texts: How can I create a raw transaction in hex format with Bitcoinj?

texts:
How can I create a raw transaction when I'm given the input scripts, input indexes, input txids, output script, output address and output amount? The method below works but it requires the method Transaction setHash to be public which it is not. Can I get what I want without having to make any changes to Bitcoinj?

    NetworkParameters params = MainNetParams.get();
    Transaction tx = new Transaction(params);
    tx.addOutput(Coin.ZERO, new Script(HEX.decode(outputScript)));
    try {
        Address addr = new Address(params, toAddress);
        tx.addOutput(Coin.valueOf(toAmount), addr);
    } catch (AddressFormatException name) {
        return null;
    }

    Script script = new Script(HEX.decode(inputScript));
    Address addr = new Address(params, script.getPubKeyHash());

    Transaction parentTx = new Transaction(params);
    for (int j = 0; j < inputIndex; j++) {
        parentTx.addOutput(new TransactionOutput(params, parentTx, Coin.ZERO, addr));
    }
    parentTx.addOutput(new TransactionOutput(params, parentTx, Coin.ZERO, addr));
    parentTx.setHash(Sha256Hash.wrap(txid)); // requires setHash method to be public
    try {
        ECKey key = new DumpedPrivateKey(params, privateKey).getKey();
        tx.addSignedInput(parentTx.getOutput(inputIndex), key);
    } catch (AddressFormatException name) {
        return null;
    }
    return HEX.encode(tx.bitcoinSerialize());


texts: What are transactions from and to exchanges wallets?

texts:
I am analyzing bitcoin blockchain data, I have the addresses corresponding to a set of exchanges (extracted from walletexplorer) and I'm looking at the transactions made from and to those addresses.

At the beginning I thought these transactions to exchanges' addresses corresponded to people selling their bitcoins (most probably for USD) when the transaction was made FROM an outside address TO an exchange addresses, or to people buying bitcoins when it was on the opposite direction.

Am I right on this statement? Or am I missing something?


texts:
Is it possible to manually add utxos to the utxo database?

Could this be done by editing the chainstate file?


texts: Transactions that cannot be part of block

texts:
Is it possible to have a "unlucky" transaction that can never be part of block? Meaning grouping it with other transactions never results in a valid block?

[Edit]
By not being in valid block, I meant no valid nonce is found with given target difficulty. It seems mathematically, this is possible and what happens to transaction (if there is no expirey) in this case?


texts: How can one verify the address you are sending BTC to

texts:
I've had an incident with an exchange that provides addresses to deposit BTC funds. For some unknown reason, the exchange is telling me they have never received the funds. I read the address with a QR code reader so, unless there are problem using QR codes everything should be correct. I can see the transaction on the block chain and it has been sitting there for many days now.

Is there some method of verifying the addresses provided by an exchange (or anyone) that the address is theirs and they can confirm it is theirs via some sort of response mechanism to an address verification query on the blockchain prior to sending actual funds? Is this doable using the Sign Message feature?
I've been researching this but don't understand what the Signing address is? Is it my public key or the key derived from my public key? Please point me to the docs that explain this process.

Thanks


texts: Where is the downloaded Ardor blockchain stored on windows and linux?

texts: Where can one find the location of the Ardor blockchain on Windows and Linux?


texts:
I noticed that Electrum seeds are 13 words long if the wallet has been created by Electrum but if I used a random hex string to create the wallet it always was 24 words long.

So before I wrote this question, I wasn't quite sure that I remembered the number of words when using a random hex string correctly. I typed down some 32 hex digits and created the wallet. Note that for this I didn't use a source of randomness. Instead, I just thought of hex digits and typed them in. To my surprise, the seed only was 12 words long. I then sha256summed my desktop wallpaper to get a more random 32 digit hex number and was back to 24 words as a seed just like when I did a few experiments some days ago using xxd in combination with /dev/urandom.

So why the different lengths? Clearly, I'm a very poor source of entropy. So Electrum might have compressed the hex number I gave it down. But why are seeds of wallets generated by Electrum only 13 words long whereas wallets created using random 32 digit hex numbers are 24 words long? Shouldn't Electrum use a good source of entropy? Maybe even /dev/random instead of /dev/urandom xored with some stuff it finds itself and therefore create wallets with a 24 words seed?

I don't even see how 13 words are enough to encode a 32 digit hex number. You'd need to encode 256 bit / 13 = 19.69 bit in every word, so you'd need at least 2^19.69 words = 847'180 words. (If you get a different result, use the exact intermediate result.) The English language has 1'025'110 words which would be enough but that's counting words like "pneumonoultramicroscopicsilicovolcanoconiosis". Electrum only uses very basic English words of which there aren't nearly as many as 847'180.

How does Electrum even create several addresses from a single 32 digit hex number? The wallet import format this website generates if I enter the hash of my wallpaper doesn't match any of the private keys in the Electrum wallet. I'd expect the first private key to be the one generated from the 32 digit hex number I entered and all others to be generated using a deterministic key derivation algorithm.


texts: Is in-person double-spending attacks negligible on bitcoin payments?

texts: If I'm planning to accept in-person payments in a store, is it negligible a double-spending attack or isn't it too hard to do?


texts:
I am running bitcoind version 0.19.0.1 on different cloud providers and it gets very slow at some point. After 300k blocks, CPU drops from ~90% to 5% and network usage drops to a minimum. I've tried in a medium size droplet at Digital Ocean and t2.small on AWS.

In the latter, IO operations in the HDD are at a good throughput. My configuration is by default.


texts: How can transaction fees be explained in a simple way?

texts:
I am reading the book Mastering Bitcoins 2nd Edition by O'Reilly, and it says:

Alice buys a coffee from Bob's Cafe for $1.50, or 0.015 Bitcoin

So Alice pays 0.015 Bitcoin, and Bob gets 0.015 Bitcoin, but there is a transaction fee, paid to the miner.
There are some questions:

Does Alice pay more or does Bob get less?  (the fee has to come from somebody)
The way to calculate the fee seems to be a whole essay. Typically, what kind of percentage can the fee be, if it is a $1.5 coffee, or if somebody sends another person US$1 million dollar worth of Bitcoin, or if it is exchanging Bitcoin for US$1 million? But one person mentioned that it is voluntary (even the link above said the spender "may" include a fee, suggesting they can choose not to), but who would want to pay a fee if they don't have to? I can understand if they send over US$1 million and the fee is $13, then they probably don't mind and "want" to include a fee.
The miner gets the fee -- is that the miner who originally did the mining of the coin, or is it that somehow, the fee (or transaction) gets encrypted and a new miner has to mine it.  It is described as: all the miners compete to find the next new Bitcoin, but there is also Proof of Work (to get a fraction of Bitcoin), but there is no mentioning of the miner getting a transaction fee. How does it factor into the flow or procedure?


texts: How do you stake / forge in nxt / ardor using a public node without having to login publicly?

texts:
I have a public nxt / ardor node, but how do I set it to stake / forge with my account? I'm planning to create a separate account and just lease my balance to it to forge.

What settings do I need set to make this work?


texts: possible to generate privatekey based on private key using bitcore.io?

texts:
Is is possible to generate the private key based on private key, means suppose if i am having one set as bellow :

privatekey : '02XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXacdefd'
publickey  : '032XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
Address    : 'MnasXXXXXXXXXXXXXXXXXXXXXXXXXXXX'

suppose we consider for example above is one wallet now i want to create sub wallet of it then is possible something

privatekey : '02XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXacdefe'
publickey  : '032XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
Address    : 'MnasXXXXXXXXXXXXXXXXXXXXXXXXXXXX'

just change last digit of private key like 'd' to 'e' and we consider that one is sub wallet.

Is it possible with bitcore library.? or it the correct way to do..?


texts: How can I transfer my BitCoins to my PayPal?

texts: How can I transfer my bitcoins to PayPal?


texts:
Let’s say I want to generate many private keys so I can generate one private key (and thus a public key) identical to the richest bitcoin address.

But I can’t do that because my computer power is not enough.

What about if I create many machines, like the mining machines, but instead of generating hashes, they would only generate private keys, Let’s call them “Keying machines”

So I have many of those Keying machines generating thousands of thousands of thousands of private keys per minute.

These machines will only stop if and only if they recreate the private key-public key of the richest bitcoin address : 385cR5DM96n1HvBDMzLHPYcw89fZAXULJP )

Is this idea actually possible?


texts: NXT single address per user vs bitcoin single address per transaction

texts: In bitcoin, the anonymity is ensured by creating a new address for each transaction and by associating this address with a wallet. As far as I understand, with NXT, you use your account (calculated by the system from your passphrase) for every transaction, so it is simple by browsing the blockchain to trace all exchanges behind an account and a person. Is there any plan to address that ?


texts: Will mining in the (far) future produce a payout?

texts:
According to this question, there will only be 21 million bitcoins at most. These coins are being produced logarithmically by mining, so the payout will decrease as time goes by.

When all 21 million bitcoins are in circulation, will there be any reason for mining? Is mining only useful for us "early adopters" or will it be a permanent part of Bitcoin?


texts: Integrating Bitcoin payment methods to a UK Opencart store?

texts:
I really want to integrate Bitcoin into my girlfriend's web store, but have found that they are either too expensive per transaction for international payments (bips.me - $7.50), have a huge minimum withdrawal threshold for international bank accounts (bitpay - $1,000) or simply don't work with international bank accounts at all (coinbase)

Is there any payment module I've overlooked that will work with Opencart, and will pay in £GBP to a UK bank account?

Thanks


texts: The result of bitcoin-cli getpeerinfo command

texts:
When I type bitcoin-cli getpeerinfo in shell, conspicuous property of the result are addr and addrlocal addrbind.

14.xx is my address and others are peer's address.
I know that Bitcoin client can do port forwarding using UPnP query to my router.
so, I checked my router whether the port number(48302, 44660) is opened or not but, no any port is currently open.
This is very strange point. my peers should cannot communicate with me without port forwarding since I'm using router.

Can you give information technically?

Sorry for my English


texts: Wallet Balance does not match Transaction Total

texts: Obviously, I am a newbie.....I have made several "buys" on Coinbase and the Wallet balance does not match the transaction totals - they are off a considerable percentage amount. Am I looking at it wrong or what?


texts:
SPV clients typically connect to full node peers and set filters on what information they download. How many SPV peers can a single full node support, typically?

Is it reasonable to expect millions of SPV node users connecting to ~6,000 full nodes?


texts:
I'd like to accept freelance work with bitcoin, probably a large enough amount to consult a lawyer.

What kinds of questions would you ask to make sure they're competent? How would you go about finding such an attorney?


texts:
Let's say a lightning node A wants to route a payment to a lightning node B, being A and B not directly connected.A looks for routes throughout the network, using the info about the total capacity of available channels and construct n possible routes to reach B.

Will A just try routes until eventually one of the n succeeds?

For what I've got by checking the BOLTS, the actual state of each sides of the channels is not announced (is it?), what means that even though a route could have enough capacity to route a payment, one of the channel could be unbalanced and the whole route may fail. Therefore, the potential failure rate when trying to route payments seems quite high.

Am I missing something?


texts: What parts of Bitcoin (litecoin etc) are Little Endian?

texts:
As mentioned on this Hardfork Wishlist, many developers want Bitcoin to be entirely Big Endian for consistency and performance reasons.

I'm looking for a concise list of all the areas that Bitcoin uses data in Little (or Big) Endian format so I can create an "endian coin" just for the purposes of testing capacity and performance.


texts: Does bitcoind not support txindex=1 option in regtest mode?

texts:
Is it possible to specify txindex=1 option in bitcoin.conf or elsewhere?
It doesn't seem to work. Whenever I run bitcoind -daemon, it stops.

If I remove txindex=1 from the conf file, it works.

I am using regtest mode.

Here is the conf file:

rpcuser=abc
rpcpassword=secret
regtest=1
rpcport=8332
txindex=1


texts: Initital block downloading does not start

texts:
I've installed bitcoind as said:

sudo apt-add-repository ppa:bitcoin/bitcoin
sudo apt-get update
sudo apt-get install bitcoin-qt

Then I started server, running bitcoind -daemon

But initial block download doesn start for some reason. When I call bitcoin-cli getblockchaininfo verificationprogress is always 0.0000000

On my local machine everything went well and seems that I have to fix network settings to be able to run bitcoin on remote server at collocation. But I have now Idea what to fix and where to look. I've searched google all the way up and down, I've tried setting proxy=127.0.0.1:9050 - no effect :(

Pls help - how do I make bitcoind to connect to peers?


texts: Bitcoin cash not syncing the current block

texts: I have installed BCH "Bitcoin Unlimited Cash Edition  bucash1.7.0.0". Problem is the current block is not synced in our wallet server, the server is stuck at block "635258". How to rectify this problem, please suggests me


texts: How is proper fee rate got on Bitcoin Cash

texts:
I'm developing wallet system trading BTC, BCH and so on.
In BTC, I'm using estimatesmartfee API to calculate by transaction size and relayfee to guarantee minimum fee and it works well.
In BCH, though most of logic is same as BTC except estimatesmartfee, estimatefee is used in BCH.
However, as increasing transaction size by input UTXOs, sendrawtransaction is often failed because of shortage of fee.

How should it implemented properly? What is it affected?
I guess some reasons,
If I need to use API to get proper fee rete from some sites, what is that site?


texts:
Hey guys I've been searching for quite some time... Is there any good, except mycelium, wallet which supports testnet Bitcoin Cash?

Thanks for answers in advance!
Cheers!


texts: Getting the wrong hashes for bitcoin core packages

texts:
I've been playing around learning more about Bitcoin and was following this tutorial from 21.co on digital signatures.

When I open the SHA256SUMS.asc file and try to verify the packages, I get different hashes than what's in the file.

curl -O https://bitcoin.org/bin/bitcoin-core-0.11.0.tar.gz

shasum -a 256 bitcoin-core-0.11.0.tar.gz

This gives the following output:

69b00985c84e6633cc2e518914436ce55666cc10d1edf15ee442758d9f8d5219  bitcoin-core-0.11.0.tar.gz

Which is very different from what is in the file:

c7a5e496d7c31bdc10d2c0c79dfcf9aca69f9520579917c7d3e95868b2127707  bitcoin-0.11.0-osx64.tar.gz

NOTE: I'm using a different command then what is mentioned in the tutorial for checking the hashes. shasum -a 256 instead of sha256sum.

Am I doing something wrong here?


texts: How can I request payment to a set of addresses?

texts:
I am building a payment processing service where a single payment may be split among multiple individuals. While it would be possible for me to write the service in such a manner that a customer pays to a single address, and then an secondary process creates the single-input-many-output transaction, it would be preferable if I could simply request that the transaction signed by the customer directly produce the desired outputs.

Is there any standard way to create such a payment request? Bitcoin URLs allow only a single address (and single amount) to be specified. Is there a way to create a partially complete transaction (specifying multiple outputs) in such a way that a customer's wallet software can correctly choose and fill in the appropriate UTXOs for inputs, and add an another output for the change?

Barring that, is there any precedent (and convenient method) for asking customers to provide UTXOs to use as inputs, and then generate the transaction for them to sign? I know that all this would be achievable if I were to provide custom wallet software, but that's certainly something I wish to avoid if possible.

EDIT:

I've found https://github.com/bitcoin/bips/blob/master/bip-0070.mediawiki, which seems to be close to what I want; how widely supported is this protocol?


texts:
I just reindexed a node that was already synced (in order to enable txindex); it took around 9 hours. It's on a pretty good system: 16G RAM, i7 with 4 physical cores. Storage is a weak point, with LUKS on software RAID0 on spinning disks. dbcache is at the default 100M, though I'm running 0.11 so I gather this ends up smaller than the previous default due to more accurate accounting. By extrapolation from testing a subset, a sequential read of the full ~38G of blk files should take ~4 minutes.

I understand reindex includes rebuilding the chainstate db, so I'm guessing that's the bottleneck. Questions: 1) reindex doesn't also re-validate blocks, does it? 2) Any experience with speeding this up -- perhaps putting chainstate on a tmpfs and copying to permanent storage once complete?

Followup: by increasing dbcache as suggested, and adding a recent custom checkpoint to the code, I got another reindex done in about 3 hours.


texts: What are the preferred UI images for Bitcoin Address & private key and multi-signature key?

texts:
How should I visually distinguish between the different types of keys available for the end user?

So far the common keys I've come across are

Private key (not to be shared)
Bitcoin address (to be shared, and may or may not have a backing private key)
Compressed public key
Casascius keys (where the private key is split in half totaling 3 keys)
Multi signatures


texts: Would this alternative to Proof of Work work?

texts: I'm fairly new to the subject, but I've read enough to figure out that Proof of Work has a problem concerning mining pools, and other alternatives don't seem to convince me either. I thought of my own, but since I'm new I wanted advice to see if it could be implemented/improved or if its just garbage. So instead of having everyone mine, I thought 3 random "validators" could be picked to do the hash-math. Only if all 3 get the same result, it is stored to a "temporary" blockchain. And only if say the next 3 blocks worked with that result, it will be placed in the actual Blockchain. If 1 of 3 gets a different hash, 3 other random people are selected to validate. I thought this could help with problems of the 51% and energy consumption. I guess I could call it Proof if Three. It was just a thought experiment. Any feedback is welcome.


texts: How do I call getblocktemplate from C#'s bitcoinlib?

texts:
How do I call getblocktemplate from the bitcoinlib package for C#?
This call does not work
ICoinService CoinService = new BitcoinService(useTestnet: true);
var blockTemplate = CoinService.GetBlockTemplate();


texts: How much on-chain activity is to and from exchanges?

texts: Are there any data services which provide metrics that show how much of the transactions on the Bitcoin blockchain are to and from exchanges?


texts: Bitcoin-QT: which external memory (connected via USB2.0 + TrueCrypt) would work?

texts:
Background
I have Bitcoin-QT 0.9.3 (zip version). bitcoin-qt.exe sits on the internal HDD of my laptop. All of the other stuff (blockchain, wallet,...) on a 128GB USB drive, fully encrypted with TrueCrypt (AES encryption), connected via USB2.0 port. I have bootstrap.dat (21GB copy of blockchain) on the USB drive, too.
Problem
everything is slow via USB2.0 flashdrive. Import of bootstrap.dat  file is barely making progress. It's been 7 days and I'm getting older. The progress bar shows it's 1/3 ready. No other application reads/writes to the USB drive.
Question
I'm considering swapping my flash drive for an external hard drive, but keeping TrueCrypt. Would this help, or would the fact that I have no USB3.0 ports be more important? I'm looking for satisfactory speed results that other people are getting by using bootstrap.dat. As slow as it's going, I'll import the blockchain slower than it's generated.
I would prefer your experience over suggestions like "try this..." becase I don't have free HDD space to "experiment", I just want to buy some HDD and hook it up to USB, but I'm worried that USB2.0 port itself is a bottleneck and I would just waste money. Thus I'm here for clues.
I'd prefer an HDD instead of an SSD, but I will hear out both options. I'm not interested in thin clients.
(basically I'm looking for cheapest external memory that would work, because flash drives don't work with Bitcoin-QT).


texts: Decreasing Energy Consumption of Bitcoin's PoW with paired mining rounds

texts:
I found the following whitepaper on an algorithm called "Green-PoW" by the authors and i'm quite sure this would be a perfacet solution and also would get acceptance by the miners and the community.
You can find the white paper here:
https://arxiv.org/pdf/2007.04086.pdf
Key point of the paper here as a quote:

"In order to reduce the energy consumption in PoW, Green-PoW considers
mining rounds in pairs and adjusts the election mechanism during the
first mining round in the pair, to allow the election of a small
subset of miners that will exclusively mine in the second round.
Assuming the total network hashing power is equally distributed among
miners, a significant energy saving up to 50% could thus be achieved"

What is your opinion on this approach, are there any problems with this?


texts: BTC-e doesn't appear to allow USA wires from banks, and it has other options like MoneyPolo or OKPAY, neither of which allow USA customers either.  I've seen bitcoin traders arbitrage trade using US Dollars with BTC-e and they are Americans, so I'm curious how Americans use BTC-e outside of transferring bitcoin from one site to BTC-e?


texts: I upgraded bitcoind to 0.8 from 0.7, may I delete the old blocks?

texts:
Upgrading to 0.8 from 0.7 I noticed the old blk*.dat files were untouched, while it was created a new directory called blocks/.

I guess I can delete the old blk*.dat files? Is there something else I'm supposed to delete?


texts: Smaller transactions are easier to validate; larger transactions take more work in Bitcoin

texts:
I am working on Bitcoin and trying to understand how transaction fee is calculated. Bitcoin support site states that the reason for selection of small and large transaction by miner:

  Again due to the fact that a block on the bitcoin blockchain can
  contain no more than 1 MB of information, transaction size is an
  important consideration for miners. Smaller transactions are easier to
  validate; larger transactions take more work, and take up more space
  in the block. For this reason, miners prefer to include smaller
  transactions. A larger transaction will require a larger fee to be
  included in the next block.

https://support.blockchain.com/hc/en-us/articles/360000939883-Explaining-bitcoin-transaction-fees

I have below questions on it:

Does the size difference matter only in case of validation or even while mining or PoW.
What is the mathematical reasoning for difference.


texts: How do Bitcoin mining pools send their miner's their share of the block reward

texts:
In most bitcoin mining pools, miners of a pool are sent their portion of a block reward that the pool collectively mines, every 30 minutes or 1 hour.

How exactly does a mining pool tell the Bitcoin network to send these coins to each of the miner's addresses?


texts: Is Kim Dotcom's "Megacard" a viable possibility for bitcoin?

texts:
A week ago Kim Dotcom posted that a Bitcoin Credit Card would be something that he would be keen to support. Apart from Bitcurex, which is a different system and slightly lacking in credability and trustworthiness, I'm interested in a card which works like a credit card but is intrinsically integrated with the BTC system.
Due to the nature of Bitcoin, would a credit card-esque form of payment actually be viable?
 If so, how?


texts:
I have installed full node on ubuntu server to make a bitcoin payment processor like Bitpay.

I have generated new address for each invoice with $bitcoin->getnewaddress();

As a result, it created new addresses with different private keys.

Each address has around $5 - $20 in it like 50 - 70 different addresses.

When I want to transfer all balance to another bitcoin wallet, I get error -> This transaction requires at least 0.03 Miner fee.

Which is not fair because I already have 0.05 BTC in this wallet, paying 0.03 fee is not logical. Sending $750 is requirind $400 fee.

Any ideas to reduce fee?


texts:
I am aware that Satoshi Nakamoto is the author of the paper that originated Bitcoin and the creator of the original bitcoin client. However, I often hear the term Satoshi as if it was a monetary unit.

What is a Satoshi?


texts: Is scaling Bitcoin heading it to a dead end?

texts:
The immutability of any given blockchain is reinforced by the total hashing power behind it. Proof of work (ergo a financial commitment) is a necessity to ensure the party verifying transactions is incentivized to do so honestly.

Currently (April 2018) mining profitability is relatively low and may soon become limited to those with really cheap electricity. This is before any scaling solutions have really come into full force with Bitcoin.

With the next block halving in 2020 (one of many more to come) and scaling solutions becoming mainstream will there still be enough incentive for miners to support the blockchain?


texts:
After withdrawing bitcoin from a site I use I sent it straight to another site with a generated address, on my site it said it was completed but was never received on the other site. The three addresses are

1BVLvno6UX8Rn3KtAQgJcpcZca58bcjVc6

8uskrzBQKwbhWHL7LYFMAD5yCNH6vTLnj

37eHZRcG9G3q3ZE7a3x5qYmWnhFeiThnKR


texts: How can i emulate two or more recipient address?

texts:
https://webbtc.com/scripts/multisig

Above site lists lots of multisig recipient addresses having
2 or more addresses like below bitcoin mainnet transaction.

  getrawtransaction fe709089a2a2142b82f9f57745452eff0f5feb9d6e02a6ad87b8faf4750c8a16 true

  {

  "txid": "fe709089a2a2142b82f9f57745452eff0f5feb9d6e02a6ad87b8faf4750c8a16",

  ...
    "vin": [
      {
        ...
      },
      {
        ...
      }
    ],

  "vout": [
      {

  "value": 0.00010000,
  "n": 0,
  "scriptPubKey": {
  ...
    "type": "multisig",
    "addresses": [
      "1FE1A8QAF1d9WyLR67h4bZD5Q8gMAHF8Aq",
      "17mKFkUqi8Q1zLqRjjQZgHWpE4yboBFjbM"
    ]
  }
},
{
  "value": 0.00000000,
  "n": 1,
...
}

  ],
    ...
  }

addmultisigaddress offers multisig address composed of below.

  bitcoin-cli addmultisigaddress 2 '["2Mv4H342fBrP6aJWnSem3bstNGqmrsfJkWH", "2NA6BSeYvtaY6iRhx9ZRQdPdsAzHE6E7Kcz", "2N9sxVZHzJGCZGXLhEZ2hNQUXgWLxgHfjFQ"]'

  {

  "address": "2Mt69kBHVgAeyDcPSYtcuhDmwZGVcfgDBs6",

  "redeemScript":
  "5221036e92f34d7cef7dd069d3cc41ac4f7aa5d08964a97fad73a9c736d0f62e086d662103a5cafce0576b6af5b963c8208ebbdf6474af31b9b5cbfce0791e3c6d4f6e8cd021029bd48294dede37c6689597ff8f33c3ad7b53eb604a1208da8dd39312825d32d653ae"

  "scriptPubKey": "a9140940d70f73f5d7c3291aa5627b2c20ae46fd732387"

  }

I created multisig address("2Mt69kBHVgAeyDcPSYtcuhDmwZGVcfgDBs6") above, and sent money to the address using createrawtransaction.

The expected result "vout.scriptPubKey.addresses" tag was

  "addresses":

    [
          "2Mv4H342fBrP6aJWnSem3bstNGqmrsfJkWH",
          "2NA6BSeYvtaY6iRhx9ZRQdPdsAzHE6E7Kcz",
         "2N9sxVZHzJGCZGXLhEZ2hNQUXgWLxgHfjFQ",
     ],

but the result was

  "addresses": [
        "2Mt69kBHVgAeyDcPSYtcuhDmwZGVcfgDBs6"
     ],


texts: I can't seem to find the bitcoind binaries for Mac--just the bitcoin-qt GUI application. Can someone give me a link, please?


texts: Is this man-in-the-middle double-spending attack against Bitcoin viable?

texts:
There is an almost trivial double-spending attack against Bitcoin if an attacker has a MITM (man-in-the-middle) attack against a victim: the attacker prevents all blocks from being seen, and replaces them with their own.  The argument against this I've read online is that "it will take an extremely long time for the attacker to generate their own blocks, so the victim will notice there's something wrong".

But what about the following attack?

Attacker "Mallory" has a MITM attack against victim "Alice".  Say it takes Mallory T minutes to generate a block, where T >> 10
When the N-th block is generated on the network, Mallory waits C*N minutes before forwarding it to Alice  (here C is a small arbitrary constant, and N=1 is the first block generated on the network after the MITM attack begins).  In other words, only a small amount of time is added to each block, but Alice's blockchain gets further and further behind the "real" blockchain as time goes on.
Let M=6*T/C.  After M blocks, Alice's blockchain will be C*M = 6*T minutes behind the real blockchain.  Mallory starts generating blocks against the real blockchain's head at this point.  She inserts a malicious fake transaction into the first block she finds, and fills the rest with transactions from the real blockchain.
By the time Alice catches up to that point of the blockchain, Mallory will have generated 6 blocks, enough to make Alice believe the malicious transaction has been confirmed.

In other words, Mallory builds up time for herself to generate some blocks by adding C extra minutes between each block.  Once she's accumulated enough time, she then "spends" it to generate some fake blocks.

Alice still sees a block ~every 10+C minutes, so as long as C is small she never notices anything is wrong.  She also sees her own transactions eventually going through, just with an extra delay of N*C minutes.

Does Bitcoin somehow protect against this?  Or is this a legitimate double-spending attack?


texts:
Hello I am using an old BitCoin client named MultiBit v.0.5.18. There is no option to change a fee. My transactions that I was send two days ago still in 'Unconfirmed status' and I guess here is a problem because I cannot move money from this wallet and may will never can do it.

The wallet set the default fee to 44.843 sat/B. It is lower for current time. I see the middle fee is 220 sat/b for now from https://bitcoinfees.21.co/.

How can I solve the problem? Is it possible to open wallet through another client? Electrum for example. Or I should wait when fees will go down (if not?).


texts: Step by Step instructions on installing Bitcoin Core 0.14 on Raspberry Pi Zero and 1/2/3?

texts: I couldn't find a concise tutorial on how to setup Bitcoin Core v0.14 on Raspberry Pi Zero or 1/2/3. Let's say I have a brand new raspberry pi without any image flashed. What are the step by step instructions to get this thing running as a Bitcoin Core node? Assume I only have a 4GB SD card as I noticed that the new .14 version of Core has the ability to prune the blockchain all the way down to 500mb.


texts:
I recently read an article on Bitcoin Media, that claimed:

  Jeff Garzik pointed out that Bitcoin-Qt no longer operates using the IRC bootstrap, and on inspection he’s right. This mainly applies to older versions of bitcoin.

Implying that the IRC channel is no longer used by Bitcoin-QT. Is this true, and if so, which version of the standard Bitcoin client was the first not to use the IRC channel?


texts:
This is not a duplicate of previous, similar questions I've read on StackExchange, since none of those questions, nor the answers, go into the difficulty theory, as espoused on the Bitcoin Wiki.

Basically, I'm trying to calculate the number of attempts a miner needs to find a hash less than the target difficulty, through using some of the technical docs' on the Bitcoin Wiki. Hence, my answer is based on examples on that Wiki, but some of the explanations there are somewhat ambiguous. For example, I'm uncertain if the writer means difficulty1Target (they use difficulty_1_target), or difficulty 1. Therefore, I would be grateful if someone much more knowledgeable than I could run through my reasoning and also check my answer at the end.

  The difficulty is calculated thus:

  difficulty = difficulty1Target / currentTarget

  Where target is a 256-bit (32-byte) number and difficulty1Target
  represents a hash where the leading 32 bits are zero and the rest are
  one. That is known as pool difficulty or pdiff. Floating point
  targets with limited precision allow clients to approximate
  difficulty. Such approximations are known as bdiff.

  Each block stores a packed representation of the hexadecimal target.
  Supposing a target of 0x1b0404cb, the hexadecimal target is:

  0x0404cb * 2^(8*(0x1b - 3)) = 0x00000000000404CB000000000000000000000000000000000000000000000000

  Where 0x0404cb is a signed value. The largest legal value for that
  field is 0x7fffff and the smallest value is 0x008000.

  The highest possible target, difficulty1Target, is defined as
  0x1d00ffff. That gives a hexadecimal difficulty target of:

  0x00ffff * 2^(8*(0x1d - 3)) = 0x00000000FFFF0000000000000000000000000000000000000000000000000000

  Pooled mining often uses non-truncated targets, giving a
  difficulty1Target of:

  0x00000000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF

  Hence, the bdiff difficulty at 0x1b0404cb is given by:

  0x00000000FFFF0000000000000000000000000000000000000000000000000000 / 0x00000000000404CB000000000000000000000000000000000000000000000000
  = 16307.420938523983

  And the pdiff difficulty is:

  0x00000000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF / 0x00000000000404CB000000000000000000000000000000000000000000000000
  = 16307.669773817162

  The following formula shifts the target difficulty so that it is
  offset against the difficulty1Target:

  0xffff * 2^208

  And to offset for difficulty D, we have:

  (0xffff * 2^208)/D

  Since a calculated hash to test against the target will be a random
  number between 0 and 2**256-1 (SHA-256 is a 256-bit value), for any
  given difficulty D, the algorithm for estimating the average number of
  calculations needed before finding a solution, is as follows:

  D * 2^256 / (0xffff * 2^208), or just D * 2^48 / 0xffff [@BitcoinWiki_Difficulty_2018].

  Hence, the estimated number of calculations needed to find a hash
  given the  bdiff difficulty at 0x1b0404cb is:

  16307.420938523983 * 2^48 / 0xffff = 7.0040908e+13

Many thanks!


texts: How do I send a transaction directly to a miner or pool for processing?

texts: I am interested in sending a transaction directly to a miner or a pool for processing.  I have general familiarity with Bitcoin-QT.  What additional knowledge and steps must I have in order to send a transaction directly to a pool?


texts: Since NXT aliases are like domain names. Do they expire? Currently alot of people are squatting aliases and was wondering how the NXT community plan on fighting that?


texts: Is there any way to generate bitcoin addresses  other than the Blockchain API? (given the fact that it is not public)


texts: Blockchain.info, does recovery phrase recover all wallets?

texts:
I need some help understanding blockchain.info.

1.

Under the Default wallet, I can generate multiple addresses and also see the Extended Public Key (xPub). If I go to the iancoleman BIP39 mnemonic converter, and input my backup phrase, it shows all the addressed I generated in the default wallet, and also shows my Extended Public Key (xPub).

But:

If I add a new wallet by clicking "Add", and create addresses under it, I do not see these addresses on the bip39 page:
https://i.imgur.com/0LZcxWq.png
This wallet also has a different xPub that is not on the bip39 page:
https://i.imgur.com/WDlXZHz.png

Can someone please explain this?

2.

The wallet recovery backup phrase, does it only backup the default wallet (and all addresses in it)? Or does it backup all wallets within blockchain.info ? (I am talking about wallets created using the "Add" button, NOT another account with a different email).

The reason I'm confused, as I stated above, if I input the recovery phrase in the BIP page, it only shows the xPub and addresses associated with the default wallet only.

If someone help please?

Thank you!


texts: why is the double spending problem is a problem in cryptocurrency?

texts: The bitcoin original has the "double spending problem." But in a transaction using standard currency (dollar), the double spending problem is not a problem. Why is this a problem in crypocurrency?


texts: is it possible to be able to buy cryptocurrencies other than bitcoin, litecoin and eth with USD

texts:
I've been looking online for quite sometime but it doesn't seem like I can find this exact answer. I've been looking to buy some cryptocurrencies but I'm hoping to be able to buy them with USD.

I know that I can go to coinbase, open an account, buy bitcoin, or ether and then transfer it to an exchange such as bittrex or bitstamp and get coins using those two main cryptocurrencies.

What if I want Ripple or DASH and want to buy it directly at the price that it's at, and i do not want to buy Bitcoin or Ether to get it (since the prices are so high).

Basically I'm not interested in buying Ether or Bitcoin, i'm looking to buy some other cryptocurrencies that are very low in price.

Am I able to do that - or do I HAVE to use Bitcoin or Ether to buy the desired ctyptocurrencies.


texts: How can i get the public key of my segwit address with my extended public key. when i import the xpub into electrum it automatically creates a legacy wallet for me. i'm not with my nano and won't be with it for a while, please how do i go about it, thanks.


texts: Sendfrom en senttoaddress both have [comment] and [comment-to] as arguments. Comment uses the script to put in a message, thus in a semi-standardized manner. Does comment-to encrypt the message with that public key? I'm kind of guessing in the dark without any explanation. (I'd suggest the tags API, RPC or JSON-RPC but I've no reputation)


texts: Always the same deposit address for a user?

texts:
I'm wondering if it is possible to at creation of a user account also save a deposit address(blockchain.info receive payments API) which the user will always use when he/she wants to deposit coins.

Ofcourse I know it's possible to save the deposit address with the user but will it work to always have the users always deposit to a specific address?

will it cause any problems like take the total received balance of the address all the time when the user deposits? eg: balance = balance + (total received coins + just deposited coins)

Tried to explain my concerns and questions to the best of my ability hopefully I can get some answers because google doesn't have any in this case.


texts: Bitcoin is attacked by China miners by screwing with the network, what will Bitcoin do?

texts:
There was a report recently (https://arxiv.org/pdf/1810.02466.pdf) that stated that China controls 74% of the hashing power. They can choose to collude and attack the network by either doing a 51% attack or stall the network by not including any transactions.

If China did attack the Bitcoin network. Are there any contingency plans in place to recover the network with a fork of some sort? What would happen?


texts: What other wallet service has integrated a message attach feature like public notes used in blockchain.info wallets?

texts: What other block explorers or wallets that has integrated a public note feature like blockchain.info? I'm looking to attach messages to transactions.


texts: Bitcoin mining - is it a race and how to not waste resources?

texts:
My question term race is not about race attack term.

I've read https://en.wikipedia.org/wiki/Bitcoin and want to get practice using Bitcoin, no need to recover electricity bills and get profit now.

One of things not clear to me - is creating new block a race? That is, whichever mining pool first solves puzzle will get the reward, others just wasted processing efforts for that block? If yes, how do small pools compete with the largest one?

If I install say p2p mining software on ordinary PC, can I expect to gain some micro-microbitcoins in several hours (as block is added each 10 minites)? If I join largest pool?

Does mining always means gaining both new bitcoins issued and transaction fees?


texts: Is verification of a blockchain computationally cheaper than recreating it?

texts:
One of the advantages of cryptocurrencies like Bitcoin that is often repeated is how hard it should be to manipulate past transactions. The reason that is often stated is that you would have to re-calculate all the headers with all the hash values of the whole chain which is practically un-doable.

My question is: How do you verify the blockchain integrity? Don't you also have to recalculate all the values to see whether they are valid? Or is the complexity class of verification different from creating a new chain? In other words is there some asymmetry at work here and if yes how does it work?


texts: How to put QR Code whenever I generate a unique address? block.io API

texts:
Hi guys as the title says. how can I generate a QR code whenever the block_io.php generates a unique address? I seem to have a problem when calling $newAddressInfo or $newAddressInfo->data->address whenever I'm echo-ing it. Please disregard the missing characters as per it's perfectly working.
so this is the whole script.

Bitcoin Address validator from Kyle : HIS YOUTUBE CHANNEL
QR GENERATOR FROM : TERRAGON

I just tweaked kyle's script.

SCRIPT :

require_once ("block_io.php");

$apiKey = "myAPIkey";

$version = 2; // API version

$pin = "myPin";

$block_io = new BlockIo($apiKey, $pin, $version);

if(isset($_POST['submit'])){
    $newAddressInfo = $block_io->get_new_address();
    $address = $_POST['addr'];
    $decoded = decodeBase58($address);

    $d1 = hash("sha256", substr($decoded,0,21), true);
    $d2 = hash("sha256", $d1, true);

    if(substr_compare($decoded, $d2, 21, 4)){
        $message = "Invalid Bitcoin Address";
    } else {
        $message1 = "Valid Address";
        $message2 = "Your Receiving Address : ";
    }
}

function decodeBase58($input) {
    $alphabet = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";

    $out = array_fill(0, 25, 0);
    for($i=0;$i<strlen($input);$i++){
        if(($p=strpos($alphabet, $input[$i]))===false){
                throw new \Exception("invalid character found");
        }
        $c = $p;
        for ($j = 25; $j--; ) {
                $c += (int)(58 * $out[$j]);
                $out[$j] = (int)($c % 256);
                $c /= 256;
                $c = (int)$c;
        }
        if($c != 0){
            throw new \Exception("address too long");
        }
    }

    $result = "";
    foreach($out as $val){
            $result .= chr($val);
    }

    return $result;
}

</form method="post">
    <input style="width: 100%;" name="addr" type="text">
<input name="submit" type="submit">

if (isset($message)){ echo $message; }

 if (isset($message2)){ echo " Your Unique Deposit Address: " .$newAddressInfo->data->address."
"; }

 if (isset($message2)) $str = "Your Receiving Address : ";
 $str ; echo $address = $_POST['addr'];

 if (isset($message2)){ echo img src='qr/qr_img.php?d=$newAddressInfo->data->address'> ; }

</form>


texts: How To get Address Public Key from Account XPUB?

texts:
I am little bit confused or not able to get the right Address Node Public key from Account XPUB.
What I have done :

Get the Account XPUB [78Bytes]

SHA-256

SHA-256 Again

Created Extended XPUB (XPUB + 4 Start Byte of Step 3)

Base 58 ENC

hdnode_deserialize()

Account Node  Change Node

Change Node  Address Node.

But am not able to get the right Public Address.
Please let me know if I have done something wrong.


texts: BTC Transfer from One Exchange Vendor to Other Exchange Vendor

texts:
It's my first time doing transfer with BTC. I have read from some articles that if you send BTC with low transfer fee it will be stuck in the network and the status is 'unconfirmed'.

I was sending ~0.049 BTC from one merchant to another merchant (BTCMarkets to Binance). I'm not sure how it performs but somehow my transfer was joined with someone else transfer. The other transfer was confirmed but my transfer is still unconfirmed. I also have no idea how to 'control' the transfer fee since I only paid the withdrawal fee from BTCMarkets. Below is the tx for the transfer. The ~0.0049 BTC was my transfer which is still unconfirmed.

https://blockchain.info/tx/e75f48c3fa06de6198fc0fbac0f2a2eadcdd6608ca572757015d45cdba6c1f1a

Can anyone help how to un-stuck or reverse or change the status to 'confirm' for my transfer? Thanks all.


texts: How to get the Public Keys of a bitcoin User

texts:
Is there some way in which I could get the public key of a Bitcoin user ?

Lets say I have transaction with another Bitcoin user. Is there some means by which I can retrieve the public key of the Bitcoin address they used in our transaction?

How does https://slock.it/ guys does it ? From where do they get the public key from ?

https://www.youtube.com/watch?v=-Ht23KXic1k


texts: Does miner with CPFP look through all the possible combinations of descendants to find the one with the highest fee?

texts:
When there is a transaction with more descendants, does CPFP policy look through all possible combination of descendants to consider "together", to find which one has the best fee?

For example, when there is a dependency graph, looking like this

there are 6 possibilities to consider for A - {A}, {A, B}, {A, B, C}, {A,C}, {A,C,D}, {A,B,C,D}. Does CPFP miner look through all of them?

In this graph, there will be 25 such combinations, if I count correctly. Would bitcoin core look through all of them?


texts: Is there any way the Bitcoin network could resist a viral tainted-coin tagging system implemented by regulators?

texts:
Already it's possible for MtGox etc. to detect spends of coins that have certain well-known thefts in their history. If regulators forced audits on exchanges and key popular merchants, as well as keeping track of coins they deemed to have been involved in illegal activities, they could make these exchanges and merchants pay a small tax on these 'tainted' transactions and pass this cost on to the consumer.  As the regulators 'tainted' coin list would be public, it would become in more and more peoples interest to use wallet software which subscribes to the 'taint' list in order to reject coins they know will incur a penalty upon spending. The more the regulator raises the tax at the exchanges and audited merchants, the more people must join.

Audited exchanges and merchants would have to submit batches of all bitcoin addresses involved in their transactions to the regulator. Agents could perform random transactions with exchanges and merchants to make sure 100% of transaction IDs are reported.

Is this scenario realistic, and wouldn't this make Bitcoin ultimately a very controlled environment indeed?

('tainted' coins would still have value on black markets, creating a split system where bitcoins are no longer completely fungible)


texts: What is the difference between wallet balance, local balance and remote balance in the Lighting Network?

texts:
I am having a hard time understanding the difference between the different "balances" in the Lighting Network. For example, I am running an LND node and I have the following balances:
$ lncli walletbalance
{
    "total_balance": "13841305",
    "confirmed_balance": "13841305",
    "unconfirmed_balance": "0"
}

$ lncli listchannels | jq -r '.channels[].local_balance' | awk '{sum+=$1} END {print sum}'
4201392

$ lncli listchannels | jq -r '.channels[].remote_balance' | awk '{sum+=$1} END {print sum}'
23804004

What is the difference between the local balance and the wallet balance?
If my node forwards a transaction, where do the fees go, in the wallet, or in local?


texts:
Am testing LN with lnd 0.7 and autopilot on my testnet node
I can pay successfully invoices created by htlc.me
But when trying to receive payments, example :

lntb843700n1pwjyglqpp5laas3dxqgc5wx3dpl279spzlk9j96pmzp6fyyfkj9v0ju5l72jksdq0dp6xccewd4jjqvccqzpgxh7l8afrmnmuy9mz95mf6mr9mctedw4wxq3sy5gscvyuh55qp5zjnen78hehanr89qa20ptwfmdgk7rpgrt29y34affnwxv5eutgddgq8jh57x

Am getting :

Send Payment Failed
Payment failed to send. This can happen due to temporary network connectivity issues or an unexpected server error.

Also tried adding my node via "Request Peer Addition"

030bc9de6e201d2428eb80890d023d48ef752533453ec74b993b1fede28c178435@91.121.210.16:9736

And got :

Peer Connection Issue
Could not connect to peer :( Check that the address is correct?

I tried multiple times but still having the same issues
Port 9736 is open


texts: Hypothetical Scenario - How long does a network correction take?

texts:
Hypothetical scenario:

If China decided to stop bitcoin and forced all electrical companies to stop generating electricity (unlikely I know, but work with me for a minute), that I assume would force miners to switch to solar power, meaning there will be a huge drop in mining power, meaning, transactions would take longer etc, until the network corrects itself.

If mining power instantly dropped by 90% tomorrow, how long would this correction take? and how long would transactions take in such a scenario, until the network corrects itself?


texts: Is it possible to manually create a seed from the BIP 39 English word list, and enter them in the Trezor Model T recovery to create a wallet from those words. I know that choosing the 12 words doesn't work, because the last word is a checksum of the previous 11. Is there a way to determine the 12th word from the first 11?


texts: How to install Electrum wallet in an offline Linux computer?

texts:
So I want to play with the Electrum wallet, but as Cold Storage.

Then what I plan to do is to install a raw Ubuntu 16.04 LTS into a computer "A" which I will never plug to the internet.

So, with computer "B" that has internet connection, I first download all dependencies of electrum from apt guided by this related answer:

sudo apt-get --print-uris --yes -d --reinstall install python-qt4 python-pip $(sudo apt-cache depends yourpackage | grep "  Depends:" |  sed 's/  Depends://' | sed ':a;N;$!ba;s/\n//g') | grep ^\' | cut -d\' -f2 >downloads.list
wget --input-file downloads.list

Now I download Electrum's tar.gz file. The last version when writing this is:

wget https://download.electrum.org/2.7.12/Electrum-2.7.12.tar.gz

Then I download its pip dependencies:

pip download Electrum-2.7.12.tar.gz

Now I copy all the files to a USB disk and then from this disk, to computer A.

And I run:

sudo dpkg --install *.deb
sudo pip install Electrum-2.7.12.tar.gz

However, the second command fails. It seems that even if I downloaded its pip dependencies, it doesn't pick them up and still tries to connect to the internet.

How to go on here then?


texts: I just want to confirm if my logic is correct. If I send Bitcoin to my Trezor address while the Trezor is unplugged does the web wallet then receive the private keys from the transaction and only once the Trezor is plugged in again are the keys taken offline? Also access to the web wallet is impossible without the Trezor I assume (ignoring recovery seed). Technical answers are welcomed!


texts: Can ASIC miners easily be used to guess brainwallet passphrases?

texts:
After reading the Bitcoin wiki page for brainwallets it seems to me that mining equipment can be used to brute force brainwallet passphrases. Is this correct?

  "...so hackers can collectively try multiple trillions of passwords every second in the privacy of their own homes with the very same equipment they use for mining bitcoins (in the usual sense)."

How would one use an ASIC miner to brute force the blockchain with a dictionary attack?
What would the application logic look like?
Can a standalone(The Antminer S1 for instance) miner be "tricked" into believing it is doing normal work for a pool when actually just hashing random strings or would it need custom drivers?


texts: I read that Bitcoin addresses are single-use tokens. Is it my responsibility to generate new ones in Electrum?

texts: I am quite new to this, and started using Electrum today. I read on the Bitcoin Wiki that "unlike e-mail addresses, people have many different Bitcoin addresses and a unique address should be used for each transaction". Under the "Receive" tab in Electrum, I found a long address. Is that "Receiving address" the one that should be unique for each transaction? If that's the case, does Electrum generate a new one for me after receiving or do I have to do something myself?


texts: Pros / Cons of using the new bc1xxx segwit address vs the 3xxx segwit address?

texts: What are the pros/cons of using the new bc1xxx segwit address vs the 3xxx segwit address?


texts: Bitcoin-QT issues with non standard filesystem

texts:
I'm having issues with blockchain catchup that I believe to be related to the underlying file system.

Symptoms: Significantly behind the network, start client and begin catchup. Catchup proceeds for 1-2GB then halts. CPU usage is 0 for the process, but it holds 500MB-1GB RAM allocated. 0 connections. Console commands receive no response, so crashed process? If I restart the client it will proceed again for a similar length of time, then repeat the behaviour.

Last run:

BOOT AT: ~353355
STUCK AT: 359430

Logs show many of these errors:

2015-11-21 03:39:26 ERROR: AcceptToMemoryPool : nonstandard transaction: non-final

End of log:

2015-11-21 04:03:10 UpdateTip: new best=0000000000000000041ca40bdec7946dc4105fea0cefb26ea7fb8914880fe089  height=359623  log2_work=82.893042  tx=71115044  date=2015-06-06 04:15:15 progress=0.806010
2015-11-21 04:03:14 UpdateTip: new best=0000000000000000028104e61aabd1b31bd0a136c33daecdd92165126aeb7ce1  height=359624  log2_work=82.893074  tx=71115578  date=2015-06-06 04:29:37 progress=0.806021
2015-11-21 04:03:15 UpdateTip: new best=00000000000000000b0c4437cd594ae56bb6dc532c497af9b595b653311345f5  height=359625  log2_work=82.893107  tx=71115639  date=2015-06-06 04:26:21 progress=0.806019
2015-11-21 04:03:26 Pre-allocating up to position 0xd00000 in rev00278.dat
2015-11-21 04:11:27 UPnP Port Mapping successful.
2015-11-21 04:31:27 UPnP Port Mapping successful.
2015-11-21 04:51:27 UPnP Port Mapping successful.
2015-11-21 05:07:26 socket inactivity timeout
2015-11-21 05:09:30 socket inactivity timeout
2015-11-21 05:11:27 UPnP Port Mapping successful.
2015-11-21 05:31:27 UPnP Port Mapping successful.
2015-11-21 05:51:27 UPnP Port Mapping successful.
2015-11-21 06:11:27 UPnP Port Mapping successful.
2015-11-21 06:31:27 UPnP Port Mapping successful.
2015-11-21 06:51:27 UPnP Port Mapping successful.
2015-11-21 07:11:27 UPnP Port Mapping successful.
2015-11-21 07:31:27 UPnP Port Mapping successful.
2015-11-21 07:51:27 UPnP Port Mapping successful.
2015-11-21 08:11:27 UPnP Port Mapping successful.
2015-11-21 08:31:27 UPnP Port Mapping successful.
2015-11-21 08:51:28 UPnP Port Mapping successful.
2015-11-21 09:11:28 UPnP Port Mapping successful.
2015-11-21 09:31:28 UPnP Port Mapping successful.

This seems to happen on my Flexraid disk array(Snapshot RAID) that appears to the OS (2008R2) as a regular NTFS 8TB volume but not on a regular 160GB backup drive. I've seen issues once before when an application attempted to create many files at once, this was resolve by tweaking that applications write caching.

Any suggestions for tweaks to allow stable disk IO?

EDIT: Forgot client info

"version" : 90300, v0.9.3.0-g40d2041-beta
"protocolversion" : 70002,
"walletversion" : 60000,
"balance" : 2.27391276,
"blocks" : 353567,
"timeoffset" : 9,
"connections" : 8,

NB: Client is out of date BUT I've tested with the latest LTC-QT and have the same RAID no single yes behaviour so its unlikely the cause.


texts: Does the electrum client decide the best chain on the basis of how much work was done, or how long the chain is?

texts:
Bitcoin Core compares blockchains based on how much work they contain, and not necessarily which one is longest. This is useful for preventing time warp attacks.

This comment on HN says that the electrum client doesn't implement this, and just naively compares chain length:

  Yes. It's possible to create a long chain at low difficulty and the original bitcoin client protects against that by computing the total "work" that has gone in a chain. However, Electrum just assumes that the longest chain will be the one which has most "work" in it which is wrong.

It seems surprising that electrum would change a major consensus rule; I can't see any rationale for it.

Does the electrum client decide the best chain on the basis of how much work was done, (like Bitcoin Core) or how long the chain is?


texts: Create Sign and send bitcoin transaction using HD wallet

texts: I am new in bitcoin. I want to implement a bitcoin payment system. I am using blockcypher's API. Suppose we have an hd wallet "myhdwallet" and we have driven 2 addresses using xpub for my hd wallet. (address A=> m/0/1 ,address B=>m/0/2,...). I want to create a transaction and send some bitcoins from my wallet's addresses to destination address C. How can I do that? I was successful in sending bitcoin using private keys. But here I do not have any private key for addresses. I just have wallet name and xpub. How can I do that using blockcypher's API?


texts: Why do so many Bitcoin wallets and accounts exist?

texts:
Why so many bitcoin wallets do exist? Why it is not just single like other conventional currency? Multiple wallets means I have to have multipe accounts; is it possible to transact among multipe wallets bitcoins and if yes is it without fee?
For bitcoin account, public key is actually address which will be used in bitcoin transaction (sending bitcoins to me). And private key is used to decrypt the transaction. I also got to know that the key can also be changed. If my understanding is correct, what is the actual key for the bitcoin account?


texts: Where does the money i am receiving come from?

texts: Say i was to have 100,000 dollars worth of bitcoin in my wallet and i want to cash out, where does the money i am receiving come from? Is it taken out of the volume amount of dollars currently in circulation or can you only get paid out if someone is willing to buy it?


texts: Is there something about Bitcoin that prevents us from implementing the same privacy protocols of Monero and Zcash?

texts:
Certain coins like Monero and Zcash implement privacy protocols that make it nearly impossible to trace origin and destination of transactions - making them completely anonymous.
I'm curious as to why Bitcoin does not peruse a similar path to privacy.
Is there something about the Bitcoin Core code or the way Bitcoin functions at present that prevents it from pursuing this path in the future? Or is it related to extrinsic concerns that governments around the world might forcibly shut down the network if extreme privacy measures are employed?
Thanks


texts: Transferring bitcoins from my blockchain addresses to an exchange?

texts: What are the specific steps, in order, required to transfer my bitcoins from their blockchain wallets to a bitcoin exchange?  Please be specific.  Thanks


texts:
I am currently doing a project that requires blockchain to be applied to other systems. I was wondering where I can easily download the blockchain database and which is the best way of understanding blockchain.

Thank you


texts: Is there any advantage to owning physical bitcoins?

texts: The title pretty much says it all? Is there a security advantage to owning physical bitcoins such as those offered by Casascius? If so is it significant enough to justify the price difference between electronic and physical bitcoins?


texts: i don't know if there is an error in the scriptsig generation method of input in p2psh

texts:
I don't know if there is an error in the scriptsig generation method of input in P2PSH.

My address is a single signing address with one Private key，
I created a transaction that will generate hex string via Bitcoinj.

script = ScriptBuilder.createOutputScript(key.getAddress(params));
Sha256Hash hashForSign = transaction.hashForSignature(i, script, SigHash.ALL, false);
ECDSASignature signature = eckey.sign(hashForSign);
TransactionSignature tranSign = new TransactionSignature(signature, SigHash.ALL, false);
scriptSig = ScriptBuilder.createInputScript(tranSign, eckey);

But it is not the same as the hex string generated by the client RPC, but I don't know where it is wrong.

I will be very grateful if you can help me.


texts: How To Transfer Coins From Bitcoin Core to Electrum to avoid Sync Process?

texts:
I am super new to bitcoin and to be honest am not sure what I'm doing. I needed to buy something via bitcoin, and its recommendation was to download Bitcoin Core Wallet, so I did that and bought bitcoin to the receiving address on there, however I didn't know how much space was needed. So now I have sent the money to my Bitcoin Core address, but the wallet is trying to sync (and its taking forever which apparently is normal) and I'm not even sure my computer has enough space for it all. I read that I should try to transfer it over to Electrum, so I have that downloaded. I tried doing the Sweep Keys thing, but every time I try it, it says "no inputs found (note that input needs to be confirmed)"

Can anybody give me a hand here? I unfortunately will need pretty specific instructions..
Thanks :)


texts: Can we trust Aionnext exchange platform?

texts: I have a general question, if there is a list of regulatory approved exchange for cryptocurrency brokers?


texts: I understand how to send BTC to cold storage or offline wallets, but I can't seem to find information on how to send BTC from cold storage to, let's say, a wallet on my computer, or a website, or a friend's online or offline wallet.


texts: What will happen when all 21M bitcoins are mined?

texts: What will happen when all 21M BTC are mined ? How will miner get new coin as reward? In absence of it, the only option available will be to increase transaction fees? If I have to pay anyway fee, I can pay that to centralized entity now also. Help me understand.


texts: How to redeem a private key in case it is compromised

texts:
I know MtGox allows me to redeem a private key, but that doesn't necessarily ensure that all the value is extracted from that address in a timely manner. Is there no simple way to send the entire value of a private key to another address in case you believe the private key has been compromised? My real use for this is in having offline/paper wallets. I would like to transfer my bitcoins to an offline "savings" address, then when I want to make a withdrawal, be able to transfer the entire value of that private key to a new address because, having entered the private key somewhere to redeem its value, its privacy could have been compromised.

This seems like a very common use case for paper wallets. Am I missing something? It should be easier to spend the value from a particular address. Why can't I use my bitcoin client to spend a specific address? I can import private keys into bitcoin v0.7.1-beta (although even that is an obscure debug window) function, but it looks like sending from a specific address is also an obscure debug function (sendfrom). Why is this so obscure when it seems like such a common case? What is one to do if they suspect a particular address' private key of being compromised?

Also, how can I tell how much value is available on my various addresses to make sure I extract the full value? Blockchain.info seems to do a good job, but it's Dutch -- isn't there an English site or bitcoin client function to determine an address' value. That too seems really basic. I have tried blockexplorer.com, but that site rarely seems to work.

I feel like I'm trying to accomplish the most basic of tasks, and the tools just aren't there, so I must be missing something.

P.S. I am using also Android devices with BitcoinSpinner. I would be interested to know if some more sophisticated clients allow this more easily -- scanning both a private key as a source and a public key as a destination -- to create a transaction.

P.P.S I'm also not clear on how to use the backup provided by BitcoinSpinner. I tried to import it as a private key into bitcoin v0.7.1-beta on my desktop, but it didn't work. The only way I could figure out how to essentially get a backup of BitcounSpinner into my desktop's client was to import the private key, which I know is wrong. There must be some way that backups are supposed to work.


texts: When i open Multibit it tries to sync then says error, unable to load block chain. I can't figure it out. Don't know what to do about it.


texts: Get transaction details using bitcoinj library

texts:
I am trying to develop an application using bitcoinj library. I want to get the bitcoin transaction details.

The details, that I want to extract from a transaction includes the following.

1) Who send me the transaction (Address and Public Key of the sender).

2) The amount that I received.

3) When was the transaction issued.

4) Get the data stored in the transaction in OP_RETURN.


texts: How can I mine ALT SHA-256 coins using a Bitmain S4?

texts:
The bitmain S4 does 2TH/s out of the box with no overclocking.  For many alt SHA-256 coins, this can be 10% - 50% of the entire network hashing power, which would allow us to gain alt coins quickly, especially when the difficulty is low.  However, the S4 does not work with most mining pools except for BtcGuild and Slush's pool.  In fact, I have yet to find any Alt sha-256 pools that it works with consistently.

The problem seems to be in the fact that the version of cgminer the S4 uses does not support vardiff and can only mine at a diff setting of 2048.

Does anyone know of working alt sha-256 pools which have fixed diff ports at 2048?
I'm especially interested in switching pools which can mine several alt coins at max hash rate for the S4 specifically.

Please make sure the pool is working stably with an S4 before posting.


texts: I want to change 0.25 dollar cents in bitcoin for my digital content, is it too little?

texts:
I am a developer and very new in bitcoin world. I have plans of having website where I sell digital content for 0.25(or less) cents of dollars in bitcoin form.

What I understand is I have to pay for transaction fee for each purchase, I confess I don't know much about it.

If I want no fee can I develop my own "bitcoin transaction mechanism"?

Please, I need help thanks


texts: Key derivation in HD wallets using the extended private key vs hardened derivation

texts:
I am reading the book Mastering Bitcoin and confused about wallet key derivations in Chapter 4. Keys, Addresses, Wallets.

The book first mentions a private child key derivation where the child private key is derived from three inputs: (parent public key previously derived from parent private key, parent chain code, index).

Next, the book discusses extended keys and mentions two types: extended private keys and extended public keys.

The extended public keys are used to derive children public keys from parents public keys to avoid exposing the private keys, hence more secure. This is the block diagram for the extended public key.

On the other hand, the book mentions that the extended private key is used to derive a child's private key using the parent's private key and chain code.

However, although the extended public key does not expose the private key, it is still risky to use since it exposes the chain codes. If a private key is leaked, they can be used together to derive other children key.

Finally, the book suggest to use the hardened key, which to me is exactly the same description as the extended private key.

My question first question is, is the extended private key the same thing as the hardened key derivation?

My second question is, which technique is actually used when deriving the private key for children, the first one I mention in my question or the second one using the extended private key which to me is the same exact thing as the hardened key derivation.


texts: Extracting Bitcoin historical ticker data by setting up Bitcoin Node?

texts:
How do I extract the ticker data (historical values such as day price, day open, day close etc) by setting up a Bitcoin Node?
Bitcoin Node is setup using Bitcore.io

All blocks are syncing right now, but I don't really know how to get data?

Stack I use is Node.js with MongoDB

Thanks in advance!


texts: Is a peer connection maintained for the life of the node, or is it recreated on every request?

texts:
Lets assume we have 2 bitcoin nodes, A and B. A is already up, and B is now coming up. B lists A as a peer node and attempts to establish a connection. A accepts, a handshake is completed and they confirm they are in sync. Is the connection then terminated until there is a need to communicate with each-other again (ie a new transaction is broadcast)? Or is the connection persisted for the life time of the application?

If it is persisted, what prevents a well known public node from being swarmed with peer requests?


texts:
I am a political science graduate student looking to do research on bitcoin and cryptocurrency. To do so, however, I need data. While many datasets provide wonderful histories of bitcoin price and trade across time, I need data across space too for the type of research I am looking to do. I have found a large cache of data by countries' fiat currency used in transactions in the localbitcoins exchange here that does what I'm looking for, as an example: https://coin.dance/volume/localbitcoins/. I have also found graphs tracking traffic for major exchanges from Statista, but I haven't had any success finding or accessing the raw data. See here: https://www-statista-com.libdata.lib.ua.edu/statistics/944261/share-of-bittrex-visitors-by-country/ (same thing goes for the data for the data for Bithumb, Huobi, and Upbit on this site).
It doesn't matter to me so much what data exists (purchases, traffic, anything--I'm new to this stuff!) so long as there is some data out there on bitcoin by country. I also understand that this is a high ask considering the anonymity and decentralization of the blockchain, which are what attracted me to the topic in the first place. tl; dr where can I find bitcoin raw data by country?


texts: How to code the Simplest BitCoin CPU Miner?

texts: How would I go about making the simplest form of a CPU bitcoin miner? I have not been able to find documentation on the whole process...


texts: Does bitcoin have the potential to be subject to a hard fork where miners are forced to choose which fork they will accept, like Etherum?

texts:
Some background (Taken from Quartz):

  Ethereum is similar to bitcoin, but it also supports smart contracts,
  agreements written in computer code that execute automatically when
  conditions are met.

  Distributed Autonomous Organization (DAO) sought to build a humanless
  venture capital firm that would allow the investors to make all the
  decisions through smart contracts. It was one of the biggest
  crowdfunding effort in history. For Ethereum, the backbone of the
  project, it was a major vote of confidence in its nascent technology.

  Then it got hacked, when someone started siphoning money out of the
  DAO. By the end, the hacker, who has said that he was simply taking
  advantage of a technical loophole in the DAO, had amassed $50 million
  in ether, based on current exchange rates at the time. While the core
  developers who designed and run Ethereum didn’t really have anything
  to do with the DAO, they were left to deal with the mess, so they
  decided to hack the hacker.

  They managed to stop the theft and move the funds into another smart
  contract where they currently sit: a temporary fix. The way the code
  of DAO was written, there is a question of whether the original hacker
  can still lay claim to the funds. Fixing this would require more
  intervention from the core developers.

  Whether to do so has created an existential question for Ethereum. One
  of its underlying tenets is that it’s a decentralized platform,
  meaning the power lies almost exclusively with all of its users. By
  stepping in to fix this problem, it would completely undermine that
  objective. This has led to a heated debate between those who want to
  return the funds and others who say that the the power of smart
  contracts lies in their immutability.

  Doing so would basically eliminate the DAO, and move all the money
  into a smart contract that can only reimburse investors. The initial
  proposal was a soft fork where a majority of the Ethereum miners could
  voting on the roll back. Unfortunately, a security flaw was found in
  the voting process, which eliminated this option.

  That leaves a hard fork, where the core developers of Ethereum
  unilaterally make the decision to essentially create a new version of
  the network with different rules than the original. Then, miners,
  exchanges, and other major apps that are built on it need to decide if
  they want to a part of the new version of Ethereum or the original.


texts: Stock to Flow Calculation in JS - what am I missing?

texts:
I'm trying to calculate the S2F range price in Typescript but I'm not getting the same results as the https://digitalik.net/btc/ page for the same calculation, and I'm curious where mine falls down. What am I missing? It will be off, but not by this much.
tldr repl.it - https://replit.com/@notbrain/SupJo#index.js
My stock/flow numbers are way different, is coinmetrics blocks per day data accurate?

published 60 / 43
calculated: 64 / 35

Larger mini-app using coinmetrics.io api:

stock2Flow() function calls getBitcoinProduction()
getBitcoinProduction() uses coinmetrics api BlkCnt metric and sums block production * issuance based on last halving (the day's total blocks multiplied by either 12.5 or 6.25 depending on which side of 5/11/20 we're on)

production for 10 days is extrpolated out to 365 days for flow
production for 463 days is just used as is for flow

stock2flow() price calculation is Math.exp(-1.84) * Math.pow(SF, 3.36), where SF is the stock to flow ratio

import { DateTime } from 'luxon'
import axios from 'axios'

async function getBitcoinProduction(daysInArrears: number = 10): Promise<number> {
  const startDate = DateTime.local().minus({ days: daysInArrears }).toISODate()
  const urlBase = 'community-api.coinmetrics.io/v4'
  const urlMetric = 'timeseries/asset-metrics'
  let coinMetricsBlocksPerDayResponse
  try {
    coinMetricsBlocksPerDayResponse = await axios.get(`https://${urlBase}/${urlMetric}`, {
    params: {
      assets: 'btc',
      metrics: 'BlkCnt',
      start_time: startDate,
      frequency: '1d',
      pretty: true,
      page_size: daysInArrears
    }
  })
  } catch(error) {
    console.log(error)
  }

  // console.log('coinMetricsBlocksPerDay-------------------------', coinMetricsBlocksPerDayResponse.data)

  const coinMetricsBlocksPerDay = coinMetricsBlocksPerDayResponse.data

  const lastHalveningDateTime = DateTime.utc(2020, 5, 11, 19, 23, 43)

  const flow = coinMetricsBlocksPerDay.data.reduce((accum, item) => {
    const itemDate = DateTime.fromISO(item.time).toUTC()
    const blockReward = (lastHalveningDateTime < itemDate) ? 6.25 : 12.5
    const issuance = item.BlkCnt * blockReward
    // console.log(`itemDate: ${itemDate}, blkcnt: ${item.BlkCnt}, blkReward: ${blockReward}, issuance: ${issuance}`)
    // console.log(`accum: ${accum + issuance}`)
    return accum + issuance
  }, 0)
  return flow
}

export async function stock2flow(daysInArrears: number = 463): Promise<number> {

  const stock: number = 18691869 // todo: get from api

  // might be off by a few blocks since this is by day
  const production : number = await getBitcoinProduction(daysInArrears)

  const flow: number = (daysInArrears === 10) ? (production / daysInArrears * 365) : production

  const SF: number = stock / flow

  const price: number = Math.exp(-1.84) * Math.pow(SF, 3.36)

  console.log('daysInArrears:', daysInArrears)
  console.log('stock:', stock)
  console.log('production:', production)
  console.log('flow:', flow)
  console.log('SF:', SF)
  console.log('price:', price)

  return price
}

stock2flow(10)
stock2flow(463)

This outputs
daysInArrears: 463
stock: 18691869
production: 522081.25
flow: 522081.25
SF: 35.80260543737206
price: 26427.210144116314

daysInArrears: 10
stock: 18691869
production: 7618.75
flow: 278084.375
SF: 67.21653814602134
price: 219390.58584450412

But this is a far cry from the current $168,103 / $49,106 on digitalik.net/btc/ and also quite different from the daily stats telegram notification:
>> Daily stats <<
Stock/flow 10d/463d: 61 / 43
Stock/flow price 10d/463d: $159.374 / $49.216
Actual price: $55.000
Mined BTC: 18.692.706
Mayer multiple: 1,55
Days to halving: 1097
Pow law osc: 0,45
Dormant BTC >10y: 2.039.028

Yes, this is not optimized and calls the same api twice where I could cache this info. Definitely doing this in the real thing, this is for exposition only.


texts: If Bitcoin time value is 4 bytes, is that Unix time from 1970?

texts:
I assume that when January 19, 2038  rolls around, there will be a plan for extending the time to more than four bytes.
 or is it the case that the four bytes are not UNIX time, or do not begin in 1970?


texts: Would it be worth it to start mining bitcoins at this point?

texts: My budget for mining hardware is $600. Would there be an ASIC miner that I could buy for this that would return this and also net a decent amount of profit within a month or so? Is it even worth it for beginners without tons of money to invest in it now?


texts: how to use bitcoind jsonrpc for regtest or testnet server in php?

texts:
i used bitcoind with jsonrpc service.

but i added regtest=1 in bitcoin.conf at .bitcoin folder.

used:

  bitcoin-cli -regtest generate 101

  bitcoin-cli -regtest getbalance

  50.00000000

but I can't see the balance in php.

  $bitcoin->getbalance()

it doesn't show me the balance. it returns nothing.

if I remove regtest=1 from bitcoin.conf and start bitcoind -daemon.

  $bitcoin->getbalance()
  it gives me the the real server balance.

what is solution for this problem???


texts: Not sure if this is the right place to post because it is not specifically bitcoin, but it is crypto, and I need the help of someone a bit more tech-savvy than myself... I have just downloaded the wallet for a new cryptocurrency, and it was working fine, but as I was getting used to the layout, I accidentally checked “connect through socks proxy” box in the settings. Now I have tried to go back on the wallet and it won’t open, and comes up with error message “unsupported argument - socks found. Setting SOCKS version isn’t possible anymore, only SOCKS5 proxies are supported”. I have tried deleting all the files, redownloading the wallet, and restarting computer, but it still comes up with the same error message and won’t let me open the wallet to change the setting back! Is there a way to change this setting without opening the program, or bypass this error message so I can open it and change it? As this is a new currency, there is only this one wallet available so I can’t just use a different one, and I really don’t want to leave my coins sat in the exchange! Thanks in advance for any advice..


texts: What does the segwit upgrade path look like?

texts: I've been wondering what the upgrade path for the ecosystem would look like to increase the number of segregated witness transactions. What should wallets do and what should exchanges do and in what order? When do you change to displaying bech32 addresses as a merchant? When do you start being able to send bitcoin to bech32 addresses? It seems like a chicken and egg problem but presume that's because I don't adequately understand the upgrade path.


texts: How do bitcoin nodes sync with the INV mechanism?

texts:
In When and how does bitcoin node sync itself? it is described that there are a number of ways for nodes to synchronize on the blockchain state.

How does (legacy) INV mechanism works?


texts: How to calculate transaction size before sending (Legacy Non-Segwit - P2PKH/P2SH)

texts: I know that I pay the transaction fee per kB, so how can I calculate how large the transaction will be before I send it via the RPC api. I run a site using bitcoins, and I cannot let the user's balance go negative, so I need to know if they have enough balance to cover the cost.


texts:
How many bitcoins would it require for a sustained DOS attack on bitcoin network?

Without transaction fee, how many bitcoins would that be?

How many transactions could we generate with 1 BTC everyday (without fee)?


texts: Do I have access to the private key for an Instawallet?

texts: It is just numbers and letters? I have transferred my bitcoin address and want to use the key so I can move my coins from this wallet to another? As you may be aware there site is down but can I set this up on another wallet so I can still get my coins?


texts: Technical analysis of Blockchain.info security breach

texts:
I the news I read this:

  The firm was forced to make a security disclosure on its blog and on
  Reddit, admitting that a development error had led to a problem with
  the generation of private keys. Private keys (effectively the private
  addresses used to hold bitcoin) were generated with a low degree of
  entropy, making them easy for attackers to retrieve.

Is there a detailed analysis available of what exactly happened or perhaps you could share your thoughts on this? I understand a concept of information entropy just want to know what should be done and what should be avoided to achieve a high degree of entropy.


texts: How does headers-first prevent fill-disk attack?

texts:
Checkpoints prevented an attack where a node could mine many many low-difficulty blocks from an early point in the blockchain and serve those blocks to syncing nodes who would see their disks fill up. This is described in https://en.bitcoin.it/wiki/Bitcoin_Core_0.11_(ch_5):_Initial_Block_Download#Checkpoints.

Now since checkpoints are removed, we would be vulnerable to this attack. But it is stated in (https://bitcoin.stackexchange.com/a/75735/69518) that this is prevented by the newish headers-first synchronization mechanism.

How does the headers-first synchronization prevent the fill-disk attack?

A syncing node downloads all headers from a single peer. If that peer only sends headers from its malicious low-difficulty branch, won't the syncing node try to download all those blocks, and get it's disk filled?


texts: How are mutated transactions prevented from getting relayed?

texts:
Quoth Bitcoin release-notes-0.9.0.md:

  This release contains a few fixes for transaction ID (TXID)
  malleability issues:

  -nospendzeroconfchange command-line option, to avoid spending zero-confirmation change
  IsStandard() transaction rules tightened to prevent relaying and mining of mutated transactions
  Additional information in listtransactions/gettransaction output to report wallet transactions that conflict with each other because they
  spend the same outputs.
  Bug fixes to the getbalance/listaccounts RPC commands, which would report incorrect balances for double-spent (or mutated) transactions.
  New option: -zapwallettxes to rebuild the wallet's transaction information

What does "transaction rules tightened" mean and how does it prevent relaying and mining of mutated transactions?
Since mutated transactions are also valid transactions, how can the client tell original transactions apart from mutated ones?

Are powerful adversaries still able to abuse this feature after the update?


texts: What technical properties does a confirmed Tx have that an unconfirmed Tx does not?

texts:
From a user perspective, each block confirmation reduces the probability that a transaction payment will be reversed.

However from the perspective of the software, what happens when a transaction is confirmed? For example, I know it is removed from the mempool. Is there any other technical difference between confirmed and unconfirmed transactions? Are both outputs stored in the same UTXO set? Does anything happen on any lower level (data storage, etc) inside a node or on the network or in the protocol once a Tx is included in a block?

Do confirmed transactions have any special properties besides the human perception of safety?


texts: How do I get my Ravencoin wallet address on Ravencore?

texts: Very new to this, and couldn't find help on Google.


texts: No idea what wallet site, or password(s) but has the old computer

texts: My friend was paid out in bitcoin approx 2 years ago, she has no idea what wallet site, password(s) but has the old computer still. Is there a way to find enough data to recover her Btc? She is and was clueless about btc, wallets, etc...  I practiced looking on my computer after briefly searching the net and couldn't find a wallet.dat file. Went back to work searching the net and found this site first thing.


texts:
Is it possible to include a blank input in a transaction?

For example, a blank input could be used to guarantee a particular output was included in a transaction, using SIGHASH_SINGLE | ANYONECANPAY in combination with SIGHASH_NONE.

Of course you would still need to include miner fees within another input.

Correct me if I am wrong, but although spending 0-output utxos is legal, it is fairly difficult to generate 0-output utxos, as Bitcoin Core does not support generating these transactions beneath the dust limit.

Likewise, OP_RETURN provides 0-value-output utxos, but they could not be spent as part of a sighash_single, since they are unspendable.


texts: Why does the mined block differ so much from the block template?


texts:
I have been running a full node for little less than a year and I am following the discussion around blocksize increase. I am for it.

Who actually can make a decision whether  the blocksize increase gets committed to the bt core? Is a majority vote from core devs required? Obviously Gavin Andersen, an outspoken core developer is trying to convince someone with his blog posts. Whom?

Also how can the public coordinate their desire for blocksize increase? Everyone posting in their blogs is not going to cut it, or?


texts:
In the Ripple system we have two types of currencies - ripples and all other currencies useful for transacting with people in your web of trust. Ripples are the only currency in the system that can be used for paying transaction fees and transactions between any two users even if they are not connected.

With the discrepancy between the supply of ripples and the size of the fees, spamming the system would be virtually free. This usefulness of ripples is thus moot. Trading between any two peers could be accomplished with Bitcoin, so this use is also limited.

So, with that in mind, what use are ripples really, asides being a way for the developers of the system to monetise?


texts: Is there a limited number of addresses a wallet can hold?

texts: Let's say I have an imported-type electrum wallet, how many private keys can I import to that wallet, if there's a limit to it?


texts: Please can someone explain if this is a  genuine app for bitcoin mining?


texts:
I recently downloaded a Bitcoin core wallet. I have been using it perfectly fine for a few days.
I have the wallet on a portable hard drive with my mac.
The wallet syncs up perfectly fine on opening my mac.
I just created a backup dat file.
I have also just encrypted my wallet. It now shows as locked.
When I try to open my wallet using the dropdown tab. The spinning timer icon appears.
I have tried a couple of times and even shut down my machine.
However the issue remains.
The timer just reappears as soon as my mouse arrow hovers on it.
If anyone can help me with this issue it would be greatly appreciated.
Thank you.


texts: Multibit HD: how much fee for cheap way to transfer bitcoin to other wallet?

texts:
I have 0.015161 BTC in my Multibit HD wallet and now I want to move them all to Electrum wallet. So, how much fee to set for this transaction as a cheap way?
And how long I must wait?
The default value I see in Multibit HD is 0.0005 BTC/kb


texts: guide is for a single masternode, on a Ubuntu 16.04 64bit server (VPS) running headless and will be controlled from the wallet on your local computer (Control wallet)


texts: Why were private keys made unrecoverable?

texts:
Why were lost bitcoin private keys made unrecoverable?

Is there a way to do this and if not shouldn't a way be created since people will lose their money.


texts: Possibility to retrieve BIP39 mnemonic (24 words English dict) from BIP39 (hex) seed?

texts:
I am in a situation where I have access to a BIP39 hex seed which I know has been derived from a BIP39 24 word English dictionary mnemonic.
I would like to retrieve this 24 word list - is this possible?
As far as I know there is no hierarchy per se between hex seed and mnemonic, so they should be bijective (hopefully).


texts:
I went to https://siminchen.github.io/bitcoinIDE/build/editor.html to try some bitcoin scripting and I wrote this script:

<1PUzZ61FSVTn12CafJC85Vy1ts3BoFcXdU> OP_HASH160 <E105E01B92119CC55D753248CE3A32C82A9BB308> OP_EQUAL

Screenshot:

My script fails even though both the hashes are same. Why?


texts: Who would benefit from Taproot deployment?

texts:
In the discussion of activation parameters for Taproot, a Bitcoin Core contributor stated that "Taproot would only benefit 5% of the users" citing that it would especially benefit complex scripts. I've seen that statement immediately picked up to ridicule Bitcoin development as only being for the benefit of Blockstream.
I thought that Taproot would be beneficial to most users. Is it accurate to say that it will only benefit 5% of the users?


texts:
i downloaded Bither as my virtual wallet and added bitcoins in a Hot Wallet Address. But when i try to send bitcoins, i can't.
i fill the address, the amount of bitcoins and i type my password but the button "send" is colored on light grey and i can't click on it.

So i would like to know how to send bitcoins with Bither, and if i can't, can i switch my wallet to another software ?

Thanks by advance :)


texts:
What is the distribution plan to get Ripples (XRPs) distributed to the general public? How will hoarding / spoofing be tackled?

(E.g. with a faucet based on Google account auth, one could open several google accounts and get "too many" XRPs).


texts: Missing transactions with blockchain.info

texts:
All of the quick send transfers I've made on blockchain.info do not show up in my blockchain.info history.  Furthermore, a person I have made a few quick send transaction with is claiming 0 confirmations on them.  And the transaction ids he recorded for these don't exist in blockchain.info's history of transactions.  These bitcoins have been deducted from my blockchain.info wallet, though.

1) Will these ever get confirmed?  If so, when?  If not, how do I get my bitcoins back?

2) Why aren't they showing up as transactions in blockchain.info?


texts: Problem caused by unconfirmed transaction chains

texts:
I want to build a service that requires sending many small bitcoin transactions to multiple wallets (like a faucet).

Since the transactions are small, the fees have to be kept small as well so it takes a while for them to be confirmed.

The system would need to send many transactions, which naturally creates long chains of unconfirmed transactions. If I understand it correctly, after 25 unconfirmed transactions the network starts rejecting new ones, and the system is basically stuck until the previous ones gets confirmed.

This limits the throughput of such a system to 25 transactions per confirmation time (which is at least a few hours given the low fees), making it completely unscalable.

Given the above, is there a way to build a (somewhat) scalable service that can send many small transactions? (without having to manage many wallets)


texts: How to use UTXO of xpub derived addresses?

texts:
I'm new in Bitcoin, this is something I'm confused with.
If we are deriving children, i.e. public keys, from xpub, without private keys, for the purpose of receiving outputs, how are we able to spend UTXO if we don't have private key?
In this example:
https://github.com/bitcoinbook/bitcoinbook/blob/develop/ch05.asciidoc#using-an-extended-public-key-on-a-web-store
xpub is set up on server to generate public keys to receive money on e-commerce website. But how do we access that money if we don't have private keys?


texts:
While trying to sync I got a "block checksum mismatch" in my debug.log file. Here is the last 30 lines. You can see that it happily downloading block, then it gets a network unreachable, then it has a fatal error:

2017-02-13 12:23:13 UpdateTip: new best=000000000000000005f83797c139814ac19f6df01ddb5a366ad0a8889eea9e4c  height=409620  log2_work=84.577937  tx=125928733  date=2016-04-30 20:50:36 progress=0.848096  cache=37.2MiB(19128tx)
2017-02-13 12:23:14 socket send error Socket operation on non-socket (88)
2017-02-13 12:23:14 connect() to [2a02:180:6:1::109]:8333 failed: Network is unreachable (101)
2017-02-13 12:23:19 UpdateTip: new best=0000000000000000020227bef01de871ccb17e3f6b9a86e9a2785001a71c6afe  height=409621  log2_work=84.577975  tx=125929755  date=2016-04-30 20:57:19 progress=0.848099  cache=64.3MiB(21625tx)
2017-02-13 12:23:23 Corruption: block checksum mismatch
2017-02-13 12:23:23 *** System error while flushing: Database corrupted
2017-02-13 12:23:23 Error: Error: A fatal internal error occurred, see debug.log for details
2017-02-13 12:23:23 ERROR: ProcessNewBlock: ActivateBestChain failed
2017-02-13 12:23:23 tor: Thread interrupt
2017-02-13 12:23:23 opencon thread interrupt
2017-02-13 12:23:23 addcon thread interrupt
2017-02-13 12:23:23 torcontrol thread exit
2017-02-13 12:23:23 scheduler thread interrupt
2017-02-13 12:23:23 net thread interrupt
2017-02-13 12:23:23 msghand thread interrupt
2017-02-13 12:23:23 Shutdown: In progress...
2017-02-13 12:23:23 StopNode()
2017-02-13 12:23:23 Corruption: block checksum mismatch
2017-02-13 12:23:23 *** System error while flushing: Database corrupted
2017-02-13 12:23:23 Error: Error: A fatal internal error occurred, see debug.log for details
2017-02-13 12:23:23 Shutdown: done

What is the problem?


texts: Does Bitcoin Gold automatically appear in my ledger nano s wallet?

texts: How do I get Bitcoin Gold into the Ledger Nano S Bitcoin Gold (Segwit) wallet?


texts: Bought a used ledger nano s from Amazon / Ebay. How do you factory reset the Ledger Nano S?

texts: I just bought a used ledger nano s from amazon and ebay. What is the best method of wiping this device and factory reset it? What are some other precautions before using this used device?


texts:
Should I use a different address for every transaction? If yes, why? For safety?
What happens I use the same address to get bitcoins from 2 different people, what happens?


texts: Is a mined block invalid as soon as another block is added/accepted?

texts:
If all the miners are working on adding to the central blockchain, what happens if a miner (A) submits their valid block just seconds after another miner's block (B) has been accepted and added to the chain?

Since the new hash-value of the last block in the chain changes with the newly accepted block (B), does that make the computed hash (A) invalid?


texts: Calculating total outgoing transaction fees associated with a single address?

texts:
I'm building an app to display information pertaining to individual Bitcoin addresses.

I've been using the blockchain.info API to get data regarding the final_balance, total_received, and total_sent.

But I'm having a little trouble figuring out how to retrieve data on transaction fees.

Looking at the json when querying an address (for example 1CK6KHY6MHgYvmRQ4PAafKYDrg1ejbH1cE) I'm assuming I would need to iterate through the hash of transactions it returns, and use the hash of the transaction with the value "result" > 0?

I'm just not certain how to differentiate between spending and receiving when looking at the json.


texts: I was on a site www.realgg.nl last night, they have some attractive funding options for me because I live in UK it's difficult to get coins. (Well a lot more difficult than US). Just wondering if anyone knows whether it's legit.


texts: It's only a question, i don't want to mine solo, knowing that it's not efficient, but since Bitcoin Core 0.13.0 how do we mine solo? (using rpc maybe?)