texts: When the last Bitcoin block is mined, how would transactions continue?

texts: If transactions are stored in Bitcoin blocks through Merkle trees, when the last Bitcoin block is mined, how would there be future Bitcoin transactions? Where would those transactions be stored on?


texts: Jump straight to the asset trading page on Ardor Ignis via a shared url link?

texts: Is there a way to jump directly to the asset trading page in Ardor without logging in? Just by using a shared url link.


texts: I need to display at my website what a certain amount of Bitcoins will likely cost. I can fetch the latest price using the MtGox API and multiply it by the amount, but for large amounts this is inaccurate because the buy itself will move the price. The only other option seems to fetch the whole orderbook, and calculate it myself each time, but isn't there an API for this?


texts: In btc network does the limit of Vin should be less than 1000 in for a single transaction?

texts: Suppose i am doing transaction which involves more than  50k Vins. I found that i cant do thaat in a single go. So is it true that even if the size of block is less than the maximum limit, i cant do that transaction because of limit in Vins?


texts: How can I calculate how long it took a transaction to be confirmed?

texts:
Is it possible to calculate - or even reasonably estimate - how long it took for a transaction to be included in a block after it was first created?

I'm asking about already confirmed transactions which are already included on the blockchain - and all transactions - not just ones that belong to me.

I am currently building a project which scrapes a given blockchain for whatever info/attributes a user desires. You can check it out here - be warned it's no where near ready for production and not even at version 1 yet - but the develop branch is getting close.

As I understand from the docs and the answer to this question the time received attribute is not, as some may think, the time a transaction was "received into a block" but rather the time when my client first noticed the transaction - this attribute is also not available when using getrawtransaction. So that's a no-go.

Ideally, I'm looking for the time that a transaction is created (sent) and the time it is included (confirmed) on a block.

Based on the above info my idea is:

for new (unconfirmed) transactions we record the time that my node
first notices the transaction
then we record the time that my node
notices it is confirmed

This would at least give me an indication as to how long it takes newly created transactions to be confirmed. Of course latency adds a huge amount of noise here, but it's at least a step in the right direction!

I would like to do this for existing, confirmed transactions if possible.

Thanks for your time.


texts: Installing insight blockchain explorer - is bitcore mandatory?

texts:
What I have: bitcoind on Linux running.
What I want: to have insight api+ui local website running.

Earlier it was possible to add insight querying your bitcoind. Now it seems they made some bitcore base for insight.

If I install bitcore is it gonna replace bitcoind? How do they interact?

What's the best way to have local insight explorer running now?


texts: I want withdraw from BitPay and send USD to bank account in Puerto Rico. I reside in Argentina. Is that possible?

texts:
I want to withdraw/sell bitcoins that I have on my BitPay wallet. I need to transfer the results USD to account in Puerto Rico. I reside in Argentina.

I have already tried with Skirll, but does not allow Puerto Rico bank account.


texts:
I read somewhere that as older a bitcoin become as higher exchange fees the buyer has to pay. Is that correct?  These exchange fees go to the miners only or to whom else?

thank you


texts: How public key is calculated from a base58 encoded private key?

texts:
I followed this post and created a private key for bitcoin wallet. The post says after finding the random 256 bit(32 bytes) integer the version number should be prepended and the checksum should be appended to it. This produces a 37 bytes hex.
Now I am trying to find the public key associated with this private key.I learnt that the PUBLIC key is calculated by applying ECDSA secp256k1 curve on the private key. But only 32 bytes is accepted as input by the ECDSA algorithm.
So what am I doing wrong?
Thanks in advance.


texts: Altcoin creation from bitcoin ReadBlockFromDisk: Errors in block header at CBlockDiskPos

texts:
I am trying to create a altcoin using bitcoin source code.

i have changed the pszTimestamp, port number, magic number. I have cleared the DNS seeds and removed checkpoints for now.
Then I printed the following values using printf and updated the new values:
genesis.hashMerkleRoot and genesis.hashMerkleRoot

In the log file I see this error:

  2017-10-04 18:32:29 ERROR: ReadBlockFromDisk: Errors in block header at
  CBlockDiskPos(nFile=0, nPos=8) 2017-10-04 18:32:29 *** Failed to read
  block 2017-10-04 18:32:29 Error: Error: A fatal internal error
  occurred, see debug.log for details

I tried to debug the code and i see that this is where it fails in pow.cpp :

 bool CheckProofOfWork(uint256 hash, unsigned int nBits, const Consensus::Params& params) {
      bool fNegative;
      bool fOverflow;
      arith_uint256 bnTarget;

      bnTarget.SetCompact(nBits, &fNegative, &fOverflow);

      // Check range
      if (fNegative || bnTarget == 0 || fOverflow || bnTarget > UintToArith256(params.powLimit))
      {
          LogPrintf("\ncase 1\n");
          return false;
      }
      // Check proof of work matches claimed amount
      if (UintToArith256(hash) > bnTarget)
      {
          //LogPrintf(bnTarget);
          LogPrintf("\ncase 2\n");
          return false;
      }
      return true;
 }

It prints case 2. What does this mean? What am I missing?


texts: BlockChain.info Investments? Sounds like a scam

texts:
Today I received a strange email, which looks like a scam to me. It claims to be sent from blockchain.info no-reply@blockchain.info, but being a programmer, I know that I can send email from whomever I want, so I do not trust it so much.

  Welcome to BlockChain.info Investments, a place of stable income.

  This email is sent to all Bitcoin members. If you are not Blockchain
  user, you can still invest with us. All you have to do is choose
  amount you want to invest and send it to Bitcoin address below.

  Minimum investment is 0.1 BTC or 50$ USD More you invest, more you
  earn.  This is not a ponzi, we are paying our valuable members from
  advertising money and fees.  This Investment option will be available
  for limited time only.

  Example: Invest 0.1 BTC - 1 BTC - Receive 105% after 1 day. Invest 1.1
  BTC - 2 BTC - Receive 110% after 1 day. Invest 2.1 BTC - 5 BTC -
  Receive 115% after 1 day. Invest 5 BTC or more and receive 120% after
  1 day.

  For example if you invest 1 BTC, you will receive 1.05 BTC after 24
  hours. Invest 10 BTC and receive 12 BTC after 24 hours.

  Payments will be made automatically 24 hours after you send money. You
  will receive email confirmation after you send money to our Bitcoin
  address for investments.

  When you are ready to invest, choose amount and send it to this
  address below. 1LFHVdwAV9w994sMi6o1JpJeykZhdbGfpn Every user will
  receive custom address for deposits and withdrawals.

  Blockchain Team.

I formatted it a little bit, but basically this is it. Also this does not look like a ponzi scheme to me, it looks like a scam. Moreover I haven't found any information about blockchain investments on their site (but I admit I have not looked too much).

My question is: is this a real thing?


texts: Bitfinex get credits and convert timestamp to JS Date

texts:
I'm fetching my active credits in BFX and trying to discover when I'll have my funding back. This is a response example:

/v1/credits

[{
    amount: "294.4316181",
    currency: "USD",
    id: 15778083,
    period: 2,
    rate: "16.816",
    status: "ACTIVE",
    timestamp: "1454846632.0"
}, ...
]

But new Date(1454846632.0) returns a very old date, what makes me think this timestamp isn't there to be converted into a real date at all.

I am doing something wrong? How can I discover the remaining time of a credit I provided?


texts: Did BitGo terminate its "BitGO instant" service? Why?

texts:
This is the launch announcement.

https://www.bitgo.com/instant is a dead link now.


texts: Portability of Bitcoin Wallets: What If The Power Or Network Is Out?

texts:
My understanding is that the blockchain is public and contains balances (or the monetary value) and that a private key, or a wallet, enables one to control or spend bitcoin.

If my wallet (private key) is stored on a small USB stick, can I purchase anything using bitcoin if there is no power/network near me?


texts: Have bitcoin developers applied the solution for selfish miner attack?

texts:
The Majority is not enough paper proposed an academic and somehow practical attack to Bitcoin mining system based on creating hidden forks. The paper claims that if miners work on whichever fork they received first, the attack can be executed by very small pool. Their proposed solution is: "when a miner learns
of competing branches of the same length, it should choose which one to mine on uniformly at random". However this solution does not solve the problem completely, it just increases required size of the pool which want to execute the attack.

I have read about the attack here and here, however, I didn't find answers of my questions:

Is the attack really practical?
Have bitcoin developers applied the solution proposed in the paper? (If yes, why the wiki is not updated? The wiki states: "generating nodes build onto whichever one of the blocks they received first")
Have bitcoin developers applied another solution for the problem? (The solution proposed in the paper does not solve the problem completely)

EDIT:

why mining on both chain forks uniformly would increase the required mining power for a selfish mining attack?

Mining on both chain forks uniformly is a solution to sybil attack of the selfish miners. Selfish want to force other miners to work on their fork, so they create a significant number of zero-power miners to the Bitcoin miner network, as their sensor. When one of their sensors senses a new valid block, all sensors broadcast the fork of the selfish miners. Therefore, more than half of miners (nearly all of them) would work on selfish miners fork.

Note that, the sybil attack and their proposed solution is minor part of the attack. The main attack could be executed without running sybil attack and even in the case of applying their proposed solution, if the selfish miners have 33% of mining power.


texts: Sending coins from Multibit stuck at "Unconfirmed / Pending"

texts:
I bought some bitcoin in 2013 and stored it in my Multibit wallet (0.5.16). I am trying to convert my bitcoin into USD.

First, I found that I was running an old version of Multibit, so I attempted to upgrade to MultibitHD as instructed here. I sent a small amount of bitcoin (0.0001) to the MultibitHD wallet, which remained unconfirmed / pending, with no record on blockexplorer.

My understanding, which please correct me if I'm wrong, is that since I'm sending the bitcoin, there's no difference between sending them to a new wallet provided by MultibitHD, and say a Coinbase wallet. So, since I want to sell these things, I figured I'd try cutting out the middleman and sending directly to Coinbase.

I upgraded Multibit Classic to 0.5.19, and then sent 0.0001 bitcoin to my Coinbase wallet, and it appeared (pending) in Coinbase. Great, so I then sent the rest of my bitcoin, only to see a "square" in Multibit Classic, no record on blockexplorer, and just unconfirmed / pending.

Freaking out a bit, I looked over this answer, and this Multibit FAQ and surmised that, since Multibit Classic automatically calculates the fee (I believe it was 0.0001 BTC, or around $0.10) it must be a network issue. I then did a "Reset blockchain and transactions", and when that completed my transactions were cleared of the unconfirmed transactions, but my wallet balance was at 0.

Luckily, I had a backup. I booted that sucker up and my bitcoin balance was back to where it was, synchronized with the network, with no record of those transactions (also no record of the Coinbase transaction, which is confusing). I upgraded Multibit Classic to the latest release, 0.5.19, and sent 0.0001 bitcoin to MultibitHD. It appeared successfully. I then sent another 0.0001. This gave me (another) square with unconfirmed / pending.

I'm now sort of at a loss as to what to do, and feel like I'm playing with fire without a strong understanding of what's going on.

To recap:

I want to convert my bitcoin from a Multibit Classic wallet into USD.

I sent 0.0001 BTC from Multibit 0.5.16 to Multibit Classic, was
stuck in unconfirmed / pending state
I sent 0.0001 BTC to Coinbase, then the rest of my BTC. First transaction worked, second stuck in unconfirmed / pending state.
I sent 0.0001 BTC from Multibit Classic to MultibitHD, twice. First transaction worked, second stuck in unconfirmed / pending state.

My best guess is that the fee I'm paying is not high enough; but there seems to be no way to set the fee in Multibit Classic. I would gratefully appreciate any help as to what I'm doing wrong here.


texts:
If I have to make 10 payments of various amounts to different recipients:

What is the best approach for the lowest tx fee? One transaction that will serve many (or all) logical payments (many inputs and outputs) or many but small in size transactions that will each serve a single logical payment?
Which of the above transactions is most likely to get completed successfully? In the combining transaction, if a sub-payment fails after the transaction has been broadcasted to the network will all of the other sub-payments fail and will the transaction never confirm?


texts: add mysql dependency configure.ac bitcoin

texts:
i am working on bitcoin code, my aim is to move blockchain data to relational db but i am not able to resolve mysql dependency for different platform, platform includes mac and ubuntu. I have tried giving static and dynamic dependency but both of those things not working at all.

 [  --with-mysql=<path>     root directory path of MySQL installation],
    [MYSQL_lib_check="$with_mysql/lib/mysql $with_mysql/lib"
MYSQL_inc_check="$with_mysql/include/mysql"],
    [MYSQL_lib_check="/usr/local/mysql/lib/mysql /usr/local/lib/mysql /opt/mysql/lib/mysql /usr/lib/mysql /usr/local/mysql/lib /usr/local/lib /opt/mysql/lib /usr/lib"
MYSQL_inc_check="/usr/local/mysql/include/mysql /usr/local/include/mysql /opt/mysql/include/mysql /usr/include/mysql"])

AC_ARG_WITH(mysql-lib,
    [  --with-mysql-lib=<path> directory path of MySQL library installation],
    [MYSQL_lib_check=$with_mysql/lib/mysql])

AC_ARG_WITH(mysql-include,
    [  --with-mysql-include=<path>
                          directory path of MySQL header installation],
    [MYSQL_inc_check=$with_mysql/include/mysql])

AC_MSG_CHECKING([for MySQL library directory])
MYSQL_libdir=
for m in $MYSQL_lib_check; do
        if test -d "$m" && \
       (test -f "$m/libmysqlclient.so" || test -f "$m/libmysqlclient.a")
        then
                MYSQL_libdir=$m
                break
        fi
done

while configuring i was trying to gave path of installation directory i.e ./configure --with-mysql=/path it configured successfully but when i execute make command it throws exception "_get_driver_instance", referenced from: makeConnection() in libbitcoin_wallet.a(libbitcoin_wallet_a-walletdb.o)

might be i am not on right track, help me if you have any idea regarding make file system

any help is appreciable, thanks.


texts: A common criticism of Segregated Witness is that it is "unnecessarily complex". Why is it chosen over alternatives?

texts:
Segregated Witness (SegWit) is well-along the way to being implemented and deployed as a soft-fork.

Facts:

SegWit eliminates most forms of transaction malleability.
Discounts input scripts in comparison to other block content.
Adds a new function/constraint to the Coinbase transaction by requiring it to contain the root of the SegWit data.
Provide a capacity increase upon adoption.
Makes future changes to Bitcoin Script easier.

Questions:

What other methods could achieve the above benefits?
Why was Segregated Witness chosen instead?
Is there an alternative that is less complex to introduce when regarding the complete picture, i.e. technical, economical, and social aspects?

Intent: The above is a criticism that is frequently stated in parts of the Bitcoin community, and I hope to provide an anchor for a visible collection of expertise on the matter.


texts: 2 bitcoinqt - getrawmempool returns different results

texts:
I have 2 servers with running the same Bitcoin Core v0.9.3.0-g40d2041-beta (64-bit).
I use getrawmempool to get all new transactions in the same time but I have different result. One server always have more transactions. Difference quite big - about 10%.

Why?

I am trying monitor all new transactions for some reasons and this difference means for me that getrawmempool not is not good way for this.


texts:
I've read that some mining pools disappears all of a sudden, and your hard earned coins also disappear if you didn't transfer them ontime.

My question is, how do you go about picking a pool which isn't going to disappear?

I've not done mining before, but want to try out litecoin mining.

Or is it better for me to start mining without using a pool if that's possible?


texts: electrum get transaction amount command line

texts: How to retrieve transaction amount via command line? Seems gettransaction return hash which contains only some inputs outputs info without any amount.


texts: Is it possible to split a key for transaction signing without using multisig?

texts:
I am developing a wallet API, but I don't want custodial control of the user's funds.  For reasons I won't explain here, I don't want to use multisig.

But I want the advantages of a 2 of 2 multisig.  I want the client to sign a transaction, and then send that signed transaction to the server.  The server will then finish signing the transaction and push it to the network.

Is this theoretically possible?  Does something like this exist yet in practice?

In summary, I want a way for the client and the server to sign a transaction together without either one having the private key.


texts: Tracing Bitcoins to their original blocks

texts:
Can I find (always, without fault) the specific set of blocks from which the Bitcoins that I hold originated?

If yes, would such a trace-back be computationally costly?


texts: Does the bitcoin design make bitcoins suitable as a medium of exchange, a store of value, or both?

texts:
Money is often seen as having various functions, such as "medium of exchange" (something useful for conducting transactions, and "store of value" (something valuable as an investment).

Was bitcoin designed to provide both functions, or just one?  How does it mainly function today?


texts: Running bitcoin node in docker behind NAT

texts:
A running bitcoin node doesn't accept incoming connections when it's running behind NAT in a docker container.

To confirm the problem is related to docker I edited NAT settings on my router. If router's WAN port 8333 redirects to a machine running full node as a process incoming connections are possible. But if WAN port 8333 redirects to a machine running full node in docker container - I get inaccessible from outside bitcoin node.

To test accessability that I used this URL https://bitnodes.earn.com/#join-the-network (the website auto detects your external IP address and auto fills the box; only thing left is to press the button). If the node is accessible the test finishes green, if not - red.


texts: export Bitcoin Cash private key from Bitcoin QT after send out BTC to exchange

texts:
After Bitcoin Cash folked,  I have sent BTC to exchanges from wallet Bitcoin QT. Before sending, I have export out a file with format as below in .CSV file:
Confirmed,Date,Type,Label,Address,N,ID
TRUE,2017-07-30T21:25:50,Received with,tes,X_address,X_number_of_bitcoin,X_ID

I thought the X_ID is the private key at that time. However, when I tried import X_ID into another BCH wallet, the error message said: the format is not correct. I appreciate anybody's help in term of how to get the private key  at this point.


texts: Testnet: mandatory-script-verify-flag-failed when doing OP_RETURN

texts:
For some reason I keep getting error: {"code":-25,"message":"Missing inputs"}

EDIT: Updating error now that the full testnet blockchain is downloaded

"code":-26,"message":"16: mandatory-script-verify-flag-failed (Operation not valid with the current stack size)

I am not sure why I am getting this error. Can someone help me debug or point me in the right direction ?  Using TESTNET3

0100000002f739b61642740a6f9b24859a30cf5f248722e9dd8f38f981e5d8a7c1f16354350100000000ffffffff0a31a52da8f2fc706d15025810eca7b6bfa53bdabcc5feefc5d55e1d2f728a170000000000ffffffff0290333200000000001976a9141ce00dca082ca1215c9e5a7a3237d267124fea3288ac00000000000000001a6a1857485920546573746e65742067697665206d65207061696e00000000

{
"Version": "1",
"LockTime": "0",
"Vin": [
    {
        "TxId": "355463f1c1a7d8e581f9388fdde92287245fcf309a85249b6f0a744216b639f7",
        "Vout": "1",
        "ScriptSig": {
            "Asm": "",
            "Hex": ""
        },
        "CoinBase": null,
        "Sequence": "4294967295"
    },
    {
        "TxId": "178a722f1d5ed5c5effec5bcda3ba5bfb6a7ec105802156d70fcf2a82da5310a",
        "Vout": "0",
        "ScriptSig": {
            "Asm": "",
            "Hex": ""
        },
        "CoinBase": null,
        "Sequence": "4294967295"
    }
],
"Vout": [
    {
        "Value": 0.0329,
        "N": 0,
        "ScriptPubKey": {
            "Asm": "OP_DUP OP_HASH160 1ce00dca082ca1215c9e5a7a3237d267124fea32 OP_EQUALVERIFY OP_CHECKSIG",
            "Hex": "76a9141ce00dca082ca1215c9e5a7a3237d267124fea3288ac",
            "ReqSigs": 1,
            "Type": "pubkeyhash",
            "Addresses": [
                "mi9dcxfvGTsDCs46UZXXYQ8JH5MLcGxMxz"
            ]
        }
    },
    {
        "Value": 0,
        "N": 1,
        "ScriptPubKey": {
            "Asm": "OP_RETURN 57485920546573746e65742067697665206d65207061696e",
            "Hex": "6a1857485920546573746e65742067697665206d65207061696e",
            "ReqSigs": 0,
            "Type": "nulldata",
            "Addresses": null
        }
    }
],
"TxId": "998221ecf0e85c1b3f1e06fbdfd5bb6b2957c244fcdbb8a2e2a8ad9b3270d440"

}


texts:
I have been gifted a paper wallet prior to the BTC/BCH fork. I have set up a Blockchain account and a Coinbase account (both empty at this time) on my computer and my tablet.  Do I need 2 accounts each, one for BTC and o.ne for BCH.
I'm still struggling with the procedure to empty the paper into the Blockchain.  I suppose this goes first into the tablet as an electronic wallet?  Thought I was computer savvy but this is tasking me!!!
Any help will be appreciated.


texts: How to communicate between Java and bitcoind?

texts: I am having problems communicating between Java and bitcoind - every JSON RPC library I try has some issues. Can anyone provide a working implementation of even the most basic JSON RPC communication between Java and bitcoind ?


texts: With Mike Hearn quitting Bitcoin, what seems to be the future of bitcoinj?

texts: Mike Hearn has apparently sold all his Bitcoins. So what is to be expected about the development of bitcoinj? (and Java based clients in general).


texts: Is the Trusted Third Party an advantage or disadvantage in regards to wallet security?

texts:
I'm new to bitcoin and have been reading some intros and FAQs.  Most features of bitcoin seem better than our current currency systems.  However, the one thing that strikes me is the ability to have your wallet stolen.  Either through malware, keylogger, in person, etc.  I've reading some posts on here about securing your wallet.  But the fact remains that it could get stolen.  And if it gets stolen your bitcoin balance is gone.  There is no way to recover it.  If you compare that to credit cards, when your card (or card number) gets stolen, the thief may make payments using the card, but the trusted third party (bank or credit card company) will usually not hold you liable and refund the money.
Therefore, if bitcoin were to become the most widely used currency in the world, people could lose their life savings just by a single virus infection or devious hacker.  Having that bank or credit card company involved provides that extra level of shelter.
Does anyone think this will hold back bitcoin use from becoming widespread throughout the world?


texts: When I use bitcoin-cli getnewaddress "" "p2sh-segwit" which kind of script is inside And can I convert if in bech32?


texts: A Bitcoin locking script to force a certain payment to the receiver?

texts:
Is there a way to use Bitcoin script to force payment for the receiver?
I do not mind if it's a non-standard transaction, just curious if Bitcoin script itself allows expression of something like that.
For example, is it possible to write a locking script such that:

Alice sends 1 BTC to Bob
But Bob can ONLY spend if Bob sends 0.5 BTC to Carol in the next transaction


texts: Regular Expressions for DER signature hex (also req, address, TxIDs)?

texts:
I'm using Python (2.7) and its re module for recognition of various Bitcoin data, namely:

  addresses, DER sigs, OP Return hexdata, TxIDs

I've been using re.compile: for example, for a valid Tx hash (TxID):

RE_TXHASH = re.compile('^[0-9a-fA-F]{64}$')
if bool(re.match(RE_TXHASH, 'f'*64)):    # 'f'*63 would fail
    print 'valid tx hash!'
else:
    raise Exception("invalid tx hash!")

I'm looking for regex patterns for the following (or input on my current best attempt):

DER signatures: General format "30[sig_size]02[r_size]02[s_size][sighash]"
Bitcoin addresses:  re.compile('^[123mn]{1}[a-km-zA-HJ-NP-Z0-9]{26,33}$')
OP Return hex strings: re.compile('^(6a){1}[a-fA-F0-9]{0,80}$')
TxIDs: re.compile('^[0-9a-fA-F]{64}$')

EDIT: to clarify, can someone help with a regex pattern for this? "30[sig_size]02[r_size]02[s_size][sighash]"


texts:
After generating a 2-out-of-3 wallet (using brainwallet http://ms-brainwallet.org/#generator) I am able to store my private/public keys for each of the participants.

Afterwards I send a small amount of BTC to this address (0.0002). The amount is correctly recorded and confirmed in the blockchain and is listed as an unspent transaction.

Afterwards I create a new transaction that spends (0.0001 BTC). This transaction is successful. On the third step I sent more funds to the 2-out-of-3 wallet (0.0003). This is where the issue happens: any funds I deposit in this wallet from second transaction on are automatically spent towards various unknown addresses, and there is never any unspent transactions no matter how much I deposit there.

I have tested this with several wallets already.

What I am thinking of is that there is a change problem. I found some ways that funds can 'evaporate' but I haven't been able to nail the issue completely. Any inputs would be appreciated.


texts: How do pool server's handle multiple workers sharing one connection with Stratum protocol

texts:
The stratum protocol supports authorizing multiple workers in a single connection. Unfortunately, I didn't find any documentation about how this should be handled by pool server software.

If multiple workers share the same extranonce1 (which is a per-connection unique string), wouldn't the workers duplicate work? Is this to be handled by the client?

Do all the workers use the same job_id for share submission?

Should a server send a job notify when the second, third etc. worker successfully passes authorization?

And finally, does anyone actually use this (multiple workers per connection) and for what purpose?


texts:
Can a Bitcoin block be less than 1mb?

To my understanding, a miner receives broadcasts. However, if not enough transactions come in, then would it just prematurely hash the block?


texts: Unconfirmed balance in MultiBit HD plus unconfirmed transactions (failed bitpay orders)

texts:
I've had a little bit of BTC in a MultibitHD 0.5.1 wallet for a while now. With the latest surge in price, I tried spend it at a place that uses bitpay. My first transaction probably had too little of a fee and is unconfirmed. I attempted to redo with a larger fee but it too told me was too small a fee and my attempt to buy from the store failed.

After some searching I found that Multibit is not good to use anymore / discontinued. I also came across something telling me to repair the wallet which I did but then the remaining balance became unconfirmed and not sure what to do next.

How could I get back the unconfirmed balance or confirm it? Is there anything I can do about my two unconfirmed transactions? Would it make sense to transfer everything to a new wallet software (can't when unconfirmed balance)?


texts: What were the dates of Bitcoin's previous price plummets prior to 2015? What articles were written about it?

texts:
As of Jan 2015, the price of Bitcoin has plummeted from 300ish to 200 since the summer of 2014. This wasn't the first time happening to have the price plummet in such a state where mass media starts reporting "the death of bitcoin".

What were the previous dates and percentage drops in USD that caught mass media attention prior to 2015 Jan?
What were some of the articles that were reported on these dates believing that Bitcoin is about to die? And by whom?


texts: What is the difference between deleting a private key and deleting an address?

texts: On Blockchain.info, when deleting private keys from your wallet, it asks if you want to delete only the private key or if you want to delete both the private key and the address. If you choose to delete the address in addition to the private key, does this mean that unless the address is generated again, it doesn't exist anymore? If not, what does it do?


texts: My Multibit wallet stops updating and says another program has changed files. How can I solve this?

texts:
I am running Multibit on Windows 7. When I open it, the synchronization will initially start, but then stop after a while due to "another program attempting to change files".

I didn't move any files while it was running. I have also tried updating MultiBit, but the same error occurred again.

What could cause this error and how can I resolve it?


texts:
I am trying to built an application that uses the BIP-32. But I am not sure on how to use it.

I have a passphrase with which I generate the Derived Private Key and Derived Public Key. If I share my Derived Public Key with a second wallet will the wallet be able to generate others Derived Public Key from it ? Is it possible ?

And since I have the original Derived Private Key with me, can I see what is happening in the second wallet ?

Also if I loose both the Derived Private Key and Derived Public Key, will I be able to recover my wallets using only the Passphrase ?


texts: How are "message signatures" verified without having access to the public key?

texts: In the bitcoin-qt client you can sign and verify messages using only the public address. Since the public address is a RIPEMD160 hash how is it possible that I can verify a signature since I do not have access to the public key?


texts: Are DAG-based crypto currencies as secure as proof-of-work based blockchains?

texts: A key feature of blockchain based cryptocurrencies is that they provide inherently secure systems that don't rely on third parties. The newer DAG-based cryptos like Byteball are being touted as superior to blockchains because they have faster transaction times and eliminate the need for miners. However, these cryptos use something called "trusted witnesses" to resolve double spend conflicts. Isn't this inherently less secure than a true trustless system like Proof of Work? I thought that the whole point of a blockchain was to provide intrinsic security without the need for trusted third parties.


texts:
I'm looking for a Free API to get the market caps of Bitcoin.  There was a previous question about it.
However the documentation those endpoint are only to paid plans?
How can I get the total market cap for Bitcoin by day?


texts: Does anyone know why there are no Scrypt based merged mining pools out their yet? I would imagine that if it was possible it would have been done already. There is no problem to do it with SHA-256 based coins, so why can't we do it with Scrypt?


texts: Armory client shows transaction unconfirmed

texts:
I am new to btc and am using the Armory client. Yesterday I transferred some btc to wallet from my MtGox account. The wallet showed the btc received within minutes, but, after 12 hours it still shows as 'unconfirmed' in my Armory wallet, so my spendable funds is 0. Also, the status shows as not yet in the blockchain. So there is no block number assigned.

However, looking at the referenced transaction block on blockchain, I see my amount with another transaction, the block has 109 confirmations, and a block number. So I have two questions.

1) So it appears my Armory client isn't reflecting the block chain? What should I do? Will restarting the client cause me to lose anything? Will it update?

2) I am under the impression that it's the recipient who pays the transfer fees. I didn't set a fee when I sent the money, but my home wallet has a default fee built in, is that all I need? Can I lose transactions if the go unconfirmed?

3) What recourse do I have. I basically sent myself the bitcoin, but it appears I cannot spend them.

Thank you


texts: Will Upgrading Ram on Low End PC Make Core Sync faster?

texts:
I am a newbie to bitcoin. I am trying to sync a full node on my low end PC: 2g RAM, dual-core 2ghz, 250 gb regular HDD. It is in pruned mode. The initial 15% synced in a few days but now the process is fluctuating wildly around 2-7 weeks. Suffice to say it is very slow.
My main question is: how much will adding some RAM improve the syncing speed? And will adding new RAM reset the blockchain download?
I have already adjusted these settings: dbcach=900, banscore=10, listen=0
I am worried that putting in the RAM will "reset" the blockchain download and I will have to start syncing from 0% again. This already happened to me when I was tinkering with the dbcache setting - Which I will have to do again in order to take advantage of any new RAM(right?).
Anyway I hope that was a coherent question. Any response is very appreciated. :)


texts: Plot of distribution of all bitcoin transaction fees paid?

texts:
Is there a way to find and plot every transaction fee ever paid on the blockchain/bitcoin?
Background
I have read about transaction fees:

Though the average Bitcoin transaction may be around $25, for example, the median is closer to what most users will likely need to pay.

At that rate, if you want to send a transaction right away, the fastest transaction fee is currently around 102 satoshis/byte, according to bitcoinfees.earn. For a median transaction size of 224 bytes, this results in a fee of 22,848 satoshis, or $11. If you don’t mind waiting roughly a half hour, the price would be 83 satoshis/byte, or about $9. The price continues to slide down from there if you’re willing to wait even longer.

So this gives very useful info, but if I want to see the distribution of all historical transaction fees on the blockchain, how could I do that?
Also, because the value of bitcoin has changed a great deal over the past several years, it would be sensible to measure the transaction fees in USD equivalent (like the article does).
Is this easy to do (or even possible at all)?


texts: What precautions to take when working with only one or two confirmations?

texts:
I am providing a service that accepts Bitcoin. In order to speed things up a bit, I am planning to reduce the number of confirmations I require before I consider the money to have arrived.

I have read that it is quite safe to work with even a single confirmation if you take some precautions measures. What are those?

More specifically, with which options should I run bitcoind ?


texts: Hardware Wallet Security if Computer App (MEW, Ledger, Trezor) is compromised

texts:
I have bought a Ledger and Trezor.

I don't want to use My Ether Wallet, it gets hacked! I just want to go from the exchange to the Trezor. But, I have about 15 ALT COINS and I'm reading and hearing I can't use the Trezor/Ledger for all of them?

Is there a better alternative? How are hardware wallets secured against MEW hacks?


texts: How did Ripple handle DoS/DDoS during the ripplescam.com days?

texts:
I'm going to assume that during the days where Ripple was irrationally hated by some sub-population, a la the ripplescam.com site which used to be the first result on Google for "ripple coin" until Ripple set the decentralization plan in motion, that it was mercilessly DoS and DDoS attacked.

How were/are the servers protected?


texts: Does blockchain.info show all transactions?

texts: My client is still syncing, so I've been checking my transactions on blockchain.info.  It only shows two transactions although I know I should have more than that when I search my address.  I'm new to bitcoin, so I'm not 100% sure how it works.


texts: Are bitcoins (or fractions of bitcoins) labeled with IDs?

texts:
Many sources describe the double spending problem by saying something like "people cannot be able to spend the same bitcoin twice." [1][2][3] So are bitcoins, or the smallest allowable bitcoin fractions, distinctly labeled entities? My understanding was that they are not, and that the blockchain only records information on the amount of bitcoins each user has.

Also, if I am correct, what would double spending actually look like in the bitcoin system? If I send a transaction to one miner saying "I pay user X 1 bitcoin" and another transaction to a different miner saying "I pay user Y 1 bitcoin", then it seems like I haven't double-spent, but rather just paid two bitcoins in total, one to each user. Right?


texts:
I'm very new to this.
It’s hard to know for sure, but what’s most likely the case with the below transaction:

Someone sent 25.99 bitcoin to another person/organization
Someone sent 1 bitcoin to another person/organization
Someone sent 26.99 bitcoin to another person/organization


texts: Are there any C# Bitcoin libraries and/or mining pool software packages?

texts:
I was keen to write/launch a .Net pooled mining server as an exercise of getting into the Bitcoin universe.

Are there any C# ports of the libraries needed to achieve this?

If not

Are there any current tech mining servers that would suit my skill set, C#/Java?

I was keen to build out a site frontend & backend.


texts: Writing an article on Bitcoin for my school paper

texts:
I am writing an article on Bitcoin for our high school paper. What points do you think are important to include?

I'm writing this article for a high school paper, so please put it into those terms.


texts: What would happen to people's money if the Bitcoin project was discontinued?

texts:
Here in the Arabic world the biggest problem with online trading is the absence of a good, secure, and flexible money transfer tool or solution. I think Bitcoin is a great solution for this. I have an idea to start a payment processing service using Bitcoin in the Arab world.

I need to know what would happen if the Bitcoin project was discontinued for any reason.
What would happen to people's money?


texts: Customer pays in EUR and I receive bitcoin anonymously

texts:
I run a small business, and up to now I have always demanded to be paid in cash for my services.
I want to allow my customers to pay electronically through wire transfer, while remaining anonymous myself.
Is there a service which acts as a flexible always-ready EUR-to-bitcoin converter, such that my customers can pay electronically to a bank account owned by that service, whereafter an equivalent amount of bitcoin are transferred to me?


texts: What is the reason for other coins appearing like FTC and LTC?

texts: Is it simply just trying to be faster and better in some aspects than bitcoins?


texts: Unable to sendcoins using bitgo express apis

texts:
Trying to access API URL: https://test.bitgo.com/api/v2/tbtc/wallet/walletid38u5348t9yj958jtv985j89g5/sendcoins

But every time getting same response:

{
    "error": "You have called a BitGo Express endpoint but this is the BitGo server. Please have a look at the BitGo Express documentation: https://www.bitgo.com/api/v2/#bitgo-express-rest-api",
    "name": "ApiError",
    "requestId": "irfo34r5541k06grtyy4j6n33",
    "context": {}
}

Is there any correction in API route? Or how can I successfully send coins using this api?


texts: How to convert xpub ypub and zpub in Ruby

texts:
I'm looking to convert a Bitcoin extended public key from one format to another in Ruby.
In JS I've found https://github.com/jlopp/xpub-converter/blob/master/js/xpubConvert.js and Python https://github.com/lian/bitcoin-ruby/blob/master/lib/bitcoin.rb, from which I try to understand how it works.
But in Ruby I can't wrap my head around it. I use the Bitcoin::Util and my code is as follows:
require 'bitcoin'

include Bitcoin::Util

xpub = 'xpub6CUGRUonZSQ4TWtTMmzXdrXDtypWKiKrhko4egpiMZbpiaQL2jkwSB1icqYh2cfDfVxdx4df189oLKnC5fSwqPfgyP3hooxujYzAu3fDVmz'
prefixes = {
  xpub: '0488b21e',
  ypub: '049d7cb2',
  zpub: '04b24746'
}

decoded_key = decode_base58(xpub)
zpub_key = encode_base58(prefixes[:zpub] + decoded_key[8..])

puts zpub_key # => zpub6r8o2p9croV2A7Gh2VZn42iEEv7QCxJrXyqWDUcV7aMapn2nY464gJKzfFTs2Ry4UnCFT1pmvSru6u1KX4GyRs2ti4SYydbtH17TgCSRAgQ
puts base58_checksum?(zpub_key) # => false

The checksum is invalid and I don't understand how to make it work


texts: Changing a private key of a public Bitcoin address

texts:
I would like a way to change the private key of a public address, for this you'd of course require the current private key.
Is this at all possible?

I want to prove that it can be done, or prove that it cannot be done.


texts: Is there a chart available for the historical relationship between Bitcoin price vs difficulty?

texts:
All I've seen is this, from 2011-would like something more updated, if available.

Is there empirical data about a relationship between bitcoin price and difficulty?


texts: How to buy bitcoin to my local harddrive?

texts:
There are stories about people searchung dumps for their thrown away harddrives with bictoins with brazillions of money. I want to get such harddrive too :)
Is it possible nowadays? I.e. buy bitcois directly to my wallet, without any third party accounts?
I registered on CoinMarketCap and coinbase and looks like first site doesn't allow to buy bitcoins and another is maintaining it's own accounts with their security and 3rd party auth. But I don't want their accounts, I want my on my local selfcontained harddrive.
Is it possible?


texts: Does a vendor have to wait 10 minutes before a transaction is confirmed?

texts: I understand that a Bitcoin transaction, by design, will get one confirmation after an average of 10 minutes. Does that mean that a vendor that accepts Bitcoins will have to wait 10 minutes for a transaction to confirm? Let's say I am a sandwich shop and I decide to accept Bitcoins. A customer walks in and uses Bitcoin to pay for his sandwich. Do I, the sandwich shop owner, have to wait 10 minutes to confirm that he actually paid for the sandwich before I let him have the sandwich?


texts:
3-4 days ago, I transferred bitcoins from Virwox to my Electrum wallet, but this bitcoins didn't arrived, what can i do?
1JPSVx7hjcu7rR2Vr6nyz7z8mok3yryGZ


texts:
I am building an altcoin based on bitcoin 0.12, in chainparams we find :

consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = 0;
    consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = 999999999999ULL;
    consensus.vDeployments[Consensus::DEPLOYMENT_CSV].bit = 0;
    consensus.vDeployments[Consensus::DEPLOYMENT_CSV].nStartTime = 0;
    consensus.vDeployments[Consensus::DEPLOYMENT_CSV].nTimeout = 999999999999ULL;

what is 999999999999ULL?
should I use it in mainnet parameters instead this old dates ?

   consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].bit = 28;
    consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nStartTime = 1199145601; // January 1, 2008
    consensus.vDeployments[Consensus::DEPLOYMENT_TESTDUMMY].nTimeout = 1230767999; // December 31, 2008

// Deployment of BIP68, BIP112, and BIP113.
consensus.vDeployments[Consensus::DEPLOYMENT_CSV].bit = 0;
consensus.vDeployments[Consensus::DEPLOYMENT_CSV].nStartTime = 1456790400; // March 1st, 2016
consensus.vDeployments[Consensus::DEPLOYMENT_CSV].nTimeout = 1493596800; // May 1st, 2017

Thanks


texts: How can I create and distribute my own private blockchains in a scalable way?

texts: I would like to experiment with blockchains in a controlled environment for fun and/or development purposes. Is there a way to do this easily?


texts: Why the "Unspent Transaction Output Set" is called "UTXO", not "UTOS"?

texts: Just out of curiosity, the Wiki says UTXO means "Unspent Transaction Output", but what does each letter mean in the acronym?


texts:
(I know it's a duplicate question but the other answers are old and links are not working anymore)

I need to accept BTC donations from my GitHub page, and I was wondering how to do it.

I've created an address with Bitcoin Knots to receive payments, but from what I'm seeing the address will stop working after receiving the first donation, meaning that I should create a new one for each donation.

Of course this can't be done manually, so here are my questions:

Does the address really stop working after receiving one payment?
If yes, how can I automatically generate new addresses everytime?
(bonus) Is there a trusted way to move my BTC to a PayPal account?


texts: Bitcoin - Read transaction details from LevelDB

texts:
I am new to LevelDB and the way BTC keeps everything in the database. I went through article How does Bitcoin read from/write to LevelDB but was not able to get to the first step -
Transaction
246c5a81b6ad0dfc0dbc0b2ff5bde65ee1913f75a47d409b8ff8074a27ec1000

is identified in the LevelDB by:
c0010ec274a07f88f9b407da4753f91e15ee6bdf52f0bbc0dfc0dadb6815a6c24

How does the first string translates back to c0010ec274a07f88f9b407da4753f91e15ee6bdf52f0bbc0dfc0dadb6815a6c24? I understand the first character is c but what calculation makes the second string?
I am using .Net Core to read level DB using LevelDB.Standard nuget package (Assembly LevelDB.NET, Version=2.1.6.0)


texts: Why has there not been any confirmation for an entire hour? What do you recommend that I do to speed them up for myself and others?

texts:
I made a transaction an entire hour ago. Still in the damn "memory pool". I've had extremely varied experiences over the years with transaction speed, but I'm really starting to feel as if it's very strange that, with all the technical improvements to Bitcoin, it's still like this.
Frankly, I'm getting less and less enthusiastic about the Bitcoin-centered project I'm developing, simply because of the slowness of Bitcoin transactions as well as the large fees (compared to the amount sent).
I've been trying to understand how to use Lightning Network, but I've given up because there's just a maze of websites that redirect around and seemingly lack any Windows binaries. It feels like the Lightning Network is still at a very, very pre-release stage, not at all ready to be actually used.
Basically:

I find the transactions to be painfully slow to confirm/"go through".
I find the fees to be extremely large.
I find the Lightning Network to be a "non-thing". Not ready to actually be used.
I need much faster and cheaper transactions of money for my service to make sense.

Am I out of luck? Should I forget about charging small amounts and make my service much more "premium" so that the high fees and long waiting times will stand a chance of getting tolerated by people? Micro-transactions seem to be hopeless still?


texts:
I am installing bitcoin core. I cloned bitcoind source code from github.
Before starting to install it, I already downloaded all dependencies by referencing on here.
https://github.com/bitcoin/bitcoin/blob/master/doc/build-unix.md

$ git clone https://github.com/bitcoin/bitcoin.git
Cloning into 'bitcoin'...
remote: Counting objects: 113049, done.
remote: Compressing objects: 100% (3/3), done.
remote: Total 113049 (delta 2), reused 1 (delta 1), pack-reused 113045
Receiving objects: 100% (113049/113049), 101.22 MiB | 7.31 MiB/s, done.
Resolving deltas: 100% (78687/78687), done.
Checking connectivity... done.
$ cd bitcoin
$ git tag
...
v0.9.2rc2
v0.9.3
v0.9.3rc1
v0.9.3rc2
v0.9.4
v0.9.5
v0.9.5rc1
v0.9.5rc2
$ git checkout v0.9.5
Note: checking out 'v0.9.5'.

You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by performing another checkout.

If you want to create a new branch to retain commits you create, you may
do so (now or later) by using -b with the checkout command again. Example:

  git checkout -b <new-branch-name>

HEAD is now at b880967... Merge pull request #6169
$ git status
HEAD detached at v0.9.5
nothing to commit, working directory clean
$ ./autogen.sh
configure.ac:118: installing 'src/build-aux/compile'
configure.ac:12: installing 'src/build-aux/config.guess'
configure.ac:12: installing 'src/build-aux/config.sub'
configure.ac:37: installing 'src/build-aux/install-sh'
configure.ac:37: installing 'src/build-aux/missing'
configure.ac:707: warning: 'INCLUDES' is the old name for 'AM_CPPFLAGS' (or '*_CPPFLAGS')
configure.ac:707: warning: 'INCLUDES' is the old name for 'AM_CPPFLAGS' (or '*_CPPFLAGS')
src/Makefile.am: installing 'src/build-aux/depcomp'
configure.ac:707: warning: 'INCLUDES' is the old name for 'AM_CPPFLAGS' (or '*_CPPFLAGS')
configure.ac:707: warning: 'INCLUDES' is the old name for 'AM_CPPFLAGS' (or '*_CPPFLAGS')
parallel-tests: installing 'src/build-aux/test-driver'
configure.ac:707: warning: 'INCLUDES' is the old name for 'AM_CPPFLAGS' (or '*_CPPFLAGS')

I am going to install 0.9.5 release version. But what is this error ?

warning: 'INCLUDES' is the old name for 'AM_CPPFLAGS'

Even I ignored above warnings and executed make, but some errors occurred.
If I execute autogen.sh on master branch, there is no error.


texts: Is there a working Open source implementation of litecoin mining application for Linux without GUI

texts:
Is there a working Open source implementation of litecoin mining application for Linux flavours without GUIs (think debian, ubuntu server etc.)

I found a couple of implementations by developers but all of them are closed source.


texts:
Just turned my attention to mining and the concepts are quite new to me. First of let me be clear: I realize that my hardware setup is far from ideal for mining. This is also the reason why I do not want to pool, I would simply provide a too small a share. I will be CPU mining at first, ASIC later on.

I would however like to test my luck. Mostly just for fun, I'm completely fine with the idea of never actually solving a block. I see it more as a lottery. I just want to confirm my idea so that I am not missing something: Do I have a chance of solving a block?

If a block is solved every 10 minutes, and the difficulty goes up continously. Do I even have the time to attempt a solution? I understand that the current work has to be abandoned when a block has been solved, rigth? Is there, for example, a lag here that yields my efforts useless?

What are the odds? Are the actually the % of my speed vs the network's?


texts: How can create individual wallet for each user

texts:
I am going to develop an exchange website in PHP something like http://coinbase.com,
Now, I have setup the http://bitcoindevkit.com/ for it and its running fine generating new addresses in the same wallet,
but now I need to create a individual wallet for each user, so how can create individual wallet for each user and then I can able to create address on that wallet.


texts: What are recourse or non-recourse transactions?

texts:
This may not be a Bitcoin-specific question, but I still think it's better to ask it here.

I've seen discussions about accepting unconfirmed transactions, that it should not be done because of double-spend risks and such, but they also say that it's risky in non-recourse transactions.

So, what exactly is a non-recourse transaction? Is it related to whether the address is trustful? Or does it mean anything else?


texts:
Is there a way currently where an SPV client can send a TxID to a full node which is present in the UTXO set of the full node and have the full node not scan its entire blockchain to fetch the transaction data? Or under all the circumstances, the full node would always scan the entire blockchain to fetch the data?

Also, do the full nodes along with the transaction data also return the merkle proof to prove the validity of the data returned? I mean, how can an SPV node be convinced that the correct data has been returned?


texts:
Wondering what can be causing a Tx to take from from 19:48 (sent) to 22:44 (finally arrive to destination address). With Segwit implemented in both sides.
The mempool looks way lower than past days. Any ideas?
This was way scary. I used the Tx ID to check the Tx and all it came up with was a Not Found error in every block explorer.
At around 22h. the Tx suddenly appeared. In general, the mempool is way lower than previous days, but it has been a huge spike if looking at the 24 hours chart. Would this be the reason of the delay? Thanks.


texts: How to look about transtion is complated?

texts:
I'm trying to build my own blockexplorer, and to this i need to update a single transtion with confrims, my problems is i can't see how meny confrims there shut be and when my transtion is 100% complated.

i'm using RPC and bitcoin logic but what i'm working on is a multi-currency explorer based on bitcoin rpc syntax.

i use gettransaction (hash) and in this i can only se how many confrims, what do i wrong here?

i know i can say 6 confirms+ will be 100% complated, but the confirms still get bigger after 6 confirms, so i need to know when i shut stop to update my transtion on my blockexplorer project.


texts: Can you use any Bitcoin address as a Counterparty token receiving address?

texts:
I have a bunch of bitcoin addresses and I would like to just use them for receiving counterparty tokens. I've read that counterparty addresses are the same thing as a Bitcoin address. Is this correct? And if so, doesnt this mean every Bitcoin address can effectively receive counterparty tokens?

I also can't seem to find an option to import an existing Bitcoin address into the counterwallet website. I was only able to find an import sweep option. screenshot would be nice.


texts: How can I recover access to Ripple wallet

texts:
I have been 'playing' with my account at ripple.com. Among other things I tried to access another Bitcoin issuer (server, gateway?) by typing and saving WeExchange address in Advanced, Options, Web Socket. I think I may have typed in the incorrect address.

I was logged out and when I tried to log back in, I get "loading" icon shown 'forever'. In fact, I can't even get to the login page.

All in all, I cannot access my wallet/account anymore.

What can I do now? I filed a bug report at client GitHub but am hoping I may get a response here faster, plus it is not a bad idea to have the solution documented also here.

I am using Chrome on Windows.


texts:
I'd like to learn how segregated witness works, and I thought the raw transaction data would be a good place to start

If this is the structure of current transactions:

version | [inputcount] {[txid] [vin] [signature] [sequence]} | [outputcount] {value} {varint} {lockingscript} | [locktime]

What does a segregated witness transaction look like?


texts: Is there a way to undo transactions with a "too low" fee?

texts:
Suppose we reach a state where only transactions that pay a fee are accepted by miners. Further supposed that someone created a transaction using an old/odd client that allowed them not to send any fees.

In this case, what would happen to the transaction? Could it be undone? Would the coins be lost forever?


texts: How to import address to a wallet which runs in pruned mode

texts:
I am running Bitcoin Cash node with prune=99000 mode enabled. So, I tried to import addresses of BCH from another BCH wallet by using importprivkey method and I am getting an error: Rescan is disabled in pruned mode.

How could I import addresses in prune mode from another wallet?

Thanks!


texts: What happens once mining speed gets close to zero?

texts:
According to Wikipedia

  The number of Bitcoins created per block is never more than 50 BTC, and the awards are programmed to decrease over time towards zero, such that no more than 21 million will ever exist.

from which I naively conclude that as time passes less and less bitcoins will be mined and the total amount of bitcoins is limited, so after say ten (or whatever actual number - doesn't matter) years mining a bitcoin will be as unlikely as winning big in a lottery and maybe even news will report that one more bitcoin has been mined.

Are those right conclusions? What exactly happens once mining speed gets close to zero?


texts:
I am reading through BIP32's documentation and its implementation in Java on GitHub in the file supernode/api/src/main/java/com/bitsofproof/supernode/api/ExtendedKey.java.

Luckily, I was able to follow the code, but there are areas I am not sure about.

I have 2 questions:

I know it is in BIP32.json file, but why are we doing if ((sequence & 0x8000000)==0)?  It is a condition for master public key to child public key or master private key to child private key... but what sequence does for? if ( (sequence & 0x80000000) == 0 )
My second one is why we add 4 bytes.   Is there any detail document source I can find?

        extended = new byte[pub.length + 4];
        System.arraycopy (pub, 0, extended, 0, pub.length);
        extended[pub.length] = (byte) ((sequence >>> 24) & 0xff);
        extended[pub.length + 1] = (byte) ((sequence >>> 16) & 0xff);
        extended[pub.length + 2] = (byte) ((sequence >>> 8) & 0xff);
        extended[pub.length + 3] = (byte) (sequence & 0xff);
    }
    else
    {
        byte[] priv = master.getPrivate ();
        extended = new byte[priv.length + 5];
        System.arraycopy (priv, 0, extended, 1, priv.length);
        extended[priv.length + 1] = (byte) ((sequence >>> 24) & 0xff);
        extended[priv.length + 2] = (byte) ((sequence >>> 16) & 0xff);
        extended[priv.length + 3] = (byte) ((sequence >>> 8) & 0xff);
        extended[priv.length + 4] = (byte) (sequence & 0xff);
    }

Many thanks in advance.


texts:
For every "getwork" served by the pool, a Merkle root must be calculated for a block.  The run time of SHA-256 is proportional to the number of "chunks" of 256 bits, and a typical block will have thousands of these chunks (a block header has just has three, after preprocessing).  So the pool operator will need hashing power in the Mhash/sec range, roughly.  Am I right so far?

The individual miners need much more hashing power, but in a simpler form: here's a three chunk preprocessed block header; hash it with each of 0000_0000x through FFFF_FFFFx in the nonce field.  If hashing engines specialize on that simplicity, to make them cheaper and/or faster, then they don't work so well for the pool operators.

So if I'm a pool operator, or a solo miner, and I need to generate millions of Merkle roots, what are my options? Do the hashing engines (CPU/GPU/FPGA/ASIC) have an API I can use?


texts: Difference between a SegWit address and a P2SH address

texts:
Let there be an address 3ABCDEFGHJKDJHDH....

How can I understand if it's a SegWit address or a MultiSig address?


texts:
Request:

POST / HTTP/1.1
Host: de.btcguild.com:8332
Accept: */*
Accept-Encoding: deflate, gzip
Content-type: application/json
X-Mining-Extensions: longpoll midstate rollntime submitold
Content-Length: 44
User-Agent: bfgminer 2.99.1

{"method": "getwork", "params": [], "id":0}

Response:

HTTP/1.1 200 OK
Server: nginx/0.7.65
Date: Sat, 13 Apr 2013 21:55:23 GMT
Content-Type: application/json;charset=ISO-8859-1
Connection: keep-alive
X-Long-Polling: /LP/
X-Blocknum: 105632
Content-Length: 607

{
"error": null,
"id": 0,
"result": {
"data": "00000002df54a70cd769d78b9605c0a6574638db799e86bdd1183cfc000001c2000000009e7ed0ae4ccdb1dbf283f4ab608791f21b1a5f437f405f4f9ba0bb3b693506a95169d43c1a022fbe00000000000000800000000000000000000000000000000000000000000000000000000000000000000000000000000080020000",
"hash1": "00000000000000000000000000000000000000000000000000000000000000000000008000000000000000000000000000000000000000000000000000010000",
"midstate": "24a747c3d16eadbc1481bd342b5558b2e235301c11353faf4bc25a384102c9c9",
"target": "ffffffffffffffffffffffffffffffffffffffffffffffffffffffff00000000"
}
}

In the request/response what does id do?
In the response what is data and how is it generated?
What is midstate?
How does target work?
In the request what are these X-Mining-Extensions: longpoll midstate rollntime submitold parameters for?


texts: Seemingly random transactions on testnet

texts:
I'm testing my bitcoin marketplace site using testnet. Sometimes I'll simulate a payment from a buyer to a seller. In this scenario, my site generates a payment address and the fake buyer is supposed to send money to it. But before I do anything, a mysterious payment will be sent to the address and cause the payment to be partially or fully paid.

I'm not sure if this a bug with my site or the nature of testnet. Here's one such transaction: https://live.blockcypher.com/btc-testnet/address/miX7hFUHPciQaUC2QR88BMCUaR18aH2857/

I'm not an expert on blockchain but it seems like someone sent 0.68885375 BTC and the change valued at 0.00059542 BTC ended up going to my address instead. Why does this happen? Isn't the change supposed to go back to the sender?


texts:
The nonce header of a block has 32 bits. The vast majority of the time, none of the 2^32 nonces will result in a block hash below the target. So to continue mining, miners usually change the extraNonce in the coinbase transaction. But what will happen once all the bitcoins have been mined and there is no coinbase transaction anymore? I know this will only happen in 2140, but have we thought of a way to change the nonce range when it will be the case?
Thank you for your help.


texts: how is Proof of Burn policed to prevent simultaneous buying into multiple alt currencies?

texts:
Proof of Burn lets someone buy into an Alt Coin.

How is it policed so that someone doesn't "double-spend" by using the same Proof of Burn to simultaneously buy into Alt Coin 1 and Alt Coin 2?


texts: Why was Bitcoin Core in need of a fork of LevelDB?

texts: Why did Bitcoin Core fork LevelDB? What special needs does Bitcoin Core have, which require a specialized version of LevelDB?


texts: minerd disappears when i try to launch it with a batch file?

texts:
I started using pooler cpuminer v 2.3.3 yesterday and it works.
Today, it doesn't. I have no idea what the problem is, when I open the batch file, the minerd file disappears.

This is my command line thing:
http://pastebin.com/DyqstLrn

UPDATE: The thing that was causing the problem was Malwarebytes Anti-Malware. It works fine now, thanks for every one's support!


texts:
OP_PICK should take the nth element from the back of the stack and take it on top:
for input
xn ... x2 x1 x0
gives
xn ... x2 x1 x0 xn

I have used it in some scripts, but I've noticed some strange behaviour.

For instance, using the tool in:
http://webbtc.com/script
an input script
1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3
and an output script
19 OP_PICK
produces an error.
However 18 OP_PICK works. For 25 elements in the stack it should work in both cases.
The problem doesn't seem to be the number 19. If I add one input
1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3
the scripts works fine.

I have tried looking at the source code, but in
https://github.com/bitcoin/bitcoin/blob/ce56f5621a94dcc2159ebe57e43da727eab18e6c/src/script/interpreter.cpp
around line 551 I find:

            case OP_OVER:
            {
                // (x1 x2 -- x1 x2 x1)
                if (stack.size() < 2)
                    return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
                valtype vch = stacktop(-2);
                stack.push_back(vch);
            }
            break;

            case OP_PICK:
            case OP_ROLL:
            {
                // (xn ... x2 x1 x0 n - xn ... x2 x1 x0 xn)
                // (xn ... x2 x1 x0 n - ... x2 x1 x0 xn)
                if (stack.size() < 2)
                    return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
                int n = CScriptNum(stacktop(-1), fRequireMinimal).getint();
                popstack(stack);

I'm not really sure how OP_PICK is implemented. Can anyone point me to the code for OP_PICK or explain the errors?


texts: How to import an existing extended private key to bcoin?

texts:
I´m searching for a way to import an existing extended private key, exported from electrum, into a bcoin node. Reading https://bcoin.io/api-docs/ I can´t find a description to do this.

Am I missing a part or does someone have a solution for this?


texts: minimum hash rate of a pool to earn a reward

texts:
how much minimum hash rate of a new bitcoin pool should be to be able to compete with other pools to earn a reward?

how can I calculate that value?

any help appreciation


texts: Do we know who runs the big mining pools?

texts:
After looking at the hashrate repartition https://blockchain.info/fr/pools.
It seems to me that bitcoin is quite centralized, and that two big actors (mining pools company who run the bitcoind server) like BTC guild and GHash.IO suffice to obtain the mythical 51% computing power, allowing various kinds of attacks.

How do we know that these two guilds are not the same person, or will not collude?
In the event that such collusion happens, and malicious double spending* occurs or other attack occurs, how do we detect it? What happens when we do detect it?

*Double spending doesn't have to be malicious: https://blockchain.info/fr/double-spends


texts: Running TorBB on host machine while running Whonix VM setup as guest on the same physical box

texts:
I've currently set up Whonix VMs using Virtual Box on OS X 10.11.6. Before that I was using a Bitcoin-qt with Tor Browser Bundle.

Now I'm having question what is a best way to use bitcoin+tor setup in my case?

Could it be dangerous for my anonymity to run TorBB+Bitcoin-QT setup on host(OSX) machine while running Whonix VM setup at the same time?

I guess the best way is to transfer somehow my bitcoins to Whonix Workstation, and set up there something like a thin wallet (electrum or multibit)? Or could I just leave the TorBB+Bitcoin scheme on my OSX, running it just for Bitcoin, while using Whonix for all other anonymous stuff (like browsing etc.)?

Hey, community, how would you address this situation?

Thank you very much!


texts: Why are there ETH addresses in bitcoin wallet.dat?

texts:
So I have a lot of addresses or pkscript listed in my wallet.dat files that begin with 0014....all...numbers.

There is bitcoin address on the same line starting with a 3.

When I strip the 0014 and search the blockchain, they all bring up an ETH address with 0 ETH.

Who can explain this?


texts:
Can anyone plz point out a way to derive the BlockHash from TxHash using API ?

Lets assume I am studying the following...

https://blockchain.info/rawtx/5602487e624ee14193f646e29a9ac203335bc962b30155b66d142ab15f79018c

{"block_height":277586,"time":1388338452,"inputs":[{"prev_out":{"n":0,"value":1683888660,"addr":"14RfKeVn9PrG4CLuyzJYUXiFdqyd7Amjp5","tx_index":102576735,"type":0}}],"vout_sz":2,"relayed_by":"178.194.214.181","hash":"5602487e624ee14193f646e29a9ac203335bc962b30155b66d142ab15f79018c","vin_sz":1,"tx_index":105080382,"ver":1,"out":[{"n":0,"value":1483888660,"addr":"1FxmczX5yUXn6GAZBCJy2Uc25NgzpQNEtM","tx_index":105080382,"spent":false,"type":0},{"n":1,"value":200000000,"addr":"1NbX8RDmNJ2J36LBTBgTU6bwcqdX7Udv2M","tx_index":105080382,"spent":true,"type":0}],"size":225}

I have "block_height":277586

Now, how do I find out the block_hash of this ?


texts: How can I sign a message with a litecoin private key and also generate a litecoin address from a string?

texts: I'm working with bitcoinjs, but is there a litecoinjs equivalent? I want to be able to sign and verify messages with my litecoin private key and also generate litecoin addresses from a string. How would one go about doing these functions with a javascript library if one exists?


texts: How does one "authenticate" a bitcoin user?

texts:
What is the minimum standard for authenticating a bitcoin user. Would it be enough, for instance to verify that someone named "Tom Au" will answer to that name at this email address? Or are more detailed checks required?

Edit: Authentication would mean that I am what I say I am, that I am a human being and not a robot,and that I can do what I purport to be doing (trading Bitcoin).

Is there a public, or central registry for computer users?

In this event, would something as strong as "hashing" be needed for data storage and retrieval?

Would a web of trust concept work for the bitcoin community?


texts: Why do we need block hashes in blockchain?

texts:
I believe there are around 3 types of overall hashes that we deal with in Bitcoin.

block hashes
Merkle tree hashes (makes transactions tamper proof by hashing them up to the Merkle root)
public-private key hashes (used as part of the UTXO model to generate addresses derived from the public key)

I get the functionality of all hashes other than 1st.
Is it only there for reference ?? We could have used block height as block reference and traversal and added nonce in that for our POW requirement.


texts: Natural Language Processing and Blockchain?

texts:
This question is about one of the applications of the Blockchain in Artificial Intelligence. I am not very familiar with Natural Language Processing and
I see that there is a Blockchain platform named "Graphgrail" to employ Blockchain for NLP and AI.
In its whitepaper is mentioned that:

7.1 WHY DO WE NEED BLOCKCHAIN AND TOKENS:
Provision of the possibility of using data on a platform with mutual benefit for the owner (?) and
buyer (?). The Token allows the platform to hash in the blockchain
platform the users and the results that they receive when training a
neural network, downloading and / or spacing data. This allows other
users, with the permission of the owner, to analyze the usefulness of
the data or the trained models, use them and leave comments about the
quality of the decisions applied. On the other hand, thanks to the
protocol, users have the opportunity to monitor hashes to their
blockchain at any time and receive an appropriate reward for their
work, which they themselves will assign. This guarantees both parties
the desired benefits.

It's not yet clear to me HOW exactly blockchain can help the user for an NLP operation?
What does mean : "The Token allows the platform to hash in the blockchain platform the users and the results that they receive when training a neural network" ? And what is the advantage of hashing the users and their results? (Is it for data integrity?)
And who is "owner" and who is "buyer"?
And do you think in general is it logical to employ blockchain for NLP? and if so, is there an example?


texts: Effect of internet connection speed on solo mining

texts:
I have a set of PCs hasing at 100 kH/s and currently the network difficulty is 2674.36329706.

My power usage is 200 W, and as per https://www.litecoinpool.org/calc?hashrate=100&difficulty=2674.36329706&power=200&energycost=0.12&currency=USD

the probability of me finding a block in 30 days is 2.23%

However, my internet speed has been curtailed at 52 kilobytes-per-second and I'm wondering if that changes the above probability from 2% to zero? ie, do I need to have a great internet connection to even have that 2% chance?


texts: There are quite a lot of bitcoin faucets on the Internet. They give away bitcoin for free, but where do they come from? Won't the faucet operator lose money?


texts: How does an exchange cover a "run on the bank"?

texts:
This is not a duplicate! There are several similar questions, but they concern mining or other specific questions. This is not about mining.

Lets look at a specific situation. Lets say the value of bitcoin surged to something ridiculous. Lets say several billion dollars per coin. Now in this hypothetical situation, if everyone on the exchange (or even just a few individuals) decided, "You know what, that's enough for me" and decided to cash out, how would the exchange cover this? There is no way they could handle the surge. So where does the money come from? Of course, if you just keep it and spend your new riches using bitcoin then it doesn't matter, but I fail to understand how the idea of digital currency doesn't break down in this case. Perhaps this is a conceptual flaw of understanding on how the market works. Perhaps the money would have to be there in the first place to have driven the price up so high. Can anyone help explain please?


texts: Can there be a blockchain without mining?

texts:
This is a question about Blockchain in general, not about Bitcoin as a currency on top of Blockchain technology.

Let's say I want to issue a vote on top of, lets say, multichain. I would issue an asset called "voting_right". Let's say I have 1000 participants, so I create 1000 voting rights and send each participant address one voting right. Everyone can either transfer their vote to somebody else or directly to a vote option.

I don't have given anyone mining permissions, because I don't want anyone to "illegally" earn voting rights. On the other side, I require miners to collect the votes into blocks and prevent double-voting.

Can there be a Blockchain without miners?
If no, what I am assuming, is there any danger if I, let's say create two mining-enabled multichain nodes (with 0 reward), 100% controlled by me? How can others trust me?


texts: So let's say I have multiple bitcoin addresses (some of them already received bitcoins), created a new bitcoin address, received bitcoins on it and would like to use the very same address to send them elsewhere - how can I do that?


texts: How output transaction works in Bitcoin?

texts:
Click here for reference.

  Note also that an output can be used only once. That's why there's a concept of "change address" in the bitcoin ecosystem: if an output of 10 BTC is available for me to spend, but I only need to transmit 1 BTC, I'll create a transaction with two outputs, one with 1 BTC that I want to spend, and the other with 9 BTC to a change address, so I can spend this 9 BTC with another private key that I own.

So what will happen if an output of 1 BTC is available for me to spend, but I want to spend 10 BTC?

Note: It is a general question and is not specific to any API feature.


texts: I was scammed, told I had bought bitcoin and that it had been put in my wallet. I have never had a bitcoin wallet

texts: I am trying to recover my money through my bank. How do I prove that I have never had a wallet for this currency. If someone else created the wallet how do I identify where it is?


texts:
Stealth addresses are mentioned in the context of privacy of bitcoin transactions. What are they and how would they work?

Can they provide 100% anonymity?


texts: Are there any services to tell black list address?

texts: I'd like to know the addresses used for a fraud, in order to make a service for analysing bitcoin blockchain. If you know the service for that, could you tell me it?


texts: Are there scientific studies related to the Bitcoin technology?

texts: Besides “Bitcoin: A Peer-to-Peer Electronic Cash System”, which is more like a brief description of the general framework, are there other ‘scientific or research grade’ studies about Bitcoin technology? Can similar decentralized crypto-currency models be found in the literature?


texts:
How does proof of work function?

Why does the "work" in proof of need to have zero utility for the economics of the cryptocurrency to be viable.


texts: How to send bitcoins from selected address on blockchain.info wallet?

texts:
I have wallet on blockchain.info, with two addresses. I want to send some bitcoins from only one of them using quick send. I don't see where I can select source (input) address.
Where I can see my default (master?) address?
How can i change it?


texts: where can I get resource such as Blockchain technology in C++

texts: I have found a lot of pdf files about Ethereum smart contract and JavaScript cryptocurrency. I still want to know about resources such as C++ cryptocurrency. Let me know about some good resources.


texts: The bitcoind 'gen=0' setting - implications?

texts:
I have read that when running a simple standalone instance of 'bitcoind', you should generally use 'gen=0', since it's highly unlikely you'll ever mine a block on your own.

What I don't fully understand is how this relates to transaction procssing.

If I use 'gen=0', does that mean I have no hope of getting transaction fees, either?

In other words, with 'gen=0', is my client not really participating in processing transactions at all?

Is block mining (to generate new bitcoins) a somehow separate process from processing transactions?


texts: How to decode messages embedded with btcmsg?

texts:
btcmsg seems to be using proprietary software to encode and decode messages in the blockchain.

Did they expose their algorithm? If they shut down tomorrow, how can someone decode messages he stored using their service?


texts: Anonymous transactions technology for a cryptocoin?

texts: I’m thinking of investing in a cryptocoin with anonymous transactions feature. So far there are 3 well-known technologies for that: coinjoin (Bitcoin), masternodes (Darkcoin) and CryptoNote (Bytecoin). CryptoNote looks more appealing due its innovative ring signatures technology. Can anybody explain which option would be the best and why?


texts: bitcoin-cli very slow to respond to RPC calls (Raspberry Pi)

texts:
Running Bitcoin 0.11 on Raspberry Pi 2 (Quad core 900MHz 1GB RAM, 128GB Flash Drive for blockchain, 8GB SD Card for OS and software).

Blockchain is fully synced, 13 connections.
In htop, I see I'm around 700/862MB RAM, 1/99MB Swap. 1 processor is up around 90% but the other 3 are down in the <5% range.

I SSH into the pi (running bitcoind, no GUI) and some commands take forever to get a response. Sometimes getinfo or getpeerinfo will take 30-60 seconds to print out. gettxoutsetinfo takes way longer: almost ten minutes!! I don't see any resources being maxed out in htop during this time.

I know this is a low-power machine, maybe the UTXO set hash in the gettxoutsetingo command is what's specifically taking so long in that case.

Can I adjust any settings either in the RPi OS or bitcoin.conf to get snappier performance? Ideally I would like to run a few python scripts that use RPC, triggered by bitcoin's blocknotify=...


texts: Is blockchain.com the only place where you can see the blockchain?

texts:
I've been investigating Bitcoin and when I would try to find out where the blockchain is stored, I was told that it is stored on everyone's computer. Then I would ask where was the blockchain stored on my computer and the response was it is stored in your wallet.
Since Bitcoin is decentralized, I supposed that it must be found anywhere. But I found no information about that.
My question is actually: Where can I see the blockchain without going to blockchain.com?


texts: getblockchaininfo returning excessive "soft fork" info

texts:
The blockchaininfo command is now returning a lot of "softfork" information.

Is there a way I can get other fields without the softfork blob?


texts: Why would you need to "catch up" in the 51% attack?

texts:
There is a lot of information on the 51% attack where an attacker is able to branch the chain and "catch up" and build a new branch that is longer than the old branch. Other than requiring more than 50% of the network's computing power, the biggest thing that makes this attack infeasible is that the further behind an attacker is, the harder it is to catch up. Some places say that this means that a payment receiver can simply wait for a couple of blocks to go by and by that time is becomes infeasible for an attacker to catch up from that far behind.

But why would an attacker ever have to "catch up"? Couldn't an attacker with 51% of the network's power branch the chain as soon as a new block is released and work on that branch in secret? Then at any point the attacker could publish his branch, effectively reversing any transactions that occurred between the time he branched the chain and the time it is published to the network.


texts:
I needed help in understanding how to calculate the GE for a SHA256 implementation. I need to calculate the GE of individual functions in the SHA256 hashing algorithm.

Could anyone please direct me to an appropriate paper/book that explains this in detail?


texts:
I did a stupid custom validation script in P2SH where after check signature, check if OP_3 is equal of OP_3. Now I want to move the same logic in P2WSH multisignatue 1-3.

it's my script

$ bitcoin-cli decodescript 512103dee28d1db5d8b92181ac5baa04c28c01d2b14d19a3c6adaf7bd3430d0c6c8146210343a6f95f841b48ba2b97822a546976aea951e5a1f1c0a10078fdbbded165dbe32103f2f0a25413bb97af3b2ef21694fab820146e2e1bed41b6528a9ce6dd218d9bd353AE755387
    {
      "asm": "1 03dee28d1db5d8b92181ac5baa04c28c01d2b14d19a3c6adaf7bd3430d0c6c8146 0343a6f95f841b48ba2b97822a546976aea951e5a1f1c0a10078fdbbded165dbe3 03f2f0a25413bb97af3b2ef21694fab820146e2e1bed41b6528a9ce6dd218d9bd3 3 OP_CHECKMULTISIG OP_DROP 3 OP_EQUAL",
      "type": "nonstandard",
      "p2sh": "2N6SWbfkKVhPhYXx9idgDG5AVTPSAMNG5tY",
      "segwit": {
        "asm": "0 e976e1bb7c72f7f82132c706b3e8f2ee5673b9fa7172035aab9be62e8877d37c",
        "hex": "0020e976e1bb7c72f7f82132c706b3e8f2ee5673b9fa7172035aab9be62e8877d37c",
        "reqSigs": 1,
        "type": "witness_v0_scripthash",
        "addresses": [
          "bcrt1qa9mwrwmuwtmlsgfjcurt868jaet88w06w9eqxk4tn0nzazrh6d7qm9wxcj"
        ],
        "p2sh-segwit": "2NCLN7WkLL7dt56XyMVWH3QxDv2ytJGEw6d"
      }
    }

then create the transaction, manually sign it and add 3 in my Witness field, Then I have

"5300"<signatures><witness script>

But I get an error during send transaction TX decode failed
The I change 0x5300 with 0x010300 and it works.

The Question is, are there some limitation on custom script in P2WSH? I didn't find in BIP.
In P2SH I able to add 0x53 in scriptSig and send transaction without problems


texts:
I am on Ubuntu 16.04, with the latest version of Bitcoin Core, synced and working.

I would like to know why is there a little delay of approximately 1 sec, sometimes more, before a received transaction appear on the console when we run for instance bitcoind -printoconsole, if I check the tx on blockchain.com for instance, I can see that the transaction were received 1 or 2 sec before I even see it on my node, why is there a delay ? I have try on another ubuntu server with a super fast connection and it's the same thing. By the way, it's the same thing when I send a Tx, it's submitted and appear on the network 1-2 secs after.

So my question is why is there such a delay even on a node ? Is it possible to reduce it ?

I have already asked the same question on the bitcoin repo on github and someone told me that it is an intentional delay against attackers, but what I don't understand is why blockchain has access to it before node ? If they can it mean that we can too right ?

Just like when few years ago and even months, some brainwallet were swipped within milliseconds.

Thanks in advance !


texts: Are there any Scala libraries/implementations/projects on bitcoin?

texts: There are quite a few Java libraries and I am building my Scala code on BitcoinJ, but obviously, native Scala libraries would be quite a bit more elegant. Has anyone tried?


texts:
I'm trying to understand the following two sites that display UTXO information. If I can figure out the method, that would be a bonus for this question but if I can't can someone explain why the two sites measure UTXO differently?

The following website I think adds utxo from the gensis block: https://statoshi.info/dashboard/db/unspent-transaction-output-set?panelId=6&fullscreen

This website's value is way higher than the one of the previous: https://charts.bitcoin.com/btc/chart/utxo-set-size#5moc

Am I missing that these are different charts? How can I reproduce them if I decide to create the charts myself?


texts: What does it mean to "password protect" your wallet on Multibit?

texts:
Isn't my wallet (i.e. my private key) already private? What does it mean to set a password for it? I assumed it encrypted the wallet file, but this answer seems to point otherwise. How can they verify the password? I don't feel very comfortable sending it to a server, and it doesn't seem any safer to store a password with the wallet file than just have a wallet file without a password. However if it does encrypt the wallet, what software is used?

I'm very unsure of multibit, it seems very non-transparent. The wallet file seems to be a binary file instead of a plain text one with my key (granted plain-text "isn't safe", but so isn't a binary file that can be used by an attacker on his multibit client). I don't even know what multibit is doing with that file...

Thanks... Noob here.


texts:
I read this in a IRC exchange:

  verifies your txns against a random node that you don't control. if for some reason that node went rogue, you might have accepted an invalid txn

What is a txn?


texts:
It is not looking like Bitcoin Core will be moving from GitHub anytime soon (unless forced to).
How does an individual access the Bitcoin Core repo and contribute to it in the case that GitHub boots Bitcoin Core or the individual off GitHub?
What should an individual do in advance to prepare for this scenario?


texts:
I can see http://tbtc.blockr.io/ time of block are showing "right now". When I click "all blocks" the time is two hours ahead of "now". I don't think it's blockr time zone problem, because

1) when I submit transaction, it will show correct time

2) my bitcoinj wallet also showing future time against

System.currentTimeMillis();

which is UTC time. (I use ntp and it happens on two different computers)

Anybody have an idea why this is happening?


texts: Where can I find historical exchange rate data for Dash (ex DarkCoin)/USD?

texts: Is there a public data provider that allows to download the full history of Dash (ex DarkCoin) vs. US Dollar exchange rates?


texts:
My client asked me to use the bitcoin blockchain to store some photos hash as proof of existance.

I read that pulling this data on into the blockchain is not free

1) How much does it cost ?

2) Who gets that money ?


texts: Importing a private key (paper wallet) to Bitcoin Core client, while offline, is not actually importing

texts:
Trying to import a paper wallet to bitcoin core, while not having a fully synced node.
I've used: importprivkey 1Lblablablablabla "MyLabel" false
It returns "null", which I understand means successful import.
But then when I use dumpprivkey with the associated public address, it says there is no private key associated with the address.
I also look in the GUI and can't find any clue as to where that private key has been imported.
So basically the wallet is not giving me errors of failed import, but also not actually importing the private key.
What should I do?


texts:
In the BIP by Pieter Wuille it is told that the key prefixed version of Schnorr signature is needed when the scheme is used in combination with BIP32's unhardened derivation. Could someone provide an example showing this necessity? I couldn't figure out one by myself.

Always in the BIP, when coming to batch validation we can see that there is the need for random number generation. Again, could someone provide an example showing that the simpler version is insecure? I found out that the reason is the so called "cancellation attack". I would like to figure out how it can be exploited.

Thanks in advance for your answers!


texts:
I remember some where was table and python scrypt for do this , when reinstall my debian i was lose this script.

Example we hv uint256S("00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
what is = 0x1d00ffff


texts: I bought bitcoins about a year half ago and my hard drive broke and i managed to recover them using a recovery tool that found wallet.dat from a deleted wallet on another hard drive but its courrped and wont work at all. i tired something to do wtih python dbdump.py --wallet but it failed, is there anything i can do any help would be great.The wallet.dat is only 112kb i dont know if that matters.


texts: I am using bitcoin.rpc.RawProxy to connect to bitcoind and scrape the data. But I am getting an error when I gettransaction and I have to reindex the blockchain. Thus I am wondering how I set the txindex to 1 so I can reindex and continue.


texts:
I met this guy online and he wanted to teach me trading. so he  said I needed to log in my wallet in my wallet which I did then he sent a link of team viewer (https://www.teamviewer.com/en/download/windows/).

The next thing my wallet was sending my bitcoin to an address.. I did not do this, how did it happen? Everything happened so fast.. Nobody knew my password or even my wallet key... How did my wallet send the initiate the transaction by itself?


texts:
I'm a newbie so this might be a stupid question, but on Blockchain, it says I have made two transactions however I only did one transaction and the overall thing does not make sense to me. Could someone please explain where this second transaction is from and what the 10 BTC on the right means?

This is the page: https://blockchain.info/address/12b6BMrGnqm5eHiLGejWuESurbVxwVU4gk

Thanks


texts:
I have an application where I pay users in bitcoins (microtransactions). I am also starting to use Bitcoin core.

What I want:
Pay the minimum possible as fee of a custom transaction (1 input and x outputs). I need to pay the minimum because this difference is very important to make my app viable.

I saw that here are different costs/byte. And I see that 0 fee transactions can take forever. But my doubt is that if I pay a minimum of 1 to 10 Satoshis/byte, could the transaction be stucked for ever? or it will spent as maximum 240 min (as the page shows right now I know it can vary).

I also "don't care" about the transaction time spends to reach its destination (to be confirmed) as much I would like 5 days more or less to confirm.

Questions:

Can it take forever if I pay the minimum or it will also be but in some days.
What minimum of fee / byte do you recommend me?

Thank you for reading!
If you don't understand something, please make me know and I'll try to explain better.


texts: How would the network respond to an ability to crack the private keys?

texts:
I'm wondering how future-proof the BTC network security is.

Suppose some technological advancement (e.g. quantum computing and/or some ingenious algorithm) were to allow easily cracking the private keys.

How would the BTC network respond to such an ability if it was anticipated at least a year or so in advance? What would the response be if one morning such an ability was discovered/announced?


texts:
What is the difference or the meaning of these two headers of input scripts?

1) 4730440220
2) 4830450221

I see a lot of them in transactions but I don't understand the difference.

Thanks


texts: Why does Ripple use Blockchain technology in the first place?

texts:
This is what I understand Ripple's use-case with banks.

You and I announce to a trusted third party that $10 million of my money should now be considered yours. This third party isn't a middleman who holds debt,  - it simply keeps track of IOUs and regularly announces to all parties who owes who how much. The ACH system in the US (a.k.a. "Direct Deposit") works this way.

So, for the most part, bank's don't actually send money to each other at all - they just keep track of who owes who how much. Actually settling those debts, if it happens at all, has to happen outside of the systems above.

Ripple, as I understand it, basically a distributed public ledger of IOUs. (And those IOU's can themselves be traded as currency, when they're written by a trusted party.)

But why ripple uses Blockchain technology. Here doesn't Ripple acts as a middle-man? Why not to use central DB's? What is the difference of Ripple from a company that creates network of banks but rely it's technology on Oracle DB and related API's for example? Also who are the miners and nodes of the Ripple's use case with banks?

Thanks.
Firat


texts: Does ad hoc adoption of private blockchains make the financial system vulnerable to tampering?

texts: The security of a blockchain network depends on how many nodes are participating in that network. More number of participating nodes, implies better security. Currently, many financial institutions are integrating  a "private" blockchain into their operations. Since the number of participating nodes in a private blockchain is likely to be far smaller than the public blockchain, does it mean that it is easier to tamper the private blockchain? If that is true, then does it imply that ad hoc private networks of blockchain adopted by financial institutions will be less secure than a big public blockchain network?


texts: Bitcoind daemon get received notifications by public address

texts:
For my project I need to check the balance of a public address using bitcoind. Can I do that without importing the private key, only by public address?

Need solution no dependence, because I tried with blockchain.info API and after x requests, they blocked me. I need to check a lot addresses every 30 minutes.


texts:
I have waited for nearly 24 hours for my BTC transfer to my new wallet.

Does the amount I sent fluctuate with the markets?

For example, If I send .01 BTC and while the transfer is in progress, the value of BTC goes up, will I still receive the profit when it arrives to me?


texts: Will this Transaction still arrive or was it stolen?

texts: Was this Transaction stolen or did i make a mistake? ae6f689cb77a5eceea9eed5a91ce51f940fef2b8832946e747d0d0d788c3d9b3


texts: Python - Querying bitcoin's block header using leveldb

texts:
I am facing a stupid problem. I am trying to read bitcoin/blocks/index leveldb using plyvel. I've set up a regtest and i know there is a block with the hash :

27ce8199dee22f96e4f392dec29ef207fcd8a3c9e43b7d58cb40a5ba01af674b

I am trying to query it using plyvel.

Note that I already read the topics :

How does Bitcoin read from/write to LevelDB

What are the keys used in the blockchain levelDB (ie what are the key:value pairs)?

https://en.bitcoin.it/wiki/Protocol_documentation

Then, I know I have to swap the endianness so it becomes :

MYVAR = "4b67af01baa540cb587d3be4c9a3d8fc07f29ec2de92f3e4962fe2de9981ce27"

Thus, I should query something like :

b + (byte) MYVAR

However I do not get how. I guess I missunderstand something in encoding. I tried :

db.get(b'b4b67af01baa540cb587d3be4c9a3d8fc07f29ec2de92f3e4962fe2de9981ce27')
db.get(b'b'+b'4b67af01baa540cb587d3be4c9a3d8fc07f29ec2de92f3e4962fe2de9981ce27')

..

Then, I opened the bitcoin/blocks/index leveldb using a gui explorer and I noticed the key for this block is :

\x62\x4b\x67\xaf\x01\xba\xa5\x40\xcb\x58\x7d\x3b\xe4\xc9\xa3\xd8\xfc\x07\xf2\x9e\xc2\xde\x92\xf3\xe4\x96\x2f\xe2\xde\x99\x81\xce\x27

which is \x62 corresponding to the "b" + the hash with \x (escaping caracter ? I know here is my misunderstanding on hex encoding)

and obviously

db.get(b'\x62\x4b\x67\xaf\x01\xba\xa5\x40\xcb\x58\x7d\x3b\xe4\xc9\xa3\xd8\xfc\x07\xf2\x9e\xc2\xde\x92\xf3\xe4\x96\x2f\xe2\xde\x99\x81\xce\x27')

perfectly works

I also tried these methods :

https://stackoverflow.com/questions/5649407/hexadecimal-string-to-byte-array-in-python

No one of them works and I really don't get why :

bytes.fromhex(hash)
bytearray.fromhex(hash)

Thank you in advance