text) = is_signature_valid_bool

However, in Bitcoin, the addresses are hashed versions of the public key. There is no way to "undo" the hashing. Hence I'm uncertain how transactions are verified.
I guess the question then is what is actually transferred to whom / stored, when I want to make a transaction. I assumed:

Input Bitcoin addresses
Output Bitcoin addresses
Signature of the transaction with all input address private keys (I guess in order of the inputs)

... but then I don't see how the validation is done. So I assume you sent your public key(s) when you create a transaction. This would explain why you shouldn't use any address again after you spent money from it. The point that confuses me is that I don't see any public keys here
The next unclear thing is the order. Is there an implicit order in which the signatures have to be applied? I assumed this would be done with Script, but I don't see this in the block explorer.
Can somebody shed some light on it?
Non-Answers

How Blockchain transaction verification takes place?: The accepted answer just says "when a node hears about a new transaction, it checks to make sure that the signature is valid". My question is about how this is done without the public key.


texts: interpreting coin base api historical price data


texts: What is the difference between Compact Blocks, Thin Blocks, Xthin and Graphene Compression?

texts:
What is the difference between these block propagation techniques in terms of size / bandwidth & computation requirements and also compatibility & reliability?

All the above techniques try to prevent syncing data which is already available on other clients instead of just syncing the full block mined. However, in my understanding both sender and receiver have to follow some additional logic to result in the same block. Is there any statistic what impact every of the mentioned techniques has, especially when the Mempool is not yet fully synced?


texts:
What is a good strategy for backing up bitcoind's blockchain files (not its wallet file) without having to take (e.g.) a bitcoind that is powering a counterparty-server instance offline?

Copying the blockchain from a running bitcoind may result in a corrupted copy (https://bitcoin.stackexchange.com/a/25260/1660),

To avoid this, is it best to run a separate bitcoind that pulls the blockchain from the first instance (by adding it as its sole network connection using addnode) and periodically stop that then rsync out any changes? Or is there a less circuitous way of getting a coherent blockchain backup from a live bitcoind?


texts: Bitcoin client IRC - a potential network weak link?

texts:
I'm currently learning more and more about the Bitcoin protocol and I`m wondering if using an IRC channel as the source to find your Bitcoin peers is a potential weak link of the Bitcoin network?

From what I understand the channel is hosted on irc.lfnet.org , so if that website was brought down normal clients would be unable to find peers?


texts: What is the store that sells the famous alpaca socks for Bitcoin?

texts: In the now-sort-of-viral Bitcoin video, one notable mention of Bitcoin use was to buy alpaca socks. What is the store that sells or used to sell those iconic socks for Bitcoin?


texts: How do I open bx-linux-x64-qrcode via the command line on Ubuntu 20.0 in order to get access to the BX command tool

texts:
I have tried for three days now to get access to the BX commands, via the libbitcoin-explorer library. I have gone through various tutorials and have tried the install process and i do have a build-boost file where its supposed to be. While it appears that everything has worked, I still cannot use the bx command tools.
I then tried to download the simple executable file from https://github.com/libbitcoin/libbitcoin-explorer/wiki/Download-BX  but I have no idea how to open the file. It is bx-linux-x64-qrcode. My system cant open it via the files app or ubuntu software and I cant figure out how to interact with this file via the command line either.
Please help.


texts: Why does new block include only parent's block hash instead of hash of it's all previous blocks calculated using e.g. merkle tree algorithm?


texts:
I would like to replicate this derivation of keys.

Chain m
ext pub: xpub661MyMwAqRbcFtXgS5sYJABqqG9YLmC4Q1Rdap9gSE8NqtwybGhePY2gZ29ESFjqJoCu1Rupje8YtGqsefD265TMg7usUDFdp6W1EGMcet8
ext prv: xprv9s21ZrQH143K3QTDL4LXw2F7HEK3wJUD2nW2nRk4stbPy6cq3jPPqjiChkVvvNKmPGJxWUtg6LnF5kejMRNNU3TGtRBeJgk33yuGBxrMPHi

Chain m/0H
ext pub: xpub68Gmy5EdvgibQVfPdqkBBCHxA5htiqg55crXYuXoQRKfDBFA1WEjWgP6LHhwBZeNK1VTsfTFUHCdrfp1bgwQ9xv5ski8PX9rL2dZXvgGDnw
ext prv: xprv9uHRZZhk6KAJC1avXpDAp4MDc3sQKNxDiPvvkX8Br5ngLNv1TxvUxt4cV1rGL5hj6KCesnDYUhd7oWgT11eZG7XnxHrnYeSvkzY7d2bhkJ7

Chain m/0H/1
ext pub: xpub6ASuArnXKPbfEwhqN6e3mwBcDTgzisQN1wXN9BJcM47sSikHjJf3UFHKkNAWbWMiGj7Wf5uMash7SyYq527Hqck2AxYysAA7xmALppuCkwQ
ext prv: xprv9wTYmMFdV23N2TdNG573QoEsfRrWKQgWeibmLntzniatZvR9BmLnvSxqu53Kw1UmYPxLgboyZQaXwTCg8MSY3H2EU4pWcQDnRnrVA1xe8fs

I correctly derived the keys in 0h using the CKDprv function. Here are the steps:

xpriv in m:

0488ade4 xpriv
00 depth
00000000 parent fingerprint
00000000 key index
873dff81c02f525623fd1fe5167eac3a55a049de3d314bb42ee227ffed37d508  Chain Code
00e8f32e723decf4051aefac8e2c93c9c5b214313817cdb01a1494b917c8436b35  Key
e77e9d71 Checksum

CKDprv:
HMAC-SHA512 (873dff81c02f525623fd1fe5167eac3a55a049de3d314bb42ee227ffed37d508 (Parent's chain code); 00e8f32e723decf4051aefac8e2c93c9c5b214313817cdb01a1494b917c8436b3580000000 (Parent's Key + Child'index))

Result (64 bytes + 64 bytes):
04bfb2dd60fa8921c2a4085ec15507a921f49cdc839f27f0f280e9c1495d44b5
47fdacbd0f1097043b78c63c20c34ef4ed9a111d980047ad16282c7ae6236141  (Child's Chain Code)

To find the child's key, I added the first 64 bytes with the parent's key

Now, for the next step, having a non-hardened index, I wanted to use CKDpub.

This is the parent's public key:

0488b21e
01
3442193e
80000000
47fdacbd0f1097043b78c63c20c34ef4ed9a111d980047ad16282c7ae6236141 (Chain code)
035a784662a4a20a65bf6aab9ae98a6c068a81c52e4b032c0fb5400c706cfccc56 (Key)
b8b9c580

In the HMAC-SHA512 operation I pass these parameters as input:
47fdacbd0f1097043b78c63c20c34ef4ed9a111d980047ad16282c7ae6236141
035a784662a4a20a65bf6aab9ae98a6c068a81c52e4b032c0fb5400c706cfccc5600000001

I get this result (64 bytes + 64 bytes):

b7d40c610c146701cdabb2df826716086d591664eb77de90b40c115bb653fb4d
5c8c3990242778e21f3d47c20428181c65de054baba9a156b798c0e85a10d9e4

By checking the chain code that the next key must have, the chain code obtained is wrong.

0488b21e
02
5c1bd648
00000001
**2a7857631386ba23dacac34180dd1983734e444fdbf774041578e9b6adb37c19**
03501e454bf00751f24b1b489aa925215d66af2234e3891c3b21a52bedb3cd711c
6f6e2af7

  What am I doing wrong?


texts: As a solo miner how can I prioritize my own unconfirmed transactions?

texts: Is it possible to prioritize my own unconfirmed transaction through my mining machines without being in a pool? And if its possible how can I do that?


texts: Can you run a bitcoin lightning node on a raspberry pi zero?

texts: Will a bitcoin lightning node run on a raspberry pi zero? Does it have to have the full Bitcoin blockchain synced or can it connect to a remote node? Also what are the minimum requirements to get a lightning node up?


texts: Can a bitcoin transaction get confirmed unexpectedly?

texts:
Let's asume I make a transaction with no fee and doesn't get confirmed after a while (let's say 10 days).

Could it be confirmed after that if for some reason some miner keeps a copy? I don't ask if is likely to happen but if it is posible.


texts: Framework for handling transactions/wallets in multiple altcoins generically

texts:
I'm wondering the framework Poloniex, C-CEX and other bigger exchanges use to handle accounts and transactions for such a high number of cryptocurrencies.

What could I use to generically be able to handle accounts and transactions in as many altcoins as possible?


texts: It seems that I can do sendmany(fromaccount, {address:amount,...}) which can have multiple outputs with one account, and sendtoaddress(bitcoinaddress, amount) can have one output with any amount of accounts. Is there a way to have multiple outputs with any number of accounts? I have small amounts of bitcoins distributed amount different accounts and I would like to put them in one transaction to minimize fees. It's odd that there is no rpc call for such a function, or am I completely missing something? Or is there a work around I can do?


texts:
the last days I have thinking about the bitcoins and the technical issues that can have this currency, I am a computer science guy, with many interest in the global economy.

The first question that I want to ask is about the blockchain, the file that store all the transactions done in the network, the problem is that the current size of this file is about 7 GB, with only 100.000 bitcoin accounts, something insignificant to the global economy, still insignificant for a little country of third world.

What will happen when exists 10 , 100 or worse 1000 million of accounts, what will be the size of the blockchain file?.

If this file grow and grow this is not problem for the current tecnology, is more a problem againts the philosopy of bitcoin, because not all the people could be have the file in their own computers, then in the long run the system will tend to transform in something centralized, where only some organizations or very rich people would have a copy of the blockchain file, and the system will be more susceptible to be shut down if some power entity decides to do that.

What do you think about?, is like I am thinking? or am I missing some one about the design of bitcoin?.

Thank for your answers.


texts:
I'm running Bitcoind 0.17 on a raspberry Pi 3. Everything ran smoothly until I did something wrong (I guess) but can't figure out what happened. Now I got this error. Has someone experience with this one:

2

018-11-23T13:11:47Z Fatal LevelDB error: IO error: /home/bitcoin/.bitcoin/indexes/txindex/105794.ldb: Bad message
2018-11-23T13:11:47Z You can use -debug=leveldb to get more complete diagnostic messages
2018-11-23T13:11:47Z

************************
EXCEPTION: 15dbwrapper_error
Fatal LevelDB error: IO error: /home/bitcoin/.bitcoin/indexes/txindex/105794.ldb: Bad message
bitcoin in txindex

2018-11-23T13:12:48Z

Thanks in advance for helping me out.


texts: Is there a bitcoin market for CPU time / memory space / disk space?

texts:
Bitcoin mining pools are like lending / borrowing cpu time, but it's only for hashing.
Is there something more general; a market where you can lend and borrow cpu time, disk space and so on?


texts: Create a transaction spendable in a specific block height

texts:
I am new in Bitcoin and I try to create an address in Bitcoind and send a transaction that the amount will be spendable in a specific height of the blockchain.

Here is what I have done:

privateKey = 'cS5bZo8D1PBXwLbpGwYpb3CPvev5FYA7zPpftXAc6vzvbXt3aAa4'

absolute_time = 150

addr = getAddressFromPriv(privateKey) #customFunction

seq = Sequence(TYPE_ABSOLUTE_TIMELOCK, absolute_time)

script = Script([seq.for_script(),
                        'OP_CHECKLOCKTIMEVERIFY',
                        'OP_DROP',
                        'OP_DUP',
                        'OP_HASH160',
                        p2pkh_addr.to_hash160(),
                        'OP_EQUALVERIFY',
                        'OP_CHECKSIG'])

addr2 = convertScriptToAddress(script)

Then in bitcoin-cli I use that addr2 to bitcoin-cli sendtoaddress <addr2> 10

However, when I inspect the transaction it says that it is spendable in the current block height. Any idea?


texts:
Maybe this question is utterly stupid, but I just don't get it:
I am doing some POC work to understand the BitCoin network a little better and chose C# and the NBitCoin library as my implementation for it. Now, I was trying to read through the blockchain (with a current version of BitCoinCore installed and running locally on my machine) when I hit an unexpected exception: A transaction hash seems to exist twice in the chain.
The Hash looks like this: d5d27987d2a3dfc724e359870c6644b40e497bdc0589a033220fe15429d88599
I found it once at the Block 14.11.2010 17:59:48
and then again at 14.11.2010 21:04:51
In both cases the entry is the same, a new coin generation transaction.
Looking the hash up at blockexplorer.com I can find it at 14.11.2010 22:04:51 (they use a diffent date format there, I just converted it to match the others in this post.)

What am I doing wrong here? I mean... I guess that duplicate transaction IDs can happen throughout the chain, after all, they are just hashes, but how would I ever match the spending input to one of those if the Hash I am referencing it to is not unique?

I am really confused here right now and would appreciate good insights.


texts: Is it legal to use rented dedicated servers to mine?

texts:
I've got several dedicated servers which I'm renting for about 250 Euros from a big hoster (OVH). These server are used for things like ssh/scp, SVN and Git servers (for private repositories), HTTP proxy, etc.

Nothing shaddy here: just fully legal servers that see little use.

I realize these servers are really not powerful at all and would make terrible miners (at least for all the cryptocurrencies where GPU and ASIC mining is disproportionally powerful compared to CPU mining): that is not the point of my question.

My question is: can you legally use a dedicated server which you fully pay for to mine cryptocurrencies all year long? Basically I realized that the CPUs would be running at full speed and would consume more electricity than the way I use them now.


texts:
I wasn't aware of a private key format, however numerous stackoverflow posts hint towards a formatting of some kind

Format of private key

Which private key format is this?

What encoding or format is the private key in Dumpprivkey?

And looking at iancoleman/bip39's website, indeed the private key changes as you change the coin, implying that there is at least a format that takes into account version bytes.

However, using hdkey in js I am unable to reproduce this format, or even the "32-byte big-endian secret parameter" Pieter Wuille describes in the last example.

var bip39 = require('bip39');
var hdkey = require('hdkey');

const mnemonic = 'thunder purchase pave tower lecture upgrade supreme half kid fitness tray shove'
const seed = bip39.mnemonicToSeed(mnemonic); //creates seed buffer
console.log('mnemonic: ' + mnemonic);

const root = hdkey.fromMasterSeed(seed);
const masterPrivateKey = root.privateKey.toString('hex');

const addrnode = root.derive("m/0'/0");
console.log('addrnodePublicKey: '+ addrnode._publicKey.toString('hex'))
console.log('addernodePrivateKey: ' + addrnode._privateKey.toString('hex'))

What is the detailed private key format? What does it consist of, how do you derive it from a standard private key? What is it used for compared to the unformatted private key?


texts:
Theoretically. This is not a mechanism of any kind of attack, but It's about the "lost" coins. May be. It is just for an educational experiment.

What if someone has the ability to send transactions to the each node's memory pool. He have also the ability to send TCP packets from some list of the internet protocol addresses (65533 IPs against 9686 nodes, for example).

He send  transactions, but R and S in it's signature are not formed by the such way as they can be formed by the real owner of the private key. Each node needs to get unsigned TX hash and then check it's Sig for to confirm the output's amount spending. It will take some time.

Is it a theoretically possible DDoS attack to [any]coin network? Each node need to verify signature and it takes some time. Provided that attacker has the full UTXO set locally on his [XXXX] machine IPs.

Or IPv6 folds this "problem"? Or what is really means "bitcoin full-node"?


texts: Running Bitcoin on command-line-only system

texts: I want to run a Bitcoin client on a command-line-only system (Amazon EC2). Is there some specific command-line parameters I should use in order to run the main client without the GUI, or will it run properly without any parameters? How do I later check the status of the client (check number of connections, balance, etc)?


texts: If Lightning Network takes transactions off Blockchain, would that defeat the whole purpose of having a Blockchain ledger?

texts:
Currently Bitcoin transactions can take around 45 minutes. If everyone in the world uses Bitcoin, computers would have to consume 1000 of terabytes per Hour.
The solution is the Lightning network,  which takes transactions Off the Blockchain and groups many transactions into one.
a) However would taking transactions off the blockchain temporarily, defeat the whole purpose of having ledger transaction?
b) Additionally, can Lightning Network know who owns how many bitcoins with multi transactions off the ledger?


texts:
I have compiled my-newcoin-qt and my-newcoind on different platforms (windows, Linux and Mac), with my coin specification based on litecoin.

When I run my-newcoin-qt at the first time, I get no error but the message:

0 Active Connections

What should I do as the next step? Should I compile seeder software on VPS server?


texts: I plan to buy any FPGA boards, any idea for a good sources of information? and what coin is profitable?

texts: Do you guys know any good source for newbie FPGA miners?


texts: Recovering Blockchaininfo wallet in Electrum wallet

texts:
I have my wallet in blockchaininfo and I did the backup of my 12 words (SEED).

I would like to open this wallet in Electrum, I notice that Electrum allow to recover a wallet using a SEED from another wallet (BIP39 seed).

When I type my seed and I choose the BIP39 option, I can click on next step where I have to choose the type of the addresses on my wallet: legacy (p2pkh); p2psh-segwit (p2wpkh-p2sh); native segwit (p2wpkh). I am not sure what those options mean, so I just choose the default option (native segwit). After this step, I just need to set up a password.

But when I do all these steps, I cannot see any Bitcoins in my Electrum wallet, Am I doing something wrong in the steps or is not possible recovering blockchaininfo wallet on Electrum wallet?


texts: where do the timestamps on blocks come from?

texts:
A stork brings them... or...

One of the basic principles on a dist. system is lack of a global clock.

So how are the timestamps assigned to blocks, by the machine that mines it? Couldn't it just insert a fake one?

On page 7 of the Ethereum whitepaper Vitalik says that the algorithm for checking that a block is valid contains the following check:

Check that the timestamp of the block is greater than that of the [median of the 11 previous blocks] and less than 2 hours into the future

So then this notion of time in BTC is quite fuzzy isn't it?

Is there anything I can read that will tell me the exact time bounds of the BTC system?


texts: I'm making an infographic on Bitcoin. How can I download all Bitcoin transactions to do some analysis?

texts: I would like to do some analysis of Bitcoin transactions in the last 3 months and share my insights by preparing an infographic. What would be the best way to get all Bitcoin transactions in the past 3 months?


texts: I can't remember one of the words in my 24-word mnemonic phrase

texts: I wanted to import my mnemonic phrase to my new phone but I can't remember one of the words being asked that I wrote down. Is there any way to get that one? I remember all the other words.


texts: About a change in 0.8.6 - free transactions with less than 0.01 outputs

texts:
// This code can be removed after enough miners have upgraded to version 0.9.
// Until then, be safe when sending and require a fee if any output
// is less than CENT:
if (nMinFee < nBaseFee && mode == GMF_SEND)
{
    BOOST_FOREACH(const CTxOut& txout, tx.vout)
        if (txout.nValue < CENT)
            nMinFee = nBaseFee;
}

The above if clause was as below:

if (nMinFee < nBaseFee)

Gavin explains this change as:

  Remove the rule that all outputs of free transactions must be greater
  than 0.01 XBT. Dust spam is now taken care of by making dusty outputs non-standard.

I don't see any other code change in the same commit. How is dust spam taken care of? Was it made non-standard in a previous version?


texts: What should I consider when deciding to whether or not to mine?

texts:
I go here
http://www.alloscomp.com/bitcoin/calculator

I put in the amount of hashing power I am willing to purchase, EG: 100 GH/s. It tells me I will make $2,094.25 a month. I am aware that the exchange rate changes, difficulty rate rises. But what prevents me from making at least $1500. They say joining a pool is best, but even if I go it alone, what is the thing that will prevent me from making a reasonable amount of money based off of the information in this calculator. I cant be as simple as buying a miner and letting it run all day.


texts: Is it possible for the government to censor bitcoin by blocking ports?

texts:
I am not very clear about the detailed aspect of the ports.

My concern is, is it possible for the ISPs to block these ports of bitcoin clients and therefore censor bitcoin, even if the internet is available. If they can, how bitcoin solve it. If not, please give me an understandable explanation.


texts: Bitcoin Core 'unable to open file' causes reindexing to fail

texts:
I recently struggled to send bitcoin from my Armory wallet (0.96.5) to another account.  Sending bitcoin did not work because the wallet could not synchronize with the blockchain.  Since Armory relies on the connection managed by the bitcoin core client, bitcoin-qt or bitcoind, it became evident that the failure was caused by the bitcoin core clients (0.17.1). The command ./bitcoin-qt --reindex was issued after Armory was shutdown, but failed repeatedly with entries in debug.log having excerpts such as the following immediately before shutdown:

2019-01-15T23:17:07Z Pre-allocating up to position 0x1000000 in rev01636.dat
2019-01-15T23:17:07Z UpdateTip: new best=0000000000000000001e1db68a762512729668e9dd4c6c06cae346a65618189e height=557921 version=0x20c00000 log2_work=90.224133 tx=371925681 date='2019-01-10T12:31:34Z' progress=0.996972 cache=700.2MiB(5254262txo)
2019-01-15T23:17:07Z UpdateTip: new best=00000000000000000014b6677c848def28a7edef1225b0aa865f96199cb1abd8 height=557922 version=0x20000000 log2_work=90.224157 tx=371928196 date='2019-01-10T12:42:46Z' progress=0.996976 cache=700.3MiB(5254902txo)
2019-01-15T23:17:07Z Imported mempool transactions from disk: 1 succeeded, 0 failed, 0 expired, 0 already there
2019-01-15T23:17:09Z Leaving block file 1636: CBlockFileInfo(blocks=144, size=133976289, heights=557764...558003, time=2019-01-09...2019-01-11)
2019-01-15T23:17:09Z Unable to open file /home/**/.bitcoin/blocks/blk01637.dat
2019-01-15T23:17:09Z Unable to open file /home/**/.bitcoin/blocks/blk01637.dat
2019-01-15T23:17:09Z ERROR: WriteBlockToDisk: OpenBlockFile failed
2019-01-15T23:17:09Z *** Failed to write block
2019-01-15T23:37:10Z socket sending timeout: 1201s
2019-01-15T23:37:10Z socket sending timeout: 1201s
2019-01-15T23:37:10Z socket sending timeout: 1201s
2019-01-15T23:37:10Z socket sending timeout: 1201s
2019-01-15T23:37:10Z socket sending timeout: 1201s
2019-01-15T23:37:10Z socket sending timeout: 1201s
2019-01-15T23:37:10Z socket sending timeout: 1201s
2019-01-15T23:37:10Z socket sending timeout: 1201s
2019-01-15T23:37:10Z socket sending timeout: 1201s
2019-01-15T23:37:10Z socket sending timeout: 1201s
2019-01-15T23:39:47Z ERROR: ProcessNewBlock: AcceptBlock FAILED (AcceptBlock: Failed to find position to write new block to disk (code 0))
2019-01-15T23:39:47Z tor: Thread interrupt
2019-01-15T23:39:47Z Shutdown: In progress...
2019-01-15T23:39:47Z addcon thread exit
2019-01-15T23:39:47Z opencon thread exit
2019-01-15T23:39:47Z torcontrol thread exit
2019-01-15T23:39:47Z net thread exit
2019-01-15T23:39:47Z msghand thread exit
2019-01-15T23:39:47Z scheduler thread interrupt
2019-01-15T23:39:47Z Dumped mempool: 3e-06s to copy, 0.000992s to dump
2019-01-15T23:39:47Z Unable to open file /home/**/.bitcoin/blocks/blk01637.dat
2019-01-15T23:39:55Z Unable to open file /home/**/.bitcoin/blocks/blk01637.dat
2019-01-15T23:39:56Z [default wallet] Releasing wallet
2019-01-15T23:39:56Z Shutdown: done

What can be done when a failure to open a file causes reindexing to fail?


texts:
After I imported keys to the brand new wallet I tried to test that it is imported properly so I ran salvagewallet command to verify my new wallet but got these errors!

2014-08-21 12:17:28 WARNING: CWalletDB::Recover skipping key:
2014-08-21 12:17:28 WARNING: CWalletDB::Recover skipping key: Error reading wallet database: CPubKey/CPrivKey corrupt

Could you please help me to understand/solve this problem?


texts: My question is whether the version 1 of Segwit script will allow you to use version 0 scripts types inside of it. In other words, is version 1 superset of version 0? Please include reasoning behind the design decision.


texts: Why was the BIP33 ("Stratized Nodes") never implemented?

texts: What are the technical reasons that BIP33 was never implemented ?


texts:
After reading the O'Reilly book and perusing online resources, I'm still confused about the value that the actual mathematical mining provides to Network (I understand it does provide value, but not clear how).

It seems like once a miner has verified transactions, the really valuable work for the network has been done. And when it starts hashing to win a competition for 25 btc, it's just playing a game that has the sole purpose of adding currency to the network (which I understand is important, no central govt. etc). I don't see how this hashing to find a value less than the difficulty actually provides a real service to the network such as verifying transactions.

Before I jumped into learning about bitcoin, I just assumed the math problems the miners were solving related to detangling or decrypting transactions, but I see now that's not the case. If the competition was a race to verify transactions, that too would make more sense.

Can anyone explain the value of this mathematical race?


texts: I'm running a Litecoin pool that seems like it might be stuck on a particular block... it's been working fine all along but is currently at like 312% Of Expected Shares, I've checked the cron jobs and they seem to be running fine (none disabled) ... should I take action on this or is it purely a bad luck situation?


texts: Why doesn't Butterfly Labs use their ASIC machines for their own mining process?

texts: Butterfly Labs produces ASIC hardware for bitcoin mining. I guess it is cheap for them to produce a 1500 Ghash/sec machine. They could have many of them for a very reduced price. Why, instead of selling them, do not they use them for their own mining so they get more money?


texts: Is there a user-friendly tool for creating and signing raw transactions?

texts:
The title stands for itself.

The only tool for doing so I know of is the bitcoind daemon, but it is for from user-friendly.

A web-tool in JS would be ideal or a simple CLI tool with clear documentation.


texts: JSON-RPC signrawtransaction returns false when using private keys

texts:
I've been working with BitcoinLib testing various parameters on the signrawtransaction rpc call.

It's been mostly successful, however there seems to be a persisting problem when using only private keys to sign a transaction. (second optional argument of signrawtransaction call). The server replies false and returns the failed hex. I have tested the same transaction on the qt console using the same keys, and it returns true.

The wrapper employs a SignRawTransactionRequest class matching the four arguments of the rpc call.

public SignRawTransactionRequest(String rawTransactionHex)
    {
        RawTransactionHex = rawTransactionHex;
        Inputs = new List<SignRawTransactionInput>();
        PrivateKeys = new List<String>();
        SigHashType = SignRawTransaction.SigHashType.All;
    }

It allows for 'inputs' and 'privatekeys' to be null, following the signrawtransaction syntax, while assuming 'sighashtype=all' unless explicitly specified otherwise.

The implementation also includes a SignRawTransactionInput class corresponding to the first optional argument of the rpc call. ([{"txid":txid,"vout":n, "scriptPubKey":hex, "redeemScript":hex } ,...])

public class SignRawTransactionInput
{
    [JsonProperty(PropertyName = "txid", Order = 0)]
    public String TransactionId { get; set; }

    [JsonProperty(PropertyName = "vout", Order = 1)]
    public Int32 Output { get; set; }

    [JsonProperty(PropertyName = "scriptPubKey", Order = 2)]
    public String ScriptPubKey { get; set; }

    [JsonProperty(PropertyName = "redeemScript", Order = 3)]
    public String RedeemScript { get; set; }
}

The request if fed to the wrapper method RpcServer.SignRawTransaction and returns a SignRawTransactionResponse containing the result and the hex as returned by the server.

public class SignRawTransactionResponse
    {
        public String Hex { get; set; }
        public Boolean Complete { get; set; }
    }

So far, signings using just the hex (no other arguments), inputs, different sighashtypes and various combinations of those have been successful. The server replies TRUE and returns the hex of the signed transaction when called with plain hex

or when called with some arguments

However, it returns false when the second optional argument(list of private keys) is used. It has been tested with one, all, and various combinations of the available private keys of the wallet.

I suspect it might be a JSON error and that the wrapper is not constructing that part of the JSON properly, however that usually leads to a parsing error and not the false reply I get here.

The same combinations return true when signrawtransaction is called from the console.

Any ideas on what might be wrong with the private keys argument?


texts: Pros & Cons of Self Hosting Bitcoin Node vs using a 3rd Party Service?

texts:
We are a medium size company building a blockchain application that requires us to interact with the Bitcoin blockchain (+ several other cryptocurrencies). One option is for us to use a 3rd party service that provides us with a uniform API to interact with the blockchain (some examples are BitPay, BlockCypher, BitGo & CoinPayments). The other option is to self host the blockchain node on our servers and natively interact with the blockchain (no middleman involved).
If we go with 3rd party services there’s usually a monthly fee and/or a small percentage charged for each withdrawal (between 0.25% - 1%). So this would be one big downside of going with a 3rd party service. On the other hand, if we host the blockchain ourselves we would be required to perform ongoing maintenance, server upgrades, implement extra security protocols and so on.
A colleague warned me that for every coin we wish to support, we will be required to hire a dedicated expert developer to maintain each node at a cost of $40,000 per year per node
To be clear, we are not concerned about the initial setup of the nodes as we have expert developers who will assist us with that. Our primary concern is related to the ongoing costs to maintain, upgrade, debug and deal with ongoing security concerns of running a large number of nodes on our own server.
It is cheaper for us to hire a developer who will setup all the nodes on our server vs. paying a monthly fee and/or withdrawal fee. Our only concern is related to the long term maintenance costs associated with self hosting nodes.
Are the concerns of my colleague valid or unfounded? Are there valid reasons to believe we will regret self hosting in the long term due to ongoing maintenance costs? If so, what are some issues that we are overlooking with self hosting?
Thank you
Note:
I did see this SE answer that partially addressees this issue. However, a big part of the answer is focused on the initial setup costs of self hosting:

Using RPC calls to your local bitcoin node requires then some
developer knowledge, or a dev-team. That can add to costs in setting
up your environment

As I stated in my question, this is NOT really a concern for us. Our only concern is related to the ongoing costs of self hosting vs. using 3rd party service.


texts: What does the IRS tax in terms of bitcoin practices

texts:
What of the following do I put on the tax form that I got money from a website for viewing ads, donating money, turning gift cards into bitcoin, buying gold, putting money into a bitcoin savings acount, buying miningsweden mining shares, or handing money to a scammer?
By the way I did not buy any bitcoins from an exchange.


texts: How does Internal Keychain exactly work?

texts:
I understand that an internal keychain is used to receive a change of payment when I pay someone.

For example, I pay $20, but it costs $17, so I get $3.

But what I don't understand is how can there be a change? When I send 1 BTC to someone, how does the receiving end determine that I overpaid by 0.9 BTC and send that back to me?


texts: Is there a list of nodes on Testnet that work like the fallback nodes on the Mainnet? I am trying to test my Bitcoin communication code and I'd like to start with just one IP I can rely to be on and responsive.